29 lines
1020 B
GLSL
29 lines
1020 B
GLSL
#version 450 core
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struct PosColNorm { vec4 pos; vec4 dummy; };
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layout (std140, binding = 0) uniform TheMat { mat4 theMat; } ;
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layout (std140, binding = 1) uniform TheLight { vec4 lightPos; vec4 lumRad; };
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layout (std430, binding = 3) readonly buffer Data { PosColNorm data[]; };
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layout (std430, binding = 4) readonly buffer Indices { uint indices[]; };
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vec4 projNear (vec4 pos)
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{
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// note we project to a specific height
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// this is quite brittle, not ideal
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vec3 dir = pos.xyz - lightPos.xyz ;
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float a = (100 - pos.z) / dir.z ;
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vec2 xy = (pos.xyz + a * dir).xy ;
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return vec4 ( xy, 100 , 1) ;
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}
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bool ztest (vec4 p) {return p.z - lightPos.z > 0;}
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void main() {
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int j = gl_VertexID/3;
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int i1 = j * 3;
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vec4 po = data[indices[gl_VertexID]].pos;
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gl_Position = (po.w == 1
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&& ztest(data[indices[i1]].pos)
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&& ztest(data[indices[i1+1]].pos)
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&& ztest(data[indices[i1+2]].pos)
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? theMat * projNear(po)
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: vec4(1,1,1,0)
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);
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}
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