29 lines
709 B
GLSL
29 lines
709 B
GLSL
#version 450
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// 在没有顶点缓冲区的情况下，通过顶点ID生成全屏 quad
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// 顶点ID: 0=(-1,-1), 1=(1,-1), 2=(-1,1), 3=(1,1)
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out gl_PerVertex {
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vec4 gl_Position;
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};
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layout(location = 0) out vec2 outUV;
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void main() {
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vec2 pos;
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vec2 uv;
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if (gl_VertexIndex == 0) {
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pos = vec2(-1.0, -1.0);
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uv = vec2(0.0, 0.0);
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} else if (gl_VertexIndex == 1) {
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pos = vec2(1.0, -1.0);
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uv = vec2(1.0, 0.0);
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} else if (gl_VertexIndex == 2) {
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pos = vec2(-1.0, 1.0);
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uv = vec2(0.0, 1.0);
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} else { // gl_VertexIndex == 3
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pos = vec2(1.0, 1.0);
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uv = vec2(1.0, 1.0);
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}
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gl_Position = vec4(pos, 0.0, 1.0);
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outUV = uv;
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} |