diff --git a/build.bat b/build.bat
index 51f73739..d8a2ca72 100644
--- a/build.bat
+++ b/build.bat
@@ -40,6 +40,7 @@ if "%~1"=="release" if "%~2"=="" echo [default mode, assuming `raddbg` build] &&
 set auto_compile_flags=
 if "%telemetry%"=="1" set auto_compile_flags=%auto_compile_flags% -DPROFILE_TELEMETRY=1 && echo [telemetry profiling enabled]
 if "%asan%"=="1"      set auto_compile_flags=%auto_compile_flags% -fsanitize=address && echo [asan enabled]
+if "%opengl%"=="1"    set auto_compile_flags=%auto_compile_flags% -DR_BACKEND=R_BACKEND_OPENGL && echo [opengl render backend]
 
 :: --- Compile/Link Line Definitions ------------------------------------------
 set cl_common=     /I..\src\ /I..\local\ /nologo /FC /Z7
diff --git a/project.4coder b/project.4coder
index a725e0d6..3e46160f 100644
--- a/project.4coder
+++ b/project.4coder
@@ -46,7 +46,7 @@ load_paths =
 commands =
 {
   //- rjf: [raddbg]
-  .f1 = { .win = "raddbg_stable --ipc kill_all && build raddbg telemetry",                                                       .linux = "", .out = "*compilation*", .footer_panel = true, .save_dirty_files = true, .cursor_at_end = false, },
+  .f1 = { .win = "raddbg_stable --ipc kill_all && build raddbg telemetry opengl", .linux = "", .out = "*compilation*", .footer_panel = true, .save_dirty_files = true, .cursor_at_end = false, },
   
   //- rjf: [textperf]
   // .f1 = { .win = "raddbg_stable --ipc kill_all && build no_meta telemetry textperf && raddbg_stable --ipc bring_to_front && raddbg_stable --ipc run", .linux = "", .out = "*compilation*", .footer_panel = true, .save_dirty_files = true, .cursor_at_end = false, },
diff --git a/src/base/base_math.c b/src/base/base_math.c
index 4f5903c5..7a65b45b 100644
--- a/src/base/base_math.c
+++ b/src/base/base_math.c
@@ -386,6 +386,21 @@ derotate_4x4f32(Mat4x4F32 mat)
   return mat;
 }
 
+internal Mat4x4F32
+transpose_4x4f32(Mat4x4F32 mat)
+{
+  Mat4x4F32 result =
+  {
+    {
+      mat.v[0][0], mat.v[1][0], mat.v[2][0], mat.v[3][0],
+      mat.v[0][1], mat.v[1][1], mat.v[2][1], mat.v[3][1],
+      mat.v[0][2], mat.v[1][2], mat.v[2][2], mat.v[3][2],
+      mat.v[0][3], mat.v[1][3], mat.v[2][3], mat.v[3][3],
+    }
+  };
+  return result;
+}
+
 ////////////////////////////////
 //~ rjf: Range Ops
 
diff --git a/src/base/base_math.h b/src/base/base_math.h
index e6f76423..eb322865 100644
--- a/src/base/base_math.h
+++ b/src/base/base_math.h
@@ -545,6 +545,7 @@ internal Mat4x4F32 mul_4x4f32(Mat4x4F32 a, Mat4x4F32 b);
 internal Mat4x4F32 scale_4x4f32(Mat4x4F32 m, F32 scale);
 internal Mat4x4F32 inverse_4x4f32(Mat4x4F32 m);
 internal Mat4x4F32 derotate_4x4f32(Mat4x4F32 mat);
+internal Mat4x4F32 transpose_4x4f32(Mat4x4F32 mat);
 
 ////////////////////////////////
 //~ rjf: Range Ops
diff --git a/src/render/d3d11/generated/render_d3d11.meta.h b/src/render/d3d11/generated/render_d3d11.meta.h
index 5f5e1f12..6fd7f833 100644
--- a/src/render/d3d11/generated/render_d3d11.meta.h
+++ b/src/render/d3d11/generated/render_d3d11.meta.h
@@ -279,8 +279,7 @@ str8_lit_comp(
 "    corner_radii_px.w,\n"
 "    corner_radii_px.z,\n"
 "  };\n"
-"  float2 cornercoords__pct = float2(\n"
-"                                    (c2v.vertex_id >> 1) ? 1.f : 0.f,\n"
+"  float2 cornercoords__pct = float2((c2v.vertex_id >> 1) ? 1.f : 0.f,\n"
 "                                    (c2v.vertex_id & 1)  ? 0.f : 1.f);\n"
 "  \n"
 "  float2 vertex_position__pct = vertex_positions__scrn[c2v.vertex_id] / viewport_size;\n"
diff --git a/src/render/d3d11/render_d3d11.c b/src/render/d3d11/render_d3d11.c
index f3ba394c..dca4586c 100644
--- a/src/render/d3d11/render_d3d11.c
+++ b/src/render/d3d11/render_d3d11.c
@@ -669,11 +669,11 @@ r_tex2d_release(R_Handle handle)
   ProfBeginFunction();
   OS_MutexScopeW(r_d3d11_state->device_rw_mutex)
   {
-    R_D3D11_Tex2D *texture = r_d3d11_tex2d_from_handle(handle);
-    if(texture != &r_d3d11_tex2d_nil)
-    {
-      SLLStackPush(r_d3d11_state->first_to_free_tex2d, texture);
-    }
+    R_D3D11_Tex2D *texture = r_d3d11_tex2d_from_handle(handle);
+    if(texture != &r_d3d11_tex2d_nil)
+    {
+      SLLStackPush(r_d3d11_state->first_to_free_tex2d, texture);
+    }
   }
   ProfEnd();
 }
@@ -705,19 +705,19 @@ r_fill_tex2d_region(R_Handle handle, Rng2S32 subrect, void *data)
   ProfBeginFunction();
   OS_MutexScopeW(r_d3d11_state->device_rw_mutex)
   {
-    R_D3D11_Tex2D *texture = r_d3d11_tex2d_from_handle(handle);
-    if(texture != &r_d3d11_tex2d_nil)
-    {
+    R_D3D11_Tex2D *texture = r_d3d11_tex2d_from_handle(handle);
+    if(texture != &r_d3d11_tex2d_nil)
+    {
       Assert(texture->kind == R_ResourceKind_Dynamic && "only dynamic texture can update region");
       U64 bytes_per_pixel = r_tex2d_format_bytes_per_pixel_table[texture->format];
-      Vec2S32 dim = v2s32(subrect.x1 - subrect.x0, subrect.y1 - subrect.y0);
+      Vec2S32 dim = v2s32(subrect.x1 - subrect.x0, subrect.y1 - subrect.y0);
       D3D11_BOX dst_box =
       {
         (UINT)subrect.x0, (UINT)subrect.y0, 0,
         (UINT)subrect.x1, (UINT)subrect.y1, 1,
       };
-      r_d3d11_state->device_ctx->lpVtbl->UpdateSubresource(r_d3d11_state->device_ctx, (ID3D11Resource *)texture->texture, 0, &dst_box, data, dim.x*bytes_per_pixel, 0);
-    }
+      r_d3d11_state->device_ctx->lpVtbl->UpdateSubresource(r_d3d11_state->device_ctx, (ID3D11Resource *)texture->texture, 0, &dst_box, data, dim.x*bytes_per_pixel, 0);
+    }
   }
   ProfEnd();
 }
@@ -823,10 +823,10 @@ r_end_frame(void)
         tex = next)
     {
       next = tex->next;
-      tex->view->lpVtbl->Release(tex->view);
-      tex->texture->lpVtbl->Release(tex->texture);
-      tex->view = 0;
-      tex->texture = 0;
+      tex->view->lpVtbl->Release(tex->view);
+      tex->texture->lpVtbl->Release(tex->texture);
+      tex->view = 0;
+      tex->texture = 0;
       tex->generation += 1;
       SLLStackPush(r_d3d11_state->first_free_tex2d, tex);
     }
@@ -1119,29 +1119,14 @@ r_window_submit(OS_Handle window, R_Handle window_equip, R_PassList *passes)
             R_D3D11_Tex2D *texture = r_d3d11_tex2d_from_handle(texture_handle);
             
             // rjf: get texture sample map matrix, based on format
-            Vec4F32 texture_sample_channel_map[] =
-            {
-              {1, 0, 0, 0},
-              {0, 1, 0, 0},
-              {0, 0, 1, 0},
-              {0, 0, 0, 1},
-            };
-            switch(texture->format)
-            {
-              default: break;
-              case R_Tex2DFormat_R8:
-              {
-                MemoryZeroArray(texture_sample_channel_map);
-                texture_sample_channel_map[0] = v4f32(1, 1, 1, 1);
-              }break;
-            }
+            Mat4x4F32 texture_sample_channel_map = r_sample_channel_map_from_tex2dformat(texture->format);
             
             // rjf: upload uniforms
             R_D3D11_Uniforms_Rect uniforms = {0};
             {
               uniforms.viewport_size             = v2f32(resolution.x, resolution.y);
               uniforms.opacity                   = 1-group_params->transparency;
-              MemoryCopyArray(uniforms.texture_sample_channel_map, texture_sample_channel_map);
+              uniforms.texture_sample_channel_map = texture_sample_channel_map;
               uniforms.texture_t2d_size          = v2f32(texture->size.x, texture->size.y);
               uniforms.xform[0] = v4f32(group_params->xform.v[0][0], group_params->xform.v[1][0], group_params->xform.v[2][0], 0);
               uniforms.xform[1] = v4f32(group_params->xform.v[0][1], group_params->xform.v[1][1], group_params->xform.v[2][1], 0);
diff --git a/src/render/d3d11/render_d3d11.h b/src/render/d3d11/render_d3d11.h
index aba28899..b1b0d5fd 100644
--- a/src/render/d3d11/render_d3d11.h
+++ b/src/render/d3d11/render_d3d11.h
@@ -29,7 +29,7 @@ struct R_D3D11_Uniforms_Rect
   Vec2F32 viewport_size;
   F32 opacity;
   F32 _padding0_;
-  Vec4F32 texture_sample_channel_map[4];
+  Mat4x4F32 texture_sample_channel_map;
   Vec2F32 texture_t2d_size;
   Vec2F32 translate;
   Vec4F32 xform[3];
diff --git a/src/render/d3d11/render_d3d11.mdesk b/src/render/d3d11/render_d3d11.mdesk
index 1c78b56b..81e2084d 100644
--- a/src/render/d3d11/render_d3d11.mdesk
+++ b/src/render/d3d11/render_d3d11.mdesk
@@ -277,8 +277,7 @@ vs_main(CPU2Vertex c2v)
     corner_radii_px.w,
     corner_radii_px.z,
   };
-  float2 cornercoords__pct = float2(
-                                    (c2v.vertex_id >> 1) ? 1.f : 0.f,
+  float2 cornercoords__pct = float2((c2v.vertex_id >> 1) ? 1.f : 0.f,
                                     (c2v.vertex_id & 1)  ? 0.f : 1.f);
   
   float2 vertex_position__pct = vertex_positions__scrn[c2v.vertex_id] / viewport_size;
diff --git a/src/render/opengl/generated/render_opengl.meta.c b/src/render/opengl/generated/render_opengl.meta.c
new file mode 100644
index 00000000..60c10194
--- /dev/null
+++ b/src/render/opengl/generated/render_opengl.meta.c
@@ -0,0 +1,38 @@
+// Copyright (c) 2024 Epic Games Tools
+// Licensed under the MIT license (https://opensource.org/license/mit/)
+
+//- GENERATED CODE
+
+C_LINKAGE_BEGIN
+String8 r_ogl_shader_kind_name_table[2] =
+{
+str8_lit_comp("rect"),
+str8_lit_comp("blur"),
+};
+
+String8 * r_ogl_shader_kind_vshad_src_table[2] =
+{
+&r_ogl_rect_vshad_src,
+&r_ogl_blur_vshad_src,
+};
+
+String8 * r_ogl_shader_kind_pshad_src_table[2] =
+{
+&r_ogl_rect_pshad_src,
+&r_ogl_blur_pshad_src,
+};
+
+R_OGL_AttributeArray r_ogl_shader_kind_input_attributes_table[2] =
+{
+{ r_ogl_rect_input_attributes, ArrayCount(r_ogl_rect_input_attributes) },
+{ 0,  },
+};
+
+R_OGL_AttributeArray r_ogl_shader_kind_output_attributes_table[2] =
+{
+{ r_ogl_single_color_output_attributes, ArrayCount(r_ogl_single_color_output_attributes) },
+{ r_ogl_single_color_output_attributes, ArrayCount(r_ogl_single_color_output_attributes) },
+};
+
+C_LINKAGE_END
+
diff --git a/src/render/opengl/generated/render_opengl.meta.h b/src/render/opengl/generated/render_opengl.meta.h
new file mode 100644
index 00000000..6e7f6024
--- /dev/null
+++ b/src/render/opengl/generated/render_opengl.meta.h
@@ -0,0 +1,276 @@
+// Copyright (c) 2024 Epic Games Tools
+// Licensed under the MIT license (https://opensource.org/license/mit/)
+
+//- GENERATED CODE
+
+#ifndef RENDER_OPENGL_META_H
+#define RENDER_OPENGL_META_H
+
+typedef enum R_OGL_ShaderKind
+{
+R_OGL_ShaderKind_Rect,
+R_OGL_ShaderKind_Blur,
+R_OGL_ShaderKind_COUNT,
+} R_OGL_ShaderKind;
+
+C_LINKAGE_BEGIN
+extern String8 r_ogl_shader_kind_name_table[2];
+extern String8 * r_ogl_shader_kind_vshad_src_table[2];
+extern String8 * r_ogl_shader_kind_pshad_src_table[2];
+extern R_OGL_AttributeArray r_ogl_shader_kind_input_attributes_table[2];
+extern R_OGL_AttributeArray r_ogl_shader_kind_output_attributes_table[2];
+read_only global String8 r_ogl_rect_vshad_src =
+str8_lit_comp(
+""
+"\n"
+"#version 330 core\n"
+"\n"
+"in vec4 c2v_dst_rect;\n"
+"in vec4 c2v_src_rect;\n"
+"in vec4 c2v_colors_0;\n"
+"in vec4 c2v_colors_1;\n"
+"in vec4 c2v_colors_2;\n"
+"in vec4 c2v_colors_3;\n"
+"in vec4 c2v_corner_radii;\n"
+"in vec4 c2v_style;  // x: border_thickness_px, y: softness_px, z: omit_texture, w: unused\n"
+"\n"
+"out vec2 v2p_sdf_sample_pos;\n"
+"out vec2 v2p_texcoord_pct;\n"
+"out vec2 v2p_rect_half_size_px;\n"
+"out vec4 v2p_tint;\n"
+"out float v2p_corner_radius;\n"
+"out float v2p_border_thickness;\n"
+"out float v2p_softness;\n"
+"out float v2p_omit_texture;\n"
+"\n"
+"uniform sampler2D u_tex_color;\n"
+"uniform vec2 u_viewport_size_px;\n"
+"\n"
+"void main(void)\n"
+"{\n"
+"  // rjf: constants\n"
+"  vec2 vertices[] = vec2[](vec2(-1, -1), vec2(-1, +1), vec2(+1, -1), vec2(+1, +1));\n"
+"  \n"
+"  // rjf: find dst position\n"
+"  vec2 dst_half_size = (c2v_dst_rect.zw - c2v_dst_rect.xy) / 2;\n"
+"  vec2 dst_center    = (c2v_dst_rect.zw + c2v_dst_rect.xy) / 2;\n"
+"  vec2 dst_position  = vertices[gl_VertexID] * dst_half_size + dst_center;\n"
+"  \n"
+"  // rjf: find src position\n"
+"  vec2 src_half_size = (c2v_src_rect.zw - c2v_src_rect.xy) / 2;\n"
+"  vec2 src_center    = (c2v_src_rect.zw + c2v_src_rect.xy) / 2;\n"
+"  vec2 src_position  = vertices[gl_VertexID] * src_half_size + src_center;\n"
+"  \n"
+"  // rjf: find color\n"
+"  vec4 colors[] = vec4[](c2v_colors_0, c2v_colors_1, c2v_colors_2, c2v_colors_3);\n"
+"  vec4 color = colors[gl_VertexID];\n"
+"  \n"
+"  // rjf: find corner radius\n"
+"  float corner_radii[] = float[](c2v_corner_radii.x, c2v_corner_radii.y, c2v_corner_radii.z, c2v_corner_radii.w);\n"
+"  float corner_radius = corner_radii[gl_VertexID];\n"
+"  \n"
+"  // rjf: fill outputs\n"
+"  vec2 dst_verts_pct = vec2(((gl_VertexID >> 1) != 1) ? 1.f : 0.f,\n"
+"                            ((gl_VertexID & 1) != 0)  ? 0.f : 1.f);\n"
+"  ivec2 u_tex_color_size_i = textureSize(u_tex_color, 0);\n"
+"  vec2 u_tex_color_size = vec2(float(u_tex_color_size_i.x), float(u_tex_color_size_i.y));\n"
+"  {\n"
+"    gl_Position = vec4(2 * dst_position.x / u_viewport_size_px.x - 1,\n"
+"                       2 * (1 - dst_position.y / u_viewport_size_px.y) - 1,\n"
+"                       0.0, 1.0);\n"
+"    v2p_sdf_sample_pos    = (2.f * dst_verts_pct - 1.f) * dst_half_size;\n"
+"    v2p_texcoord_pct      = src_position / u_tex_color_size;\n"
+"    v2p_rect_half_size_px = dst_half_size;\n"
+"    v2p_tint              = color;\n"
+"    v2p_corner_radius     = corner_radius;\n"
+"    v2p_border_thickness  = c2v_style.x;\n"
+"    v2p_softness          = c2v_style.y;\n"
+"    v2p_omit_texture      = c2v_style.z;\n"
+"  }\n"
+"}\n"
+""
+);
+
+read_only global String8 r_ogl_rect_pshad_src =
+str8_lit_comp(
+""
+"\n"
+"#version 330 core\n"
+"\n"
+"in vec2 v2p_sdf_sample_pos;\n"
+"in vec2 v2p_texcoord_pct;\n"
+"in vec2 v2p_rect_half_size_px;\n"
+"in vec4 v2p_tint;\n"
+"in float v2p_corner_radius;\n"
+"in float v2p_border_thickness;\n"
+"in float v2p_softness;\n"
+"in float v2p_omit_texture;\n"
+"\n"
+"out vec4 final_color;\n"
+"\n"
+"uniform float u_opacity;\n"
+"uniform sampler2D u_tex_color;\n"
+"uniform mat4 u_texture_sample_channel_map;\n"
+"\n"
+"float rect_sdf(vec2 sample_pos, vec2 rect_half_size, float r)\n"
+"{\n"
+"  return length(max(abs(sample_pos) - rect_half_size + r, 0.0)) - r;\n"
+"}\n"
+"\n"
+"float linear_from_srgb_f32(float x)\n"
+"{\n"
+"  return x < 0.0404482362771082 ? x / 12.92 : pow((x + 0.055) / 1.055, 2.4);\n"
+"}\n"
+"\n"
+"vec4 linear_from_srgba(vec4 v)\n"
+"{\n"
+"  vec4 result = vec4(linear_from_srgb_f32(v.x),\n"
+"                     linear_from_srgb_f32(v.y),\n"
+"                     linear_from_srgb_f32(v.z),\n"
+"                     v.w);\n"
+"  return result;\n"
+"}\n"
+"\n"
+"void main(void)\n"
+"{\n"
+"  // rjf: sample texture\n"
+"  vec4 albedo_sample = vec4(1, 1, 1, 1);\n"
+"  if(v2p_omit_texture < 1)\n"
+"  {\n"
+"    albedo_sample = u_texture_sample_channel_map * texture(u_tex_color, v2p_texcoord_pct);\n"
+"    albedo_sample = linear_from_srgba(albedo_sample);\n"
+"  }\n"
+"  \n"
+"  // rjf: sample for borders\n"
+"  float border_sdf_t = 1;\n"
+"  if(v2p_border_thickness > 0)\n"
+"  {\n"
+"    float border_sdf_s = rect_sdf(v2p_sdf_sample_pos,\n"
+"                                  v2p_rect_half_size_px - vec2(v2p_softness*2.f, v2p_softness*2.f) - v2p_border_thickness,\n"
+"                                  max(v2p_corner_radius-v2p_border_thickness, 0));\n"
+"    border_sdf_t = smoothstep(0, 2*v2p_softness, border_sdf_s);\n"
+"  }\n"
+"  if(border_sdf_t < 0.001f)\n"
+"  {\n"
+"    discard;\n"
+"  }\n"
+"  \n"
+"  // rjf: sample for corners\n"
+"  float corner_sdf_t = 1;\n"
+"  if(v2p_corner_radius > 0 || v2p_softness > 0.75f)\n"
+"  {\n"
+"    float corner_sdf_s = rect_sdf(v2p_sdf_sample_pos,\n"
+"                                  v2p_rect_half_size_px - vec2(v2p_softness*2.f, v2p_softness*2.f),\n"
+"                                  v2p_corner_radius);\n"
+"    corner_sdf_t = 1-smoothstep(0, 2*v2p_softness, corner_sdf_s);\n"
+"  }\n"
+"  \n"
+"  // rjf: form+return final color\n"
+"  final_color = albedo_sample;\n"
+"  final_color *= v2p_tint;\n"
+"  final_color.a *= u_opacity;\n"
+"  final_color.a *= corner_sdf_t;\n"
+"  final_color.a *= border_sdf_t;\n"
+"}\n"
+""
+);
+
+read_only global String8 r_ogl_blur_vshad_src =
+str8_lit_comp(
+""
+"\n"
+"#version 330 core\n"
+"\n"
+"uniform vec4 rect;\n"
+"uniform vec4 corner_radii_px;\n"
+"uniform vec2 viewport_size;\n"
+"uniform uint blur_count;\n"
+"\n"
+"out vec2 texcoord;\n"
+"out vec2 sdf_sample_pos;\n"
+"out vec2 rect_half_size;\n"
+"out float corner_radius;\n"
+"\n"
+"void main(void)\n"
+"{\n"
+"  vec2 vertex_positions_scrn[] = vec2[](rect.xw,\n"
+"                                        rect.xy,\n"
+"                                        rect.zw,\n"
+"                                        rect.zy);\n"
+"  float corner_radii_px[] = float[](corner_radii_px.y,\n"
+"                                    corner_radii_px.x,\n"
+"                                    corner_radii_px.w,\n"
+"                                    corner_radii_px.z);\n"
+"  vec2 cornercoords_pct = vec2((gl_VertexID >> 1) != 0 ? 1.f : 0.f,\n"
+"                               (gl_VertexID & 1) != 0  ? 0.f : 1.f);\n"
+"  \n"
+"  vec2 vertex_position_pct = vertex_positions_scrn[gl_VertexID] / viewport_size;\n"
+"  vec2 vertex_position_scr = 2.f * vertex_position_pct - 1.f;\n"
+"  \n"
+"  vec2 rect_half_size = vec2((rect.z-rect.x)/2, (rect.w-rect.y)/2);\n"
+"  \n"
+"  gl_Position = vec4(vertex_position_scr.x, -vertex_position_scr.y, 0.f, 1.f);\n"
+"  texcoord = vertex_position_pct;\n"
+"  sdf_sample_pos = (2.f * cornercoords_pct - 1.f) * rect_half_size;\n"
+"  rect_half_size = rect_half_size - 2.f;\n"
+"  corner_radius = corner_radii_px[gl_VertexID];\n"
+"}\n"
+""
+);
+
+read_only global String8 r_ogl_blur_pshad_src =
+str8_lit_comp(
+""
+"\n"
+"#version 330 core\n"
+"\n"
+"uniform sampler2D tex;\n"
+"uniform vec4 kernel[32];\n"
+"uniform int blur_count;\n"
+"uniform vec2 direction;\n"
+"\n"
+"in vec2 texcoord;\n"
+"in vec2 sdf_sample_pos;\n"
+"in vec2 rect_half_size;\n"
+"in float corner_radius;\n"
+"\n"
+"out vec4 final_color;\n"
+"\n"
+"float rect_sdf(vec2 sample_pos, vec2 rect_half_size, float r)\n"
+"{\n"
+"  return length(max(abs(sample_pos) - rect_half_size + r, 0.0)) - r;\n"
+"}\n"
+"\n"
+"void main(void)\n"
+"{\n"
+"  // rjf: blend weighted texture samples into color\n"
+"  vec3 color = kernel[0].x * texture(tex, texcoord).rgb;\n"
+"  \n"
+"  for(int i = 1; i < blur_count; i += 1)\n"
+"  {\n"
+"    float weight = kernel[i].x;\n"
+"    float offset = kernel[i].y;\n"
+"    color += weight * texture(tex, texcoord - offset * direction).rgb;\n"
+"    color += weight * texture(tex, texcoord + offset * direction).rgb;\n"
+"  }\n"
+"  \n"
+"  // rjf: sample for corners\n"
+"  float corner_sdf_s = rect_sdf(sdf_sample_pos, rect_half_size, corner_radius);\n"
+"  float corner_sdf_t = 1-smoothstep(0, 2, corner_sdf_s);\n"
+"  \n"
+"  // rjf: weight output color by sdf\n"
+"  // this is doing alpha testing, leave blurring only where mostly opaque pixels are\n"
+"  if(corner_sdf_t < 0.9f)\n"
+"  {\n"
+"    discard;\n"
+"  }\n"
+"  \n"
+"  final_color = vec4(color, 1.f);\n"
+"}\n"
+""
+);
+
+
+C_LINKAGE_END
+
+#endif // RENDER_OPENGL_META_H
diff --git a/src/render/opengl/render_opengl.c b/src/render/opengl/render_opengl.c
new file mode 100644
index 00000000..cfbec7de
--- /dev/null
+++ b/src/render/opengl/render_opengl.c
@@ -0,0 +1,480 @@
+// Copyright (c) 2024 Epic Games Tools
+// Licensed under the MIT license (https://opensource.org/license/mit/)
+
+////////////////////////////////
+//~ rjf: OS Portion Includes
+
+#if OS_WINDOWS
+# include "render/opengl/win32/render_opengl_win32.c"
+#else
+# error OS portion of OpenGL rendering backend not defined.
+#endif
+
+////////////////////////////////
+//~ rjf: Attribute Tables
+
+global read_only R_OGL_Attribute r_ogl_rect_input_attributes[] =
+{
+  {0, str8_lit_comp("c2v_dst_rect"),        GL_FLOAT,  4},
+  {1, str8_lit_comp("c2v_src_rect"),        GL_FLOAT,  4},
+  {2, str8_lit_comp("c2v_colors_0"),        GL_FLOAT,  4},
+  {3, str8_lit_comp("c2v_colors_1"),        GL_FLOAT,  4},
+  {4, str8_lit_comp("c2v_colors_2"),        GL_FLOAT,  4},
+  {5, str8_lit_comp("c2v_colors_3"),        GL_FLOAT,  4},
+  {6, str8_lit_comp("c2v_corner_radii"),    GL_FLOAT,  4},
+  {7, str8_lit_comp("c2v_style"),           GL_FLOAT,  4},
+};
+
+global read_only R_OGL_Attribute r_ogl_single_color_output_attributes[] =
+{
+  {0, str8_lit_comp("final_color")},
+};
+
+////////////////////////////////
+//~ rjf: Generated Code
+
+#include "render/opengl/generated/render_opengl.meta.c"
+
+////////////////////////////////
+//~ rjf: Helpers
+
+internal R_Handle
+r_ogl_handle_from_tex2d(R_OGL_Tex2D *t)
+{
+  R_Handle h = {(U64)t};
+  return h;
+}
+
+internal R_OGL_Tex2D *
+r_ogl_tex2d_from_handle(R_Handle h)
+{
+  R_OGL_Tex2D *t = (R_OGL_Tex2D *)h.u64[0];
+  return t;
+}
+
+internal R_OGL_FormatInfo
+r_ogl_format_info_from_tex2dformat(R_Tex2DFormat fmt)
+{
+  R_OGL_FormatInfo result;
+  result.internal_format = GL_RGBA;
+  result.format = GL_RGBA;
+  result.base_type = GL_UNSIGNED_BYTE;
+  // TODO(rjf)
+  return result;
+}
+
+internal void
+r_ogl_debug_message_callback(GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, const GLchar *message, const void *userParam)
+{
+  raddbg_log("[OpenGL] %.*s\n", (int)length, message);
+}
+
+////////////////////////////////
+//~ rjf: Backend Hooks
+
+//- rjf: top-level layer initialization
+
+r_hook void
+r_init(CmdLine *cmdln)
+{
+  //- rjf: do os-specific portion of work
+  r_ogl_os_init(cmdln);
+  
+  //- rjf: top-level initialization
+  Arena *arena = arena_alloc();
+  r_ogl_state = push_array(arena, R_OGL_State, 1);
+  r_ogl_state->arena = arena;
+  
+  //- rjf: load gl procedures
+#define X(name, r, p) name = (name##_FunctionType *)r_ogl_os_load_procedure(#name);
+  R_OGL_ProcedureXList
+#undef X
+  
+  //- rjf: build all shaders
+  for EachEnumVal(R_OGL_ShaderKind, k)
+  {
+    // rjf: compile
+    struct {GLenum type; String8 *src; GLuint out; String8 errors;} stages[] =
+    {
+      {GL_VERTEX_SHADER,   r_ogl_shader_kind_vshad_src_table[k]},
+      {GL_FRAGMENT_SHADER, r_ogl_shader_kind_pshad_src_table[k]},
+    };
+    for EachElement(idx, stages)
+    {
+      stages[idx].out = glCreateShader(stages[idx].type);
+      GLint src_size = stages[idx].src->size;
+      glShaderSource(stages[idx].out, 1, &stages[idx].src->str, &src_size);
+      glCompileShader(stages[idx].out);
+      GLint info_log_length = 0;
+      GLint status = 0;
+      glGetShaderiv(stages[idx].out, GL_COMPILE_STATUS, &status);
+      glGetShaderiv(stages[idx].out, GL_INFO_LOG_LENGTH, &info_log_length);
+      if(info_log_length != 0)
+      {
+        stages[idx].errors.str = push_array(r_ogl_state->arena, U8, info_log_length+1);
+        stages[idx].errors.size = info_log_length;
+        glGetShaderInfoLog(stages[idx].out, info_log_length, 0, stages[idx].errors.str);
+      }
+      raddbg_pin(text(stages[idx].errors.str));
+    }
+    
+    // rjf: attach compilations to program
+    GLuint program = glCreateProgram();
+    for EachElement(idx, stages)
+    {
+      glAttachShader(program, stages[idx].out);
+    }
+    
+    // rjf: bind inputs
+    R_OGL_AttributeArray inputs = r_ogl_shader_kind_input_attributes_table[k];
+    for EachIndex(idx, inputs.count)
+    {
+      glBindAttribLocation(program, inputs.v[idx].index, inputs.v[idx].name.str);
+    }
+    
+    // rjf: bind outputs
+    R_OGL_AttributeArray outputs = r_ogl_shader_kind_output_attributes_table[k];
+    for EachIndex(idx, outputs.count)
+    {
+      glBindFragDataLocation(program, outputs.v[idx].index, outputs.v[idx].name.str);
+    }
+    
+    // rjf: link / validate / store
+    glLinkProgram(program);
+    glValidateProgram(program);
+    r_ogl_state->shaders[k] = program;
+  }
+  
+  //- rjf: set up built-in resources
+  glGenVertexArrays(1, &r_ogl_state->all_purpose_vao);
+  glGenBuffers(1, &r_ogl_state->scratch_buffer_2mb);
+  glBindBuffer(GL_ARRAY_BUFFER, r_ogl_state->scratch_buffer_2mb);
+  glBufferData(GL_ARRAY_BUFFER, MB(2), 0, GL_DYNAMIC_DRAW);
+  glBindBuffer(GL_ARRAY_BUFFER, 0);
+  glGenTextures(1, &r_ogl_state->white_texture);
+  glBindTexture(GL_TEXTURE_2D, r_ogl_state->white_texture);
+  U32 white_pixel = 0xffffffff;
+  glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, &white_pixel);
+  glEnable(GL_FRAMEBUFFER_SRGB);
+  
+  //- rjf: set up debug callback
+  glEnable(GL_DEBUG_OUTPUT);
+  glDebugMessageCallback(r_ogl_debug_message_callback, 0);
+}
+
+//- rjf: window setup/teardown
+
+r_hook R_Handle
+r_window_equip(OS_Handle window)
+{
+  R_Handle result = r_ogl_os_window_equip(window);
+  return result;
+}
+
+r_hook void
+r_window_unequip(OS_Handle window, R_Handle window_equip)
+{
+  r_ogl_os_window_unequip(window, window_equip);
+}
+
+//- rjf: textures
+
+r_hook R_Handle
+r_tex2d_alloc(R_ResourceKind kind, Vec2S32 size, R_Tex2DFormat format, void *data)
+{
+  //- rjf: allocate texture record
+  R_OGL_Tex2D *tex2d = r_ogl_state->free_tex2d;
+  if(tex2d)
+  {
+    SLLStackPop(r_ogl_state->free_tex2d);
+  }
+  else
+  {
+    tex2d = push_array(r_ogl_state->arena, R_OGL_Tex2D, 1);
+  }
+  
+  //- rjf: map kind/format -> gl counterparts
+  R_OGL_FormatInfo gl_fmt_info = r_ogl_format_info_from_tex2dformat(format);
+  
+  //- rjf: allocate GL texture
+  {
+    glGenTextures(1, &tex2d->id);
+    glBindTexture(GL_TEXTURE_2D, tex2d->id);
+    glTexImage2D(GL_TEXTURE_2D, 0, gl_fmt_info.internal_format, size.x, size.y, 0, gl_fmt_info.format, gl_fmt_info.base_type, data);
+    glBindTexture(GL_TEXTURE_2D, 0);
+  }
+  
+  //- rjf: fill
+  tex2d->resource_kind = kind;
+  tex2d->fmt = format;
+  tex2d->size = size;
+  
+  //- rjf: bundle & return
+  R_Handle result = r_ogl_handle_from_tex2d(tex2d);
+  return result;
+}
+
+r_hook void
+r_tex2d_release(R_Handle texture)
+{
+  R_OGL_Tex2D *t = r_ogl_tex2d_from_handle(texture);
+  if(t != 0)
+  {
+    glDeleteTextures(1, &t->id);
+    SLLStackPush(r_ogl_state->free_tex2d, t);
+  }
+}
+
+r_hook R_ResourceKind
+r_kind_from_tex2d(R_Handle texture)
+{
+  R_ResourceKind result = R_ResourceKind_Static;
+  R_OGL_Tex2D *t = r_ogl_tex2d_from_handle(texture);
+  if(t)
+  {
+    result = t->resource_kind;
+  }
+  return result;
+}
+
+r_hook Vec2S32
+r_size_from_tex2d(R_Handle texture)
+{
+  Vec2S32 result = {0, 0};
+  R_OGL_Tex2D *t = r_ogl_tex2d_from_handle(texture);
+  if(t)
+  {
+    result = t->size;
+  }
+  return result;
+}
+
+r_hook R_Tex2DFormat
+r_format_from_tex2d(R_Handle texture)
+{
+  R_Tex2DFormat result = R_Tex2DFormat_RGBA8;
+  R_OGL_Tex2D *t = r_ogl_tex2d_from_handle(texture);
+  if(t)
+  {
+    result = t->fmt;
+  }
+  return result;
+}
+
+r_hook void
+r_fill_tex2d_region(R_Handle texture, Rng2S32 subrect, void *data)
+{
+  R_OGL_Tex2D *t = r_ogl_tex2d_from_handle(texture);
+  if(t)
+  {
+    R_OGL_FormatInfo fmt_info = r_ogl_format_info_from_tex2dformat(t->fmt);
+    glBindTexture(GL_TEXTURE_2D, t->id);
+    Vec2S32 rect_size = dim_2s32(subrect);
+    glTexSubImage2D(GL_TEXTURE_2D, 0, subrect.x0, subrect.y0, rect_size.x, rect_size.y, fmt_info.format, fmt_info.base_type, data);
+    glBindTexture(GL_TEXTURE_2D, 0);
+  }
+}
+
+//- rjf: buffers
+
+r_hook R_Handle
+r_buffer_alloc(R_ResourceKind kind, U64 size, void *data)
+{
+  R_Handle result = {0};
+  return result;
+}
+
+r_hook void
+r_buffer_release(R_Handle buffer)
+{
+  // TODO(rjf)
+}
+
+//- rjf: frame markers
+
+r_hook void
+r_begin_frame(void)
+{
+  // TODO(rjf)
+}
+
+r_hook void
+r_end_frame(void)
+{
+  // TODO(rjf)
+}
+
+r_hook void
+r_window_begin_frame(OS_Handle os, R_Handle r)
+{
+  r_ogl_os_select_window(os, r);
+  
+  //- rjf: unpack window viewport info
+  Rng2F32 client_rect = os_client_rect_from_window(os);
+  Vec2F32 client_rect_dim = dim_2f32(client_rect);
+  
+  //- rjf: clear and reset state
+  glClearColor(0, 0, 0, 0);
+  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+  glViewport(0, 0, (S32)client_rect_dim.x, (S32)client_rect_dim.y);
+  glEnable(GL_BLEND);
+  glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+}
+
+r_hook void
+r_window_end_frame(OS_Handle os, R_Handle r)
+{
+  r_ogl_os_window_swap(os, r);
+}
+
+//- rjf: render pass submission
+
+r_hook void
+r_window_submit(OS_Handle window, R_Handle window_equip, R_PassList *passes)
+{
+  Rng2F32 viewport_rect = os_client_rect_from_window(window);
+  Vec2F32 viewport_dim = dim_2f32(viewport_rect);
+  for(R_PassNode *pass_n = passes->first; pass_n != 0; pass_n = pass_n->next)
+  {
+    R_Pass *pass = &pass_n->v;
+    switch(pass->kind)
+    {
+      default:{}break;
+      
+      ////////////////////////
+      //- rjf: ui rendering pass
+      //
+      case R_PassKind_UI:
+      {
+        //- rjf: unpack params
+        R_PassParams_UI *params = pass->params_ui;
+        R_BatchGroup2DList *rect_batch_groups = &params->rects;
+        
+        //- rjf: draw each batch group
+        GLuint shader = r_ogl_state->shaders[R_OGL_ShaderKind_Rect];
+        glBindVertexArrayScope(r_ogl_state->all_purpose_vao) glUseProgramScope(shader)
+        {
+          for(R_BatchGroup2DNode *group_n = rect_batch_groups->first; group_n != 0; group_n = group_n->next)
+          {
+            R_BatchList *batches = &group_n->batches;
+            R_BatchGroup2DParams *group_params = &group_n->params;
+            
+            //- rjf: unpack texture
+            R_Tex2DFormat texture_fmt = R_Tex2DFormat_RGBA8;
+            GLuint texture_id = r_ogl_state->white_texture;
+            {
+              R_OGL_Tex2D *tex = r_ogl_tex2d_from_handle(group_params->tex);
+              if(tex != 0)
+              {
+                texture_id = tex->id;
+                texture_fmt = tex->fmt;
+              }
+            }
+            
+            //- rjf: get & fill buffer
+            GLuint buffer = r_ogl_state->scratch_buffer_2mb; // TODO(rjf): r_ogl_instance_buffer_from_size(batches->byte_count);
+            {
+              glBindBuffer(GL_ARRAY_BUFFER, buffer);
+              U64 off = 0;
+              for(R_BatchNode *batch_n = batches->first; batch_n != 0; batch_n = batch_n->next)
+              {
+                glBufferSubData(GL_ARRAY_BUFFER, off, batch_n->v.byte_count, batch_n->v.v);
+                off += batch_n->v.byte_count;
+              }
+            }
+            
+            //- rjf: bind input attributes
+            {
+              R_OGL_AttributeArray inputs = r_ogl_shader_kind_input_attributes_table[R_OGL_ShaderKind_Rect];
+              U64 off = 0;
+              for EachIndex(idx, inputs.count)
+              {
+                glEnableVertexAttribArray(inputs.v[idx].index);
+                glVertexAttribDivisor(inputs.v[idx].index, 1);
+                glVertexAttribPointer(inputs.v[idx].index, inputs.v[idx].count, inputs.v[idx].type, GL_FALSE, sizeof(R_Rect2DInst), (void *)(off));
+                // TODO(rjf): this is not correct if type != GL_FLOAT
+                off += inputs.v[idx].count*sizeof(F32);
+              }
+            }
+            
+            //- rjf: bind texture
+            {
+              glActiveTexture(GL_TEXTURE0);
+              glBindTexture(GL_TEXTURE_2D, texture_id);
+              glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+              glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+              switch(group_params->tex_sample_kind)
+              {
+                default:
+                case R_Tex2DSampleKind_Nearest:
+                {
+                  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+                  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+                }break;
+                case R_Tex2DSampleKind_Linear:
+                {
+                  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+                  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+                }break;
+              }
+              glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, 0);
+              glUniform1i(glGetUniformLocation(shader, "u_tex_color"), 0);
+            }
+            
+            //- rjf: upload misc. uniforms
+            {
+              Mat4x4F32 texture_sample_channel_map = r_sample_channel_map_from_tex2dformat(texture_fmt);
+              glUniformMatrix4fv(glGetUniformLocation(shader, "u_texture_sample_channel_map"), 1, 0, &texture_sample_channel_map.v[0][0]);
+              glUniform2f(glGetUniformLocation(shader, "u_viewport_size_px"), viewport_dim.x, viewport_dim.y);
+              glUniform1f(glGetUniformLocation(shader, "u_opacity"), 1.f - group_params->transparency);
+            }
+            
+            //- rjf: set up scissor
+            if(group_params->clip.x0 != 0 ||
+               group_params->clip.x1 != 0 ||
+               group_params->clip.y0 != 0 ||
+               group_params->clip.y1 != 0)
+            {
+              Rng2F32 clip = group_params->clip;
+              glScissor(clip.x0, viewport_dim.y - clip.y1, (clip.x1-clip.x0) + 1, (clip.y1-clip.y0)+1);
+              glEnable(GL_SCISSOR_TEST);
+            }
+            
+            //- rjf: draw
+            {
+              glDrawArraysInstanced(GL_TRIANGLE_STRIP, 0, 4, batches->byte_count / batches->bytes_per_inst);
+            }
+            
+            //- rjf: unset scissor
+            glDisable(GL_SCISSOR_TEST);
+          }
+        }
+      }break;
+      
+      ////////////////////////
+      //- rjf: blur rendering pass
+      //
+      case R_PassKind_Blur:
+      {
+        R_PassParams_Blur *params = pass->params_blur;
+        GLuint shader = r_ogl_state->shaders[R_OGL_ShaderKind_Blur];
+        glBindVertexArrayScope(r_ogl_state->all_purpose_vao) glUseProgramScope(shader)
+        {
+          // TODO(rjf)
+        }
+      }break;
+      
+      
+      ////////////////////////
+      //- rjf: 3d geometry rendering pass
+      //
+      case R_PassKind_Geo3D:
+      {
+        //- rjf: unpack params
+        R_PassParams_Geo3D *params = pass->params_geo3d;
+        R_BatchGroup3DMap *mesh_group_map = &params->mesh_batches;
+        // TODO(rjf)
+      }break;
+    }
+  }
+}
diff --git a/src/render/opengl/render_opengl.h b/src/render/opengl/render_opengl.h
new file mode 100644
index 00000000..39ee5b5d
--- /dev/null
+++ b/src/render/opengl/render_opengl.h
@@ -0,0 +1,217 @@
+// Copyright (c) 2024 Epic Games Tools
+// Licensed under the MIT license (https://opensource.org/license/mit/)
+
+#ifndef RENDER_OPENGL_H
+#define RENDER_OPENGL_H
+
+////////////////////////////////
+//~ rjf: OS Backend Includes
+
+#if OS_WINDOWS
+# include "render/opengl/win32/render_opengl_win32.h"
+#else
+# error OS portion of OpenGL rendering backend not defined.
+#endif
+
+////////////////////////////////
+//~ rjf: Shader Metadata Types
+
+typedef struct R_OGL_Attribute R_OGL_Attribute;
+struct R_OGL_Attribute
+{
+  U64 index;
+  String8 name;
+  GLenum type;
+  U64 count;
+};
+
+typedef struct R_OGL_AttributeArray R_OGL_AttributeArray;
+struct R_OGL_AttributeArray
+{
+  R_OGL_Attribute *v;
+  U64 count;
+};
+
+////////////////////////////////
+//~ rjf: Generated Code
+
+#include "render/opengl/generated/render_opengl.meta.h"
+
+////////////////////////////////
+//~ rjf: Defines
+
+typedef char GLchar;
+typedef ptrdiff_t GLsizeiptr;
+typedef ptrdiff_t GLintptr;
+
+#define GL_FRAMEBUFFER_SRGB               0x8DB9
+#define GL_TEXTURE_MAX_LEVEL              0x813D
+
+#define GL_R8                             0x8229
+
+#define GL_ARRAY_BUFFER                   0x8892
+#define GL_STREAM_DRAW                    0x88E0
+#define GL_STREAM_READ                    0x88E1
+#define GL_STREAM_COPY                    0x88E2
+#define GL_STATIC_DRAW                    0x88E4
+#define GL_STATIC_READ                    0x88E5
+#define GL_STATIC_COPY                    0x88E6
+#define GL_DYNAMIC_DRAW                   0x88E8
+#define GL_DYNAMIC_READ                   0x88E9
+#define GL_DYNAMIC_COPY                   0x88EA
+
+#define GL_FRAGMENT_SHADER                0x8B30
+#define GL_VERTEX_SHADER                  0x8B31
+#define GL_TESS_EVALUATION_SHADER         0x8E87
+#define GL_TESS_CONTROL_SHADER            0x8E88
+#define GL_INFO_LOG_LENGTH                0x8B84
+
+#define GL_TEXTURE_2D_ARRAY               0x8C1A
+
+#define GL_COMPILE_STATUS                 0x8B81
+
+#define GL_TEXTURE0                       0x84C0
+#define GL_TEXTURE1                       0x84C1
+#define GL_TEXTURE2                       0x84C2
+#define GL_TEXTURE3                       0x84C3
+#define GL_TEXTURE4                       0x84C4
+#define GL_TEXTURE5                       0x84C5
+#define GL_TEXTURE6                       0x84C6
+#define GL_TEXTURE7                       0x84C7
+#define GL_TEXTURE8                       0x84C8
+#define GL_TEXTURE9                       0x84C9
+#define GL_TEXTURE10                      0x84CA
+#define GL_TEXTURE11                      0x84CB
+#define GL_TEXTURE12                      0x84CC
+#define GL_TEXTURE13                      0x84CD
+#define GL_TEXTURE14                      0x84CE
+#define GL_TEXTURE15                      0x84CF
+#define GL_TEXTURE16                      0x84D0
+#define GL_TEXTURE17                      0x84D1
+#define GL_TEXTURE18                      0x84D2
+#define GL_TEXTURE19                      0x84D3
+#define GL_TEXTURE20                      0x84D4
+#define GL_TEXTURE21                      0x84D5
+#define GL_TEXTURE22                      0x84D6
+#define GL_TEXTURE23                      0x84D7
+#define GL_TEXTURE24                      0x84D8
+#define GL_TEXTURE25                      0x84D9
+#define GL_TEXTURE26                      0x84DA
+#define GL_TEXTURE27                      0x84DB
+#define GL_TEXTURE28                      0x84DC
+#define GL_TEXTURE29                      0x84DD
+#define GL_TEXTURE30                      0x84DE
+#define GL_TEXTURE31                      0x84DF
+
+#define GL_DEBUG_OUTPUT                   0x92E0
+
+////////////////////////////////
+//~ rjf: OpenGL Procedure List
+
+#define R_OGL_ProcedureXList \
+X(glGenBuffers, void, (GLsizei n, GLuint *buffers))\
+X(glBindBuffer, void, (GLenum target, GLuint buffer))\
+X(glGenVertexArrays, void, (GLsizei n, GLuint *arrays))\
+X(glBindVertexArray, void, (GLuint array))\
+X(glCreateProgram, GLuint, (void))\
+X(glCreateShader, GLuint, (GLenum type))\
+X(glShaderSource, void, (GLuint shader, GLsizei count, char **string, GLint *length))\
+X(glCompileShader, void, (GLuint shader))\
+X(glGetShaderiv, void, (GLuint shader, GLenum pname, GLint *params))\
+X(glGetShaderInfoLog, void, (GLuint shader, GLsizei bufSize, GLsizei *length, char *infoLog))\
+X(glGetProgramiv, void, (GLuint program, GLenum pname, GLint *params))\
+X(glGetProgramInfoLog, void, (GLuint program, GLsizei bufSize, GLsizei *length, char *infoLog))\
+X(glAttachShader, void, (GLuint program, GLuint shader))\
+X(glLinkProgram, void, (GLuint program))\
+X(glValidateProgram, void, (GLuint program))\
+X(glDeleteShader, void, (GLuint shader))\
+X(glUseProgram, void, (GLuint program))\
+X(glGetUniformLocation, GLint, (GLuint program, char *name))\
+X(glGetAttribLocation, GLint, (GLuint program, char *name))\
+X(glEnableVertexAttribArray, void, (GLuint index))\
+X(glVertexAttribPointer, void, (GLuint index, GLint size, GLenum type, GLboolean normalized, GLsizei stride, const void *pointer))\
+X(glBufferData, void, (GLenum target, ptrdiff_t size, void *data, GLenum usage))\
+X(glBufferSubData, void, (GLenum target, ptrdiff_t offset, ptrdiff_t size, const void *data))\
+X(glBlendFuncSeparate, void, (GLenum sfactorRGB, GLenum dfactorRGB, GLenum sfactorAlpha, GLenum dfactorAlpha))\
+X(glUniform1f, void, (GLint location, GLfloat v0))\
+X(glUniform2f, void, (GLint location, GLfloat v0, GLfloat v1))\
+X(glUniform3f, void, (GLint location, GLfloat v0, GLfloat v1, GLfloat v2))\
+X(glUniform4f, void, (GLint location, GLfloat v0, GLfloat v1, GLfloat v2, GLfloat v3))\
+X(glUniformMatrix4fv, void, (GLint location, GLsizei count, GLboolean transpose, const GLfloat *value))\
+X(glUniform1i, void, (GLint location, GLint v0))\
+X(glTexImage3D, void, (GLenum target, GLint level, GLint internalformat, GLsizei width, GLsizei height, GLsizei depth, GLint border, GLenum format, GLenum type, const void *pixels))\
+X(glTexSubImage3D, void, (GLenum target, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLsizei width, GLsizei height, GLsizei depth, GLenum format, GLenum type, const void *pixels))\
+X(glGenerateMipmap, void, (GLenum target))\
+X(glBindAttribLocation, void, (GLuint programObj, GLuint index, char *name))\
+X(glBindFragDataLocation, void, (GLuint program, GLuint color, char *name))\
+X(glActiveTexture, void, (GLenum texture))\
+X(glVertexAttribDivisor, void, (GLuint index, GLuint divisor))\
+X(glDrawArraysInstanced, void, (GLenum mode, GLint first, GLsizei count, GLsizei instancecount))\
+X(glDebugMessageCallback, void, (void (*)(GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, const GLchar *message, const void *userParam), void *user_data))\
+
+#define X(name, r, p) typedef r name##_FunctionType p;
+R_OGL_ProcedureXList
+#undef X
+#define X(name, r, p) global name##_FunctionType *name = 0;
+R_OGL_ProcedureXList
+#undef X
+
+////////////////////////////////
+//~ rjf: State Types
+
+typedef struct R_OGL_FormatInfo R_OGL_FormatInfo;
+struct R_OGL_FormatInfo
+{
+  GLint internal_format;
+  GLenum format;
+  GLenum base_type;
+};
+
+typedef struct R_OGL_Tex2D R_OGL_Tex2D;
+struct R_OGL_Tex2D
+{
+  R_OGL_Tex2D *next;
+  GLuint id;
+  R_ResourceKind resource_kind;
+  R_Tex2DFormat fmt;
+  Vec2S32 size;
+};
+
+typedef struct R_OGL_State R_OGL_State;
+struct R_OGL_State
+{
+  Arena *arena;
+  R_OGL_Tex2D *free_tex2d;
+  GLuint shaders[R_OGL_ShaderKind_COUNT];
+  GLuint all_purpose_vao;
+  GLuint scratch_buffer_2mb;
+  GLuint white_texture;
+};
+
+////////////////////////////////
+//~ rjf: Globals
+
+global R_OGL_State *r_ogl_state = 0;
+
+////////////////////////////////
+//~ rjf: Helpers
+
+internal R_Handle r_ogl_handle_from_tex2d(R_OGL_Tex2D *t);
+internal R_OGL_Tex2D *r_ogl_tex2d_from_handle(R_Handle h);
+internal R_OGL_FormatInfo r_ogl_format_info_from_tex2dformat(R_Tex2DFormat fmt);
+internal void r_ogl_debug_message_callback(GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, const GLchar *message, const void *userParam);
+
+#define glUseProgramScope(...) DeferLoop(glUseProgram(__VA_ARGS__), glUseProgram(0))
+#define glBindVertexArrayScope(...) DeferLoop(glBindVertexArray(__VA_ARGS__), glBindVertexArray(0))
+
+////////////////////////////////
+//~ rjf: OS-Specific Hooks
+
+internal VoidProc *r_ogl_os_load_procedure(char *name);
+internal void r_ogl_os_init(CmdLine *cmdln);
+internal R_Handle r_ogl_os_window_equip(OS_Handle window);
+internal void r_ogl_os_window_unequip(OS_Handle os, R_Handle r);
+internal void r_ogl_os_select_window(OS_Handle os, R_Handle r);
+internal void r_ogl_os_window_swap(OS_Handle os, R_Handle r);
+
+#endif // RENDER_OPENGL_H
diff --git a/src/render/opengl/render_opengl.mdesk b/src/render/opengl/render_opengl.mdesk
new file mode 100644
index 00000000..d96874cd
--- /dev/null
+++ b/src/render/opengl/render_opengl.mdesk
@@ -0,0 +1,292 @@
+// Copyright (c) 2024 Epic Games Tools
+// Licensed under the MIT license (https://opensource.org/license/mit/)
+
+////////////////////////////////
+//~ rjf: Shader Table
+
+@table(name   name_lower    input_atts                          output_atts)
+R_OGL_ShaderTable:
+{
+  {Rect        rect          r_ogl_rect_input_attributes         r_ogl_single_color_output_attributes}
+  {Blur        blur          0                                   r_ogl_single_color_output_attributes}
+}
+
+@enum R_OGL_ShaderKind:
+{
+  @expand(R_OGL_ShaderTable a) `$(a.name)`,
+  COUNT
+}
+
+@data(String8) r_ogl_shader_kind_name_table:
+{
+  @expand(R_OGL_ShaderTable a) `str8_lit_comp("$(a.name_lower)")`,
+}
+
+@data(`String8 *`) r_ogl_shader_kind_vshad_src_table:
+{
+  @expand(R_OGL_ShaderTable a) `&r_ogl_$(a.name_lower)_vshad_src`,
+}
+
+@data(`String8 *`) r_ogl_shader_kind_pshad_src_table:
+{
+  @expand(R_OGL_ShaderTable a) `&r_ogl_$(a.name_lower)_pshad_src`,
+}
+
+@data(R_OGL_AttributeArray) r_ogl_shader_kind_input_attributes_table:
+{
+  @expand(R_OGL_ShaderTable a) `{ $(a.input_atts), $(a.input_atts != 0 -> "ArrayCount(" .. a.input_atts .. ")") }`,
+}
+
+@data(R_OGL_AttributeArray) r_ogl_shader_kind_output_attributes_table:
+{
+  @expand(R_OGL_ShaderTable a) `{ $(a.output_atts), ArrayCount($(a.output_atts)) }`,
+}
+
+////////////////////////////////
+//~ rjf: UI Rectangle Shaders
+
+//- rjf: vertex
+@embed_string r_ogl_rect_vshad_src:
+```
+#version 330 core
+
+in vec4 c2v_dst_rect;
+in vec4 c2v_src_rect;
+in vec4 c2v_colors_0;
+in vec4 c2v_colors_1;
+in vec4 c2v_colors_2;
+in vec4 c2v_colors_3;
+in vec4 c2v_corner_radii;
+in vec4 c2v_style;  // x: border_thickness_px, y: softness_px, z: omit_texture, w: unused
+
+out vec2 v2p_sdf_sample_pos;
+out vec2 v2p_texcoord_pct;
+out vec2 v2p_rect_half_size_px;
+out vec4 v2p_tint;
+out float v2p_corner_radius;
+out float v2p_border_thickness;
+out float v2p_softness;
+out float v2p_omit_texture;
+
+uniform sampler2D u_tex_color;
+uniform vec2 u_viewport_size_px;
+
+void main(void)
+{
+  // rjf: constants
+  vec2 vertices[] = vec2[](vec2(-1, -1), vec2(-1, +1), vec2(+1, -1), vec2(+1, +1));
+  
+  // rjf: find dst position
+  vec2 dst_half_size = (c2v_dst_rect.zw - c2v_dst_rect.xy) / 2;
+  vec2 dst_center    = (c2v_dst_rect.zw + c2v_dst_rect.xy) / 2;
+  vec2 dst_position  = vertices[gl_VertexID] * dst_half_size + dst_center;
+  
+  // rjf: find src position
+  vec2 src_half_size = (c2v_src_rect.zw - c2v_src_rect.xy) / 2;
+  vec2 src_center    = (c2v_src_rect.zw + c2v_src_rect.xy) / 2;
+  vec2 src_position  = vertices[gl_VertexID] * src_half_size + src_center;
+  
+  // rjf: find color
+  vec4 colors[] = vec4[](c2v_colors_0, c2v_colors_1, c2v_colors_2, c2v_colors_3);
+  vec4 color = colors[gl_VertexID];
+  
+  // rjf: find corner radius
+  float corner_radii[] = float[](c2v_corner_radii.x, c2v_corner_radii.y, c2v_corner_radii.z, c2v_corner_radii.w);
+  float corner_radius = corner_radii[gl_VertexID];
+  
+  // rjf: fill outputs
+  vec2 dst_verts_pct = vec2(((gl_VertexID >> 1) != 1) ? 1.f : 0.f,
+                            ((gl_VertexID & 1) != 0)  ? 0.f : 1.f);
+  ivec2 u_tex_color_size_i = textureSize(u_tex_color, 0);
+  vec2 u_tex_color_size = vec2(float(u_tex_color_size_i.x), float(u_tex_color_size_i.y));
+  {
+    gl_Position = vec4(2 * dst_position.x / u_viewport_size_px.x - 1,
+                       2 * (1 - dst_position.y / u_viewport_size_px.y) - 1,
+                       0.0, 1.0);
+    v2p_sdf_sample_pos    = (2.f * dst_verts_pct - 1.f) * dst_half_size;
+    v2p_texcoord_pct      = src_position / u_tex_color_size;
+    v2p_rect_half_size_px = dst_half_size;
+    v2p_tint              = color;
+    v2p_corner_radius     = corner_radius;
+    v2p_border_thickness  = c2v_style.x;
+    v2p_softness          = c2v_style.y;
+    v2p_omit_texture      = c2v_style.z;
+  }
+}
+```
+
+//- rjf: pixel
+@embed_string r_ogl_rect_pshad_src:
+```
+#version 330 core
+
+in vec2 v2p_sdf_sample_pos;
+in vec2 v2p_texcoord_pct;
+in vec2 v2p_rect_half_size_px;
+in vec4 v2p_tint;
+in float v2p_corner_radius;
+in float v2p_border_thickness;
+in float v2p_softness;
+in float v2p_omit_texture;
+
+out vec4 final_color;
+
+uniform float u_opacity;
+uniform sampler2D u_tex_color;
+uniform mat4 u_texture_sample_channel_map;
+
+float rect_sdf(vec2 sample_pos, vec2 rect_half_size, float r)
+{
+  return length(max(abs(sample_pos) - rect_half_size + r, 0.0)) - r;
+}
+
+float linear_from_srgb_f32(float x)
+{
+  return x < 0.0404482362771082 ? x / 12.92 : pow((x + 0.055) / 1.055, 2.4);
+}
+
+vec4 linear_from_srgba(vec4 v)
+{
+  vec4 result = vec4(linear_from_srgb_f32(v.x),
+                     linear_from_srgb_f32(v.y),
+                     linear_from_srgb_f32(v.z),
+                     v.w);
+  return result;
+}
+
+void main(void)
+{
+  // rjf: sample texture
+  vec4 albedo_sample = vec4(1, 1, 1, 1);
+  if(v2p_omit_texture < 1)
+  {
+    albedo_sample = u_texture_sample_channel_map * texture(u_tex_color, v2p_texcoord_pct);
+    albedo_sample = linear_from_srgba(albedo_sample);
+  }
+  
+  // rjf: sample for borders
+  float border_sdf_t = 1;
+  if(v2p_border_thickness > 0)
+  {
+    float border_sdf_s = rect_sdf(v2p_sdf_sample_pos,
+                                  v2p_rect_half_size_px - vec2(v2p_softness*2.f, v2p_softness*2.f) - v2p_border_thickness,
+                                  max(v2p_corner_radius-v2p_border_thickness, 0));
+    border_sdf_t = smoothstep(0, 2*v2p_softness, border_sdf_s);
+  }
+  if(border_sdf_t < 0.001f)
+  {
+    discard;
+  }
+  
+  // rjf: sample for corners
+  float corner_sdf_t = 1;
+  if(v2p_corner_radius > 0 || v2p_softness > 0.75f)
+  {
+    float corner_sdf_s = rect_sdf(v2p_sdf_sample_pos,
+                                  v2p_rect_half_size_px - vec2(v2p_softness*2.f, v2p_softness*2.f),
+                                  v2p_corner_radius);
+    corner_sdf_t = 1-smoothstep(0, 2*v2p_softness, corner_sdf_s);
+  }
+  
+  // rjf: form+return final color
+  final_color = albedo_sample;
+  final_color *= v2p_tint;
+  final_color.a *= u_opacity;
+  final_color.a *= corner_sdf_t;
+  final_color.a *= border_sdf_t;
+}
+```
+
+////////////////////////////////
+//~ rjf: Blur Shaders
+
+//- rjf: vertex
+@embed_string r_ogl_blur_vshad_src:
+```
+#version 330 core
+
+uniform vec4 rect;
+uniform vec4 corner_radii_px;
+uniform vec2 viewport_size;
+uniform uint blur_count;
+
+out vec2 texcoord;
+out vec2 sdf_sample_pos;
+out vec2 rect_half_size;
+out float corner_radius;
+
+void main(void)
+{
+  vec2 vertex_positions_scrn[] = vec2[](rect.xw,
+                                        rect.xy,
+                                        rect.zw,
+                                        rect.zy);
+  float corner_radii_px[] = float[](corner_radii_px.y,
+                                    corner_radii_px.x,
+                                    corner_radii_px.w,
+                                    corner_radii_px.z);
+  vec2 cornercoords_pct = vec2((gl_VertexID >> 1) != 0 ? 1.f : 0.f,
+                               (gl_VertexID & 1) != 0  ? 0.f : 1.f);
+  
+  vec2 vertex_position_pct = vertex_positions_scrn[gl_VertexID] / viewport_size;
+  vec2 vertex_position_scr = 2.f * vertex_position_pct - 1.f;
+  
+  vec2 rect_half_size = vec2((rect.z-rect.x)/2, (rect.w-rect.y)/2);
+  
+  gl_Position = vec4(vertex_position_scr.x, -vertex_position_scr.y, 0.f, 1.f);
+  texcoord = vertex_position_pct;
+  sdf_sample_pos = (2.f * cornercoords_pct - 1.f) * rect_half_size;
+  rect_half_size = rect_half_size - 2.f;
+  corner_radius = corner_radii_px[gl_VertexID];
+}
+```
+
+//- rjf: pixel
+@embed_string r_ogl_blur_pshad_src:
+```
+#version 330 core
+
+uniform sampler2D tex;
+uniform vec4 kernel[32];
+uniform int blur_count;
+uniform vec2 direction;
+
+in vec2 texcoord;
+in vec2 sdf_sample_pos;
+in vec2 rect_half_size;
+in float corner_radius;
+
+out vec4 final_color;
+
+float rect_sdf(vec2 sample_pos, vec2 rect_half_size, float r)
+{
+  return length(max(abs(sample_pos) - rect_half_size + r, 0.0)) - r;
+}
+
+void main(void)
+{
+  // rjf: blend weighted texture samples into color
+  vec3 color = kernel[0].x * texture(tex, texcoord).rgb;
+  
+  for(int i = 1; i < blur_count; i += 1)
+  {
+    float weight = kernel[i].x;
+    float offset = kernel[i].y;
+    color += weight * texture(tex, texcoord - offset * direction).rgb;
+    color += weight * texture(tex, texcoord + offset * direction).rgb;
+  }
+  
+  // rjf: sample for corners
+  float corner_sdf_s = rect_sdf(sdf_sample_pos, rect_half_size, corner_radius);
+  float corner_sdf_t = 1-smoothstep(0, 2, corner_sdf_s);
+  
+  // rjf: weight output color by sdf
+  // this is doing alpha testing, leave blurring only where mostly opaque pixels are
+  if(corner_sdf_t < 0.9f)
+  {
+    discard;
+  }
+  
+  final_color = vec4(color, 1.f);
+}
+```
diff --git a/src/render/opengl/win32/render_opengl_win32.c b/src/render/opengl/win32/render_opengl_win32.c
new file mode 100644
index 00000000..7b40d711
--- /dev/null
+++ b/src/render/opengl/win32/render_opengl_win32.c
@@ -0,0 +1,184 @@
+// Copyright (c) 2024 Epic Games Tools
+// Licensed under the MIT license (https://opensource.org/license/mit/)
+
+internal VoidProc *
+r_ogl_os_load_procedure(char *name)
+{
+  VoidProc *p = (VoidProc*)wglGetProcAddress(name);
+  if(p == (VoidProc*)1 || p == (VoidProc*)2 || p == (VoidProc*)3 || p == (VoidProc*)-1)
+  {
+    p = 0;
+  }
+  return p;
+}
+
+internal void
+r_ogl_os_init(CmdLine *cmdline)
+{
+  //- rjf: create bootstrapping window
+  HWND bootstrap_hwnd = 0;
+  {
+    WNDCLASSEXW wndclass = { sizeof(wndclass) };
+    wndclass.lpfnWndProc = DefWindowProcW;
+    wndclass.hInstance = GetModuleHandle(0);
+    wndclass.lpszClassName = L"bootstrap-window";
+    ATOM wndatom = RegisterClassExW(&wndclass);
+    bootstrap_hwnd = CreateWindowExW(0, L"bootstrap-window", L"", 0,
+                                     CW_USEDEFAULT, CW_USEDEFAULT,
+                                     CW_USEDEFAULT, CW_USEDEFAULT,
+                                     0, 0, wndclass.hInstance, 0);
+  }
+  
+  //- rjf: grab dc
+  HDC dc = GetDC(bootstrap_hwnd);
+  
+  //- rjf: build pixel format descriptor
+  int pf = 0;
+  {
+    PIXELFORMATDESCRIPTOR pfd = {sizeof(pfd)};
+    pfd.nVersion = 1;
+    pfd.dwFlags = PFD_DRAW_TO_WINDOW|PFD_SUPPORT_OPENGL|PFD_DOUBLEBUFFER;
+    pfd.iPixelType = PFD_TYPE_RGBA;
+    pfd.cColorBits = 32;
+    pfd.cDepthBits = 24;
+    pfd.cStencilBits = 8;
+    pfd.iLayerType = PFD_MAIN_PLANE;
+    pf = ChoosePixelFormat(dc, &pfd);
+    BOOL describe = DescribePixelFormat(dc, pf, sizeof(pfd), &pfd);
+    BOOL set_pf = SetPixelFormat(dc, pf, &pfd);
+  }
+  
+  //- rjf: make bootstrap ctx + make current
+  HGLRC bootstrap_ctx = wglCreateContext(dc);
+  wglMakeCurrent(dc, bootstrap_ctx);
+  
+  //- rjf: load modern extensions
+  wglChoosePixelFormatARB    = (FNWGLCHOOSEPIXELFORMATARBPROC*)   r_ogl_os_load_procedure("wglChoosePixelFormatARB");
+  wglCreateContextAttribsARB = (FNWGLCREATECONTEXTATTRIBSARBPROC*)r_ogl_os_load_procedure("wglCreateContextAttribsARB");
+  wglSwapIntervalEXT         = (FNWGLSWAPINTERVALEXTPROC*)        r_ogl_os_load_procedure("wglSwapIntervalEXT");
+  
+  //- rjf: set up real pixel format
+  {
+    int pf_attribs_i[] =
+    {
+      WGL_DRAW_TO_WINDOW_ARB, 1,
+      WGL_SUPPORT_OPENGL_ARB, 1,
+      WGL_DOUBLE_BUFFER_ARB, 1,
+      WGL_PIXEL_TYPE_ARB, WGL_TYPE_RGBA_ARB,
+      WGL_COLOR_BITS_ARB, 32,
+      WGL_DEPTH_BITS_ARB, 24,
+      WGL_STENCIL_BITS_ARB, 8,
+      0
+    };
+    UINT num_formats = 0;
+    wglChoosePixelFormatARB(dc, pf_attribs_i, 0, 1, &pf, &num_formats);
+  }
+  
+  //- rjf: make real gl ctx
+  HGLRC real_ctx = 0;
+  if(pf)
+  {
+    const int context_attribs[] =
+    {
+      WGL_CONTEXT_MAJOR_VERSION_ARB, 3,
+      WGL_CONTEXT_MINOR_VERSION_ARB, 3,
+      WGL_CONTEXT_FLAGS_ARB, WGL_CONTEXT_DEBUG_BIT_ARB,
+      0
+    };
+    real_ctx = wglCreateContextAttribsARB(dc, bootstrap_ctx, context_attribs);
+    r_ogl_w32_hglrc = real_ctx;
+  }
+  
+  //- rjf: clean up bootstrap context
+  wglMakeCurrent(dc, 0);
+  wglDeleteContext(bootstrap_ctx);
+  wglMakeCurrent(dc, real_ctx);
+  wglSwapIntervalEXT(1);
+  ReleaseDC(bootstrap_hwnd, dc);
+  DestroyWindow(bootstrap_hwnd);
+}
+
+internal R_Handle
+r_ogl_os_window_equip(OS_Handle window)
+{
+  //- rjf: unpack window
+  OS_W32_Window *w = os_w32_window_from_handle(window);
+  HWND hwnd = w->hwnd;
+  HDC hdc = GetDC(hwnd);
+  
+  //- rjf: select in ctx
+  wglMakeCurrent(hdc, r_ogl_w32_hglrc);
+  
+  //- rjf: setup real pixel format
+  int pixel_format = 0;
+  UINT num_formats = 0;
+  int pf_attribs_i[] =
+  {
+    WGL_DRAW_TO_WINDOW_ARB, GL_TRUE,
+    WGL_SUPPORT_OPENGL_ARB, GL_TRUE,
+    WGL_DOUBLE_BUFFER_ARB, GL_TRUE,
+    WGL_PIXEL_TYPE_ARB, WGL_TYPE_RGBA_ARB,
+    WGL_COLOR_BITS_ARB, 32,
+    WGL_DEPTH_BITS_ARB, 24,
+    WGL_STENCIL_BITS_ARB, 8,
+    0
+  };
+  wglChoosePixelFormatARB(hdc,
+                          pf_attribs_i,
+                          0,
+                          1,
+                          &pixel_format,
+                          &num_formats);
+  
+  // NOTE(rjf): This doesn't seem to be necessary for SetPixelFormat, we can
+  // just pass 0 for it, and SetPixelFormat needs to be called here, but the
+  // docs don't seem to suggest that 0 is an acceptable value, so I am just
+  // filling this out with the same attribs as that for the wgl function,
+  // and passing it.
+  PIXELFORMATDESCRIPTOR pfd = {sizeof(pfd)};
+  pfd.nVersion = 1;
+  pfd.dwFlags = PFD_DRAW_TO_WINDOW|PFD_SUPPORT_OPENGL|PFD_DOUBLEBUFFER;
+  pfd.iPixelType = PFD_TYPE_RGBA;
+  pfd.cColorBits = 32;
+  pfd.cDepthBits = 24;
+  pfd.cStencilBits = 8;
+  pfd.iLayerType = PFD_MAIN_PLANE;
+  
+  //- rjf: set pixel format
+  SetPixelFormat(hdc, pixel_format, &pfd);
+  
+  //- rjf: release hdc
+  ReleaseDC(hwnd, hdc);
+  R_Handle result = {0};
+  return result;
+}
+
+internal void
+r_ogl_os_window_unequip(OS_Handle os, R_Handle r)
+{
+}
+
+internal void
+r_ogl_os_select_window(OS_Handle os, R_Handle r)
+{
+  OS_W32_Window *w = os_w32_window_from_handle(os);
+  if(w != 0)
+  {
+    HWND hwnd = w->hwnd;
+    HDC hdc = GetDC(hwnd);
+    wglMakeCurrent(hdc, r_ogl_w32_hglrc);
+    ReleaseDC(hwnd, hdc);
+  }
+}
+
+internal void
+r_ogl_os_window_swap(OS_Handle os, R_Handle r)
+{
+  OS_W32_Window *w = os_w32_window_from_handle(os);
+  if(w != 0)
+  {
+    HDC dc = GetDC(w->hwnd);
+    SwapBuffers(dc);
+    ReleaseDC(w->hwnd, dc);
+  }
+}
diff --git a/src/render/opengl/win32/render_opengl_win32.h b/src/render/opengl/win32/render_opengl_win32.h
new file mode 100644
index 00000000..24e53c14
--- /dev/null
+++ b/src/render/opengl/win32/render_opengl_win32.h
@@ -0,0 +1,34 @@
+// Copyright (c) 2024 Epic Games Tools
+// Licensed under the MIT license (https://opensource.org/license/mit/)
+
+#ifndef RENDER_OPENGL_WIN32_H
+#define RENDER_OPENGL_WIN32_H
+
+#include <GL/gl.h>
+#pragma comment(lib, "opengl32")
+
+#define WGL_DRAW_TO_WINDOW_ARB            0x2001
+#define WGL_SUPPORT_OPENGL_ARB            0x2010
+#define WGL_DOUBLE_BUFFER_ARB             0x2011
+#define WGL_PIXEL_TYPE_ARB                0x2013
+#define WGL_COLOR_BITS_ARB                0x2014
+#define WGL_DEPTH_BITS_ARB                0x2022
+#define WGL_STENCIL_BITS_ARB              0x2023
+#define WGL_TYPE_RGBA_ARB                 0x202B
+#define WGL_CONTEXT_DEBUG_BIT_ARB         0x00000001
+
+#define WGL_CONTEXT_MAJOR_VERSION_ARB     0x2091
+#define WGL_CONTEXT_MINOR_VERSION_ARB     0x2092
+#define WGL_CONTEXT_FLAGS_ARB             0x2094
+
+typedef BOOL WINAPI FNWGLCHOOSEPIXELFORMATARBPROC(HDC hdc, const int *piAttribIList, const FLOAT *pfAttribFList, UINT nMaxFormats, int *piFormats, UINT *nNumFormats);
+typedef HGLRC WINAPI FNWGLCREATECONTEXTATTRIBSARBPROC(HDC hDC, HGLRC hShareContext, const int *attribList);
+typedef BOOL WINAPI FNWGLSWAPINTERVALEXTPROC(int interval);
+
+FNWGLCHOOSEPIXELFORMATARBPROC *wglChoosePixelFormatARB;
+FNWGLCREATECONTEXTATTRIBSARBPROC *wglCreateContextAttribsARB;
+FNWGLSWAPINTERVALEXTPROC *wglSwapIntervalEXT;
+
+global HGLRC r_ogl_w32_hglrc = 0;
+
+#endif // RENDER_OPENGL_WIN32_H
diff --git a/src/render/render_core.c b/src/render/render_core.c
index 4d6ebdf7..80ca84bf 100644
--- a/src/render/render_core.c
+++ b/src/render/render_core.c
@@ -6,6 +6,33 @@
 
 #include "generated/render.meta.c"
 
+////////////////////////////////
+//~ rjf: Helpers
+
+internal Mat4x4F32
+r_sample_channel_map_from_tex2dformat(R_Tex2DFormat fmt)
+{
+  Mat4x4F32 result =
+  {
+    {
+      {1, 0, 0, 0},
+      {0, 1, 0, 0},
+      {0, 0, 1, 0},
+      {0, 0, 0, 1},
+    }
+  };
+  switch(fmt)
+  {
+    default:{}break;
+    case R_Tex2DFormat_R8:
+    {
+      MemoryZeroArray(result.v[0]);
+      result.v[0][0] = result.v[0][1] = result.v[0][2] = result.v[0][3] = 1.f;
+    }break;
+  }
+  return result;
+}
+
 ////////////////////////////////
 //~ rjf: Basic Type Functions
 
diff --git a/src/render/render_core.h b/src/render/render_core.h
index a7ef99c9..7725c5a3 100644
--- a/src/render/render_core.h
+++ b/src/render/render_core.h
@@ -194,6 +194,11 @@ struct R_PassList
   U64 count;
 };
 
+////////////////////////////////
+//~ rjf: Helpers
+
+internal Mat4x4F32 r_sample_channel_map_from_tex2dformat(R_Tex2DFormat fmt);
+
 ////////////////////////////////
 //~ rjf: Handle Type Functions
 
diff --git a/src/render/render_inc.c b/src/render/render_inc.c
index 52e5c365..bb15be84 100644
--- a/src/render/render_inc.c
+++ b/src/render/render_inc.c
@@ -10,6 +10,8 @@
 # include "stub/render_stub.c"
 #elif R_BACKEND == R_BACKEND_D3D11
 # include "d3d11/render_d3d11.c"
+#elif R_BACKEND == R_BACKEND_OPENGL
+# include "opengl/render_opengl.c"
 #else
 # error Renderer backend not specified.
 #endif
diff --git a/src/render/render_inc.h b/src/render/render_inc.h
index 64802e5c..d0e87c3c 100644
--- a/src/render/render_inc.h
+++ b/src/render/render_inc.h
@@ -9,12 +9,15 @@
 
 #define R_BACKEND_STUB 0
 #define R_BACKEND_D3D11 1
+#define R_BACKEND_OPENGL 2
 
 ////////////////////////////////
 //~ rjf: Decide On Backend
 
 #if !defined(R_BACKEND) && OS_WINDOWS
 # define R_BACKEND R_BACKEND_D3D11
+#elif !defined(R_BACKEND) && OS_LINUX
+# define R_BACKEND R_BACKEND_OPENGL
 #endif
 
 ////////////////////////////////
@@ -29,6 +32,8 @@
 # include "stub/render_stub.h"
 #elif R_BACKEND == R_BACKEND_D3D11
 # include "d3d11/render_d3d11.h"
+#elif R_BACKEND == R_BACKEND_OPENGL
+# include "opengl/render_opengl.h"
 #else
 # error Renderer backend not specified.
 #endif