Orkuncakilkaya
1675eb451f
The first generation pass's R32F height is kept as ter_height_tex (not copied into an RGBA32F), so every reader of the height - placement, the read-back, physics, selftest16's 9 mm - sees the same 32 bits. ternormal.frag writes the baked normal's x and z into ter_normal_tex (RG16F), and the six places that read it (terrain.frag twice, tersun.frag, grass.vert, grass.mesh, grass_cull.comp, which takes a third texture at binding 6) rebuild y. SPIR-V regenerated. Maroon Lake's play, headless Vulkan: 2793 -> 2647 MB. The camp's frame: 0.066% of pixels differ by more than 8 (mean 0.024/255), isolated grass blades at the slope gate. ludic-dev test 307/307. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
32 lines
1.5 KiB
GLSL
32 lines
1.5 KiB
GLSL
// Second generation pass: bake the B-spline surface normal, once, at texel resolution: x and z
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// into an RG16F beside the R32F height (y is rebuilt where it is read). terrain.frag used to differentiate the bicubic height
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// per pixel — four bicubic reads, sixteen taps — for a quantity that never changes.
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in vec2 v_uv;
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out vec4 o;
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uniform sampler2D u_src;
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uniform float u_half;
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float heightSmooth(sampler2D tex, vec2 uv) {
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vec2 res = vec2(textureSize(tex, 0));
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vec2 t = uv * res - 0.5;
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vec2 f = fract(t);
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vec2 i = floor(t);
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vec2 w0 = (1.0 - f) * (1.0 - f) * (1.0 - f) / 6.0;
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vec2 w1 = (4.0 - 6.0 * f * f + 3.0 * f * f * f) / 6.0;
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vec2 w3 = f * f * f / 6.0;
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vec2 w2 = 1.0 - w0 - w1 - w3;
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vec2 s0 = w0 + w1, s1 = w2 + w3;
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vec2 o0 = (i - 1.0 + w1 / s0 + 0.5) / res;
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vec2 o1 = (i + 1.0 + w3 / s1 + 0.5) / res;
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return (texture(tex, vec2(o0.x, o0.y)).r * s0.x + texture(tex, vec2(o1.x, o0.y)).r * s1.x) * s0.y
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+ (texture(tex, vec2(o0.x, o1.y)).r * s0.x + texture(tex, vec2(o1.x, o1.y)).r * s1.x) * s1.y;
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}
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void main() {
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float step = 1.0 / float(textureSize(u_src, 0).x);
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float world = step * 2.0 * u_half;
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float hl = heightSmooth(u_src, v_uv - vec2(step, 0));
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float hr = heightSmooth(u_src, v_uv + vec2(step, 0));
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float hd = heightSmooth(u_src, v_uv - vec2(0, step));
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float hu = heightSmooth(u_src, v_uv + vec2(0, step));
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vec3 n = normalize(vec3(hl - hr, 2.0 * world, hd - hu));
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o = vec4(n.x, n.z, 0.0, 0.0); // into RG16F: x and z, y rebuilt when read (always up)
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}
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