Shadows working but look dumb. The issue so far was that framebuffer.cpp interferes with the framebuffer used to create the shadow map.

33-shadow-mapping/shaders/33-shadow_dbg.frag.glsl

@@ -0,0 +1,22 @@
+#version 330 core
+out vec4 FragColor;
+
+in vec2 TexCoords;
+
+uniform sampler2D shadowMap;
+uniform float near_plane;
+uniform float far_plane;
+
+// required when using a perspective projection matrix
+float LinearizeDepth(float depth)
+{
+    float z = depth * 2.0 - 1.0; // Back to NDC
+    return (2.0 * near_plane * far_plane) / (far_plane + near_plane - z * (far_plane - near_plane));
+}
+
+void main()
+{
+    float depthValue = texture(shadowMap, TexCoords).r;
+    // FragColor = vec4(vec3(LinearizeDepth(depthValue) / far_plane), 1.0); // perspective
+    FragColor = vec4(vec3(depthValue), 1.0); // orthographic
+}