27 lines
759 B
GLSL
27 lines
759 B
GLSL
#version 330 core
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// viewsize.x = viewport width in pixels; viewsize.y = viewport height in pixels
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uniform ivec2 viewsize;
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uniform ivec2 texturesize;
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// both position and and uv are in pixels, they where converted to floats when
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// passed to the shader
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layout(location = 0) in vec2 position;
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layout(location = 1) in vec2 txcoord;
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out vec2 uv;
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void main()
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{
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// matrix to change from image coordinates to opengl coordinates
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mat2 transform = mat2(vec2(0.0f, -1.0f), vec2(1.0f, 0.0f));
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vec2 v = vec2(float(viewsize.x), float(viewsize.y));
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vec2 h = v/2.0f;
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vec2 p = ((position-h)/ h);
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vec4 pos = vec4(p.x, p.y, 0.0f, 1.0f);
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gl_Position = pos;
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uv = vec2(txcoord.x / float(texturesize.x), (float(texturesize.y) - txcoord.y) / float(texturesize.y));
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}
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