62 lines
1.8 KiB
GLSL
62 lines
1.8 KiB
GLSL
#version 310 es
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#extension GL_EXT_tessellation_shader : require
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layout(quads, cw, fractional_even_spacing) in;
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layout(binding = 1, std140) uniform UBO
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{
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mat4 uMVP;
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vec4 uScale;
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vec2 uInvScale;
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vec3 uCamPos;
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vec2 uPatchSize;
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vec2 uInvHeightmapSize;
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} _31;
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layout(binding = 0) uniform mediump sampler2D uHeightmapDisplacement;
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in patch vec2 vOutPatchPosBase;
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in patch vec4 vPatchLods;
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out vec4 vGradNormalTex;
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out vec3 vWorld;
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vec2 lerp_vertex(vec2 tess_coord)
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{
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return (vOutPatchPosBase + (tess_coord * _31.uPatchSize));
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}
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mediump vec2 lod_factor(vec2 tess_coord)
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{
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mediump vec2 x = mix(vPatchLods.yx, vPatchLods.zw, vec2(tess_coord.x));
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mediump float level = mix(x.x, x.y, tess_coord.y);
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mediump float floor_level = floor(level);
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mediump float fract_level = (level - floor_level);
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return vec2(floor_level, fract_level);
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}
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mediump vec3 sample_height_displacement(vec2 uv, vec2 off, mediump vec2 lod)
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{
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return mix(textureLod(uHeightmapDisplacement, (uv + (off * 0.5)), lod.x).xyz, textureLod(uHeightmapDisplacement, (uv + (off * 1.0)), (lod.x + 1.0)).xyz, vec3(lod.y));
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}
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void main()
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{
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vec2 tess_coord = gl_TessCoord.xy;
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vec2 param = tess_coord;
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vec2 pos = lerp_vertex(param);
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vec2 param_1 = tess_coord;
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mediump vec2 lod = lod_factor(param_1);
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vec2 tex = (pos * _31.uInvHeightmapSize);
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pos = (pos * _31.uScale.xy);
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mediump float delta_mod = exp2(lod.x);
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vec2 off = (_31.uInvHeightmapSize * delta_mod);
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vGradNormalTex = vec4((tex + (_31.uInvHeightmapSize * 0.5)), (tex * _31.uScale.zw));
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vec2 param_2 = tex;
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vec2 param_3 = off;
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vec2 param_4 = lod;
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vec3 height_displacement = sample_height_displacement(param_2, param_3, param_4);
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pos = (pos + height_displacement.yz);
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vWorld = vec3(pos.x, height_displacement.x, pos.y);
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gl_Position = (_31.uMVP * vec4(vWorld, 1.0));
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}
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