From f9018c987884055e62aca1184fe0d78843b3156d Mon Sep 17 00:00:00 2001
From: j3oss <youssef.assem.mohamed@gmail.com>
Date: Wed, 21 Jul 2021 18:49:26 +0200
Subject: [PATCH] added shadowmap renderer

---
 assets/shaders/shadowmap.vert | 55 +++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 assets/shaders/shadowmap.vert

diff --git a/assets/shaders/shadowmap.vert b/assets/shaders/shadowmap.vert
new file mode 100644
index 0000000..294f46c
--- /dev/null
+++ b/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);
+}