feat(shaders): Implement dynamic background shader

src/shader_manager.py

@@ -1,9 +1,9 @@
-# src/shader_manager.py
 import OpenGL.GL as gl
 
 class ShaderManager:
  def __init__(self):
   self.program = None
+  self.bg_program = None
 
  def compile_shader(self, vertex_src: str, fragment_src: str) -> int:
   program = gl.glCreateProgram()
@@ -33,7 +33,6 @@ class ShaderManager:
     info_log = info_log.decode()
    raise RuntimeError(f"Program linking failed: {info_log}")
   
-  # Optional: delete shaders as they are linked into the program
   gl.glDeleteShader(vert_shader)
   gl.glDeleteShader(frag_shader)
   
@@ -60,3 +59,42 @@ class ShaderManager:
      gl.glUniform3f(loc, value[0], value[1], value[2])
     elif len(value) == 4:
      gl.glUniform4f(loc, value[0], value[1], value[2], value[3])
+
+ def setup_background_shader(self):
+  vertex_src = """
+#version 330 core
+const vec2 positions[4] = vec2[](
+ vec2(-1.0, -1.0),
+ vec2( 1.0, -1.0),
+ vec2(-1.0,  1.0),
+ vec2( 1.0,  1.0)
+);
+void main() {
+ gl_Position = vec4(positions[gl_VertexID], 0.0, 1.0);
+}
+"""
+  fragment_src = """
+#version 330 core
+uniform float u_time;
+uniform vec2 u_resolution;
+out vec4 FragColor;
+void main() {
+ vec2 uv = gl_FragCoord.xy / u_resolution.xy;
+ vec3 col = 0.5 + 0.5 * cos(u_time + uv.xyx + vec3(0, 2, 4));
+ FragColor = vec4(col, 1.0);
+}
+"""
+  self.bg_program = self.compile_shader(vertex_src, fragment_src)
+
+ def render_background(self, width, height, time):
+  if not self.bg_program:
+   return
+  gl.glUseProgram(self.bg_program)
+  u_time_loc = gl.glGetUniformLocation(self.bg_program, "u_time")
+  if u_time_loc != -1:
+   gl.glUniform1f(u_time_loc, float(time))
+  u_res_loc = gl.glGetUniformLocation(self.bg_program, "u_resolution")
+  if u_res_loc != -1:
+   gl.glUniform2f(u_res_loc, float(width), float(height))
+  gl.glDrawArrays(gl.GL_TRIANGLE_STRIP, 0, 4)
+  gl.glUseProgram(0)