26 lines
876 B
GLSL
26 lines
876 B
GLSL
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#version 330 core
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out vec3 cubemap_coord0;
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out vec3 cubemap_coord1;
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out vec3 cubemap_coord2;
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out vec3 cubemap_coord3;
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out vec3 cubemap_coord4;
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out vec3 cubemap_coord5;
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void main()
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{
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vec2 pos = vec2(gl_VertexID % 2, gl_VertexID / 2) * 4.0 - 1.0;
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gl_Position = vec4(pos, 0.0, 1.0);
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// Map the quad texture coordinates to a direction vector to sample
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// the cubemap. This assumes that we are using the weird left-handed
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// orientations given by the OpenGL spec.
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// See https://www.khronos.org/opengl/wiki/Cubemap_Texture#Upload_and_orientation
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cubemap_coord0 = vec3( 1.0, -pos.y, -pos.x);
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cubemap_coord1 = vec3(- 1.0, -pos.y, pos.x);
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cubemap_coord2 = vec3( pos.x, 1.0, pos.y);
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cubemap_coord3 = vec3( pos.x, - 1.0, -pos.y);
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cubemap_coord4 = vec3( pos.x, -pos.y, 1.0);
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cubemap_coord5 = vec3(-pos.x, -pos.y, - 1.0);
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}
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