27 lines
634 B
GLSL
27 lines
634 B
GLSL
#version 330 core
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in vec3 direction;
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out vec4 frag_color;
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uniform sampler2D equirect;
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const vec2 inv_atan = vec2(0.15915494309, 0.31830988618);
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vec2 sample_spherical_map(vec3 v) {
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vec2 uv = vec2(atan(v.z, v.x), asin(clamp(v.y, -1.0, 1.0)));
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uv *= inv_atan;
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uv += 0.5;
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uv.x = fract(uv.x);
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return uv;
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}
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void main() {
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vec2 uv = sample_spherical_map(normalize(direction));
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uv.y = 1.0 - uv.y;
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vec2 size = vec2(textureSize(equirect, 0));
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float epsY = 0.5 / max(size.y, 1.0);
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uv.y = clamp(uv.y, epsY, 1.0 - epsY);
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vec3 color = texture(equirect, uv).rgb;
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frag_color = vec4(color, 1.0);
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}
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