Orkuncakilkaya
eee6a0906e
terpage.glsl is the reference block (tpSlot, tpUV, terHeight, terHeightSmooth, terNormalXZ, terOrtho, tpOrthoRes, tpOrthoLod), pasted by section into terrain.vert, terrain.frag, tersun.frag, model.vert, grass.vert and grass.mesh. u_tp_on = 0 reads the old samplers with the old coordinates and filtering; on, a resident tile is read at level 0 from u_tp_h / u_tp_nrm / u_tp_ortho, anything else from the coarse map now bound under the old names. The B-splines use the FULL map's texel and take every tap through the page, so a tile edge stays one surface; blurred photograph reads (lod 1-2.5) stay on u_ortho with the level moved down by the coarse map's ratio. The fragment stages drop their unused u_height. SPIR-V rebuilt: terrain programs carry 23 samplers (21 in the fragment stage), up from 19. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
85 lines
4 KiB
GLSL
85 lines
4 KiB
GLSL
// CDLOD terrain (Strugar 2009): every draw is one 32x32 patch of the quadtree, placed
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// and scaled by u_node. Toward the outer edge of its level's range each vertex morphs
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// onto the parent level's grid (odd vertices slide to their even neighbours), so a patch
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// meets its coarser neighbour edge-for-edge with no cracks and no popping. Height comes
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// from one B-spline sample of the height field at the morphed position, so every level
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// sits on the same continuous surface.
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layout(location = 0) in vec2 a_xz; // 0..1 across the patch
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uniform sampler2D u_height;
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uniform float u_half;
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uniform mat4 u_view;
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uniform mat4 u_proj;
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uniform vec2 u_origin;
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uniform vec3 u_cam_pos;
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uniform vec3 u_node; // x0, z0, size (m)
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uniform vec2 u_morph; // distance where the morph starts, and where it is complete
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uniform float u_grid; // cells per patch side
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#define TP_HMAP u_height
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// terpage.glsl, pasted (the reference copy and its rules are there)
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// ---- the page table ----------------------------------------------------------------------
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#ifndef TP_HELPERS
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#define TP_HELPERS
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uniform sampler2D u_tp_page; // R32F, a texel a tile: slot + 1, 0 = not resident
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uniform float u_tp_on; // 1 while paging; 0 reads the whole maps exactly as before
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uniform vec4 u_tp_dims; // tiles a side, height texels a tile, photo texels a tile, full height res
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// the layer holding a full-map uv, or -1: paging off, off the map, or not resident
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float tpSlot(vec2 uv) {
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if (u_tp_on < 0.5 || uv.x < 0.0 || uv.y < 0.0 || uv.x >= 1.0 || uv.y >= 1.0) return -1.0;
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ivec2 t = min(ivec2(floor(uv * u_tp_dims.x)), ivec2(int(u_tp_dims.x) - 1));
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return texelFetch(u_tp_page, t, 0).r - 1.0;
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}
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// a full-map uv inside its tile's layer of k texels a side, past the one-texel border
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vec2 tpUV(vec2 uv, float k) { return (1.0 + fract(uv * u_tp_dims.x) * k) / (k + 2.0); }
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#endif
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// ---- height (vertex and mesh stages) -----------------------------------------------------
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#ifndef TP_HEIGHT
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#define TP_HEIGHT
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#ifndef TP_HMAP
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#define TP_HMAP u_ts_height
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#endif
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uniform sampler2DArray u_tp_h;
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// bilinear height, fine where a tile is resident. Outside a fragment stage texture() IS level 0
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// (glslang emits the same explicit-lod sample), so this is the old read bit for bit.
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float terHeight(vec2 uv) {
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float s = tpSlot(uv);
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if (s >= 0.0) return textureLod(u_tp_h, vec3(tpUV(uv, u_tp_dims.y), s), 0.0).r;
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return textureLod(TP_HMAP, uv, 0.0).r;
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}
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// The B-spline through four bilinear taps (heightSmooth). Paging on, the texel is the FULL
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// map's - the coarse map's own size would halve the surface's detail - and each tap finds its
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// own tile, so a patch straddling two tiles, or a tile and the coarse map, stays one surface.
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float terHeightSmooth(vec2 uv) {
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vec2 res = u_tp_on > 0.5 ? vec2(u_tp_dims.w) : vec2(textureSize(TP_HMAP, 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 (terHeight(vec2(o0.x, o0.y)) * s0.x + terHeight(vec2(o1.x, o0.y)) * s1.x) * s0.y
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+ (terHeight(vec2(o0.x, o1.y)) * s0.x + terHeight(vec2(o1.x, o1.y)) * s1.x) * s1.y;
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}
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#endif
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out vec3 v_wpos;
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out vec2 v_huv;
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void main() {
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vec2 grid = a_xz * u_grid;
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vec2 xz = u_node.xy + a_xz * u_node.z;
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vec2 huv = (xz - u_origin) / (2.0 * u_half) + 0.5;
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float h0 = terHeight(huv);
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float d = distance(vec3(xz.x, h0, xz.y), u_cam_pos);
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float k = clamp((d - u_morph.x) / max(u_morph.y - u_morph.x, 1.0), 0.0, 1.0);
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vec2 frac2 = fract(grid * 0.5) * 2.0; // 1 on odd vertices
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grid -= frac2 * k;
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xz = u_node.xy + grid / u_grid * u_node.z;
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huv = (xz - u_origin) / (2.0 * u_half) + 0.5;
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float h = terHeightSmooth(huv);
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vec3 p = vec3(xz.x, h, xz.y);
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v_wpos = p;
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v_huv = huv;
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gl_Position = u_proj * u_view * vec4(p, 1.0);
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}
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