fix(shader): Add proper VAO setup for OpenGL 3.3 core profile

- Create _create_quad_vao() method that creates VAO with vertex buffer
- Use explicit vertex attributes (a_position, a_texcoord) in shaders
- Bind VAO before glDrawArrays calls
- Use ctypes for proper buffer sizing

src/gui_2.py

@@ -4055,10 +4055,6 @@ def hello():
   return True
 
  def _pre_new_frame(self) -> None:
-  # DISABLED: OpenGL 3.3 core profile doesn't support fixed-function glBegin/glEnd
-  # and vertex attrib setup is failing in imgui-bundle context
-  # TODO: Fix with proper VAO setup or use different OpenGL context
-  return
   if not self.ui_frosted_glass_enabled:
    return
   ws = imgui.get_io().display_size

src/shader_manager.py

@@ -162,6 +162,7 @@ class BlurPipeline:
   self.h_blur_program: int | None = None
   self.v_blur_program: int | None = None
   self.deepsea_program: int | None = None
+  self._quad_vao: int | None = None
   self._fb_width: int = 0
   self._fb_height: int = 0
   self._fb_scale: int = 1
@@ -209,6 +210,26 @@ class BlurPipeline:
   gl.glBindTexture(gl.GL_TEXTURE_2D, 0)
   return fbo, tex
 
+ def _create_quad_vao(self) -> int:
+  import ctypes
+  vao = gl.glGenVertexArrays(1)
+  gl.glBindVertexArray(vao)
+  vertices = (ctypes.c_float * 16)(
+   -1.0, -1.0, 0.0, 0.0,
+    1.0, -1.0, 1.0, 0.0,
+   -1.0,  1.0, 0.0, 1.0,
+    1.0,  1.0, 1.0, 1.0
+  )
+  vbo = gl.glGenBuffers(1)
+  gl.glBindBuffer(gl.GL_ARRAY_BUFFER, vbo)
+  gl.glBufferData(gl.GL_ARRAY_BUFFER, ctypes.sizeof(vertices), vertices, gl.GL_STATIC_DRAW)
+  gl.glEnableVertexAttribArray(0)
+  gl.glVertexAttribPointer(0, 2, gl.GL_FLOAT, gl.GL_FALSE, 16, None)
+  gl.glEnableVertexAttribArray(1)
+  gl.glVertexAttribPointer(1, 2, gl.GL_FLOAT, gl.GL_FALSE, 16, ctypes.c_void_p(8))
+  gl.glBindVertexArray(0)
+  return vao
+
  def setup_fbos(self, width: int, height: int, fb_scale: float = 1.0):
   scale = max(1, int(fb_scale))
   blur_w = max(1, (width * scale) // 4)
@@ -225,8 +246,8 @@ class BlurPipeline:
  def compile_blur_shaders(self):
   vert_src = """
 #version 330 core
-in vec2 a_position;
+layout(location = 0) in vec2 a_position;
-in vec2 a_texcoord;
+layout(location = 1) in vec2 a_texcoord;
 out vec2 v_uv;
 void main() {
  gl_Position = vec4(a_position, 0.0, 1.0);
@@ -289,8 +310,8 @@ void main() {
  def compile_deepsea_shader(self):
   vert_src = """
 #version 330 core
-in vec2 a_position;
+layout(location = 0) in vec2 a_position;
-in vec2 a_texcoord;
+layout(location = 1) in vec2 a_texcoord;
 out vec2 v_uv;
 void main() {
  gl_Position = vec4(a_position, 0.0, 1.0);
@@ -356,9 +377,10 @@ void main() {
 }
 """
   self.deepsea_program = self._compile_shader(vert_src, frag_src)
+  self._quad_vao = self._create_quad_vao()
 
  def render_deepsea_to_fbo(self, width: int, height: int, time: float):
-  if not self.deepsea_program or not self.scene_fbo:
+  if not self.deepsea_program or not self.scene_fbo or not self._quad_vao:
    return
   scene_w = width * self._fb_scale
   scene_h = height * self._fb_scale
@@ -367,19 +389,15 @@ void main() {
   gl.glClearColor(0.01, 0.05, 0.12, 1.0)
   gl.glClear(gl.GL_COLOR_BUFFER_BIT)
   gl.glUseProgram(self.deepsea_program)
-  u_time = gl.glGetUniformLocation(self.deepsea_program, "u_time")
+  u_time_loc = gl.glGetUniformLocation(self.deepsea_program, "u_time")
-  if u_time != -1:
+  if u_time_loc != -1:
-   gl.glUniform1f(u_time, time)
+   gl.glUniform1f(u_time_loc, time)
-  u_res = gl.glGetUniformLocation(self.deepsea_program, "u_resolution")
+  u_res_loc = gl.glGetUniformLocation(self.deepsea_program, "u_resolution")
-  if u_res != -1:
+  if u_res_loc != -1:
-   gl.glUniform2f(u_res, float(scene_w), float(scene_h))
+   gl.glUniform2f(u_res_loc, float(scene_w), float(scene_h))
-  # Draw fullscreen quad using deprecated but working glBegin/glEnd
+  gl.glBindVertexArray(self._quad_vao)
-  gl.glBegin(gl.GL_TRIANGLE_STRIP)
+  gl.glDrawArrays(gl.GL_TRIANGLE_STRIP, 0, 4)
-  gl.glVertex2f(-1.0, -1.0); gl.glTexCoord2f(0.0, 0.0)
+  gl.glBindVertexArray(0)
-  gl.glVertex2f( 1.0, -1.0); gl.glTexCoord2f(1.0, 0.0)
-  gl.glVertex2f(-1.0,  1.0); gl.glTexCoord2f(0.0, 1.0)
-  gl.glVertex2f( 1.0,  1.0); gl.glTexCoord2f(1.0, 1.0)
-  gl.glEnd()
   gl.glUseProgram(0)
   gl.glBindFramebuffer(gl.GL_FRAMEBUFFER, 0)
 
@@ -393,12 +411,9 @@ void main() {
   u_ts = gl.glGetUniformLocation(program, "u_texel_size")
   if u_ts != -1:
    gl.glUniform2f(u_ts, texel_size[0], texel_size[1])
-  gl.glBegin(gl.GL_TRIANGLE_STRIP)
+  gl.glBindVertexArray(self._quad_vao)
-  gl.glVertex2f(-1.0, -1.0); gl.glTexCoord2f(0.0, 0.0)
+  gl.glDrawArrays(gl.GL_TRIANGLE_STRIP, 0, 4)
-  gl.glVertex2f( 1.0, -1.0); gl.glTexCoord2f(1.0, 0.0)
+  gl.glBindVertexArray(0)
-  gl.glVertex2f(-1.0,  1.0); gl.glTexCoord2f(0.0, 1.0)
-  gl.glVertex2f( 1.0,  1.0); gl.glTexCoord2f(1.0, 1.0)
-  gl.glEnd()
   gl.glBindTexture(gl.GL_TEXTURE_2D, 0)
   gl.glUseProgram(0)
 
@@ -445,6 +460,8 @@ void main() {
   if progs:
    for p in progs:
     gl.glDeleteProgram(p)
+  if self._quad_vao:
+   gl.glDeleteVertexArrays(1, [self._quad_vao])
   self.scene_fbo = None
   self.scene_tex = None
   self.blur_fbo_a = None
@@ -454,3 +471,4 @@ void main() {
   self.h_blur_program = None
   self.v_blur_program = None
   self.deepsea_program = None
+  self._quad_vao = None