added shadowmap renderer

assets/shaders/shadowmap.vert

@@ -0,0 +1,55 @@
+#version 450
+#extension GL_EXT_nonuniform_qualifier : require
+
+struct Vertex {
+  vec4 position;
+  vec4 normal;
+  vec2 uv[2];
+  vec4 tangent;
+  vec4 bitangent; // No longer needed. // TODO remove
+};
+
+struct Light {
+  mat4 tranform;
+  vec4 color;
+  float intensity;
+};
+
+layout( push_constant ) uniform constants
+{
+	mat4 transform;
+  uint indexBufferIndex;
+  uint vertexBufferIndex;
+} PushConstants;
+
+layout(set = 0, binding = 1) buffer VertexBuffer {
+  layout(align = 16) Vertex vertices[];
+} VertexBuffers[];
+
+layout(set = 0, binding = 2) buffer IndexBuffer {
+  uint indices[];
+} IndexBuffers[];
+
+const int MAX_LIGHT_COUNT = 128;
+
+layout(set = 1, binding = 0) uniform LightBuffer {
+  layout(align = 16) Light lights[MAX_LIGHT_COUNT];
+} LightsBuffer;
+
+float near = 10;
+float far = 0.1;
+
+void main()
+{
+  uint index = IndexBuffers[ PushConstants.indexBufferIndex ].indices[gl_VertexIndex];
+  Vertex vertex = VertexBuffers[ PushConstants.vertexBufferIndex ].vertices[ index ];
+
+  mat4 lightView = transpose(inverse( LightsBuffer.lights[0].tranform));
+  mat4 lightProjection = mat4(1.0);
+  lightProjection[3][2] = -(far+near)/(far-near);
+  lightProjection[2][2] = -2/(far-near);
+
+  mat4 lightSpaceMatrix = lightProjection * lightView;
+
+  gl_Position = lightSpaceMatrix * PushConstants.transform * vec4(vertex.position.xyz, 1.0);
+}