update

shader/heatmap.frag

@@ -24,4 +24,130 @@ float value01(float v) {
     return saturate((v - uMinV) / max(uMaxV - uMinV, 1e-6));
 }
 
-float maxNeighborValue(vec2 uv)
+// float maxNeighborValue(vec2 uv) {
+//     vec2 texSizeF = 1.0 / uTexelSize;
+//     ivec2 texSizeI = ivec2(max(vec2(1.0), floor(texSizeF + 0.5)));
+//     ivec2 maxCoord = texSizeI - ivec2(1);
+
+//     vec2 texelF = clamp(uv * texSizeF, vec2(0.0), vec2(maxCoord));
+//     ivec2 base = ivec2(floor(texelF));
+//     ivec2 base10 = min(base + ivec2(1, 0), maxCoord);
+//     ivec2 base01 = min(base + ivec2(0, 1), maxCoord);
+//     ivec2 base11 = min(base + ivec2(1, 1), maxCoord);
+
+//     float v00 = texelFetch(uHeightTex, base, 0).r;
+//     float v10 = texelFetch(uHeightTex, base10, 0).r;
+//     float v01 = texelFetch(uHeightTex, base01, 0).r;
+//     float v11 = texelFetch(uHeightTex, base11, 0).r;
+
+//     return max(max(v00, v10), max(v01, v11));
+// }
+
+float maxNeighborValue(vec2 uv) {
+    vec2 texSizeF = 1.0 / uTexelSize;
+    ivec2 texSizeI = ivec2(max(vec2(1.0), floor(texSizeF + 0.5)));
+    ivec2 maxCoord = texSizeI - ivec2(1);
+
+    vec2 texelF = clamp(uv * texSizeF, vec2(0.0), vec2(maxCoord));
+    ivec2 base = ivec2(floor(texelF));
+    ivec2 base10 = min(base + ivec2(1, 0), maxCoord);
+    ivec2 base01 = min(base + ivec2(0, 1), maxCoord);
+    ivec2 base11 = min(base + ivec2(1, 1), maxCoord);
+
+    float v00 = texelFetch(uHeightTex, base, 0).r;
+    float v10 = texelFetch(uHeightTex, base10, 0).r;
+    float v01 = texelFetch(uHeightTex, base01, 0).r;
+    float v11 = texelFetch(uHeightTex, base11, 0).r;
+
+    return max(max(v00, v10), max(v01, v11));
+}
+
+float maxNeighborValue3(vec2 uv) {
+    vec2 texSizeF = 1.0 / uTexelSize;
+    ivec2 texSizeI = ivec2(max(vec2(1.0), floor(texSizeF + 0.5)));
+    ivec2 maxCoord = texSizeI - ivec2(1);
+
+    vec2 texelF = clamp(uv * texSizeF, vec2(0.0), vec2(maxCoord));
+    ivec2 base = ivec2(floor(texelF));
+    ivec2 base10 = min(base + ivec2(1, 0), maxCoord);
+    ivec2 base20 = min(base + ivec2(2, 0), maxCoord);
+    ivec2 base01 = min(base + ivec2(0, 1), maxCoord);
+    ivec2 base11 = min(base + ivec2(1, 1), maxCoord);
+    ivec2 base21 = min(base + ivec2(2, 1), maxCoord);
+    ivec2 base02 = min(base + ivec2(0, 2), maxCoord);
+    ivec2 base12 = min(base + ivec2(1, 2), maxCoord);
+    ivec2 base22 = min(base + ivec2(2, 2), maxCoord);
+
+    float v00 = texelFetch(uHeightTex, base, 0).r;
+    float v10 = texelFetch(uHeightTex, base10, 0).r;
+    float v20 = texelFetch(uHeightTex, base20, 0).r;
+    float v01 = texelFetch(uHeightTex, base01, 0).r;
+    float v11 = texelFetch(uHeightTex, base11, 0).r;
+    float v21 = texelFetch(uHeightTex, base21, 0).r;
+    float v02 = texelFetch(uHeightTex, base02, 0).r;
+    float v12 = texelFetch(uHeightTex, base12, 0).r;
+    float v22 = texelFetch(uHeightTex, base22, 0).r;
+
+    float max1020 = max(v10, v20);
+    float max0111 = max(v01, v11);
+    float max2102 = max(v21, v02);
+    float max1222 = max(v12, v22);
+
+    float fmax1 = max(max1020, max0111);
+    float fmax2 = max(max2102, max1222);
+
+    return max(v00, max(fmax1, fmax2));
+}
+
+vec3 colorRamp(float t) {
+    if (t < 0.5) {
+        return mix(uColorLow, uColorMid, t / 0.5);
+    }
+    return mix(uColorMid, uColorHigh, (t - 0.5) / 0.5);
+}
+
+vec3 colorRampWithZero(float t) {
+    const float zeroW = 0.005;
+    float blend = smoothstep(0.0, zeroW, t);
+    float tRamp = saturate((t - zeroW) / max(1.0 - zeroW, 1e-6));
+    vec3 ramp = colorRamp(tRamp);
+    return mix(uColorZero, ramp, blend);
+}
+
+void main() {
+    float vC = texture(uHeightTex, vUV).r;
+    bool isZero = abs(vC) <= 1e-6;
+    float t = value01(vC);
+    float m = maxNeighborValue(vUV);
+    float eps = max(1e-4, 0.001 * (uMaxV - uMinV));
+    float force = smoothstep(uMaxV - eps, uMaxV, m);
+    t = max(t, force);
+    vec3 base = isZero ? uColorZero : colorRampWithZero(t);
+
+    float vL = texture(uHeightTex, vUV - vec2(uTexelSize.x, 0.0)).r;
+    float vR = texture(uHeightTex, vUV + vec2(uTexelSize.x, 0.0)).r;
+    float vD = texture(uHeightTex, vUV - vec2(0.0, uTexelSize.y)).r;
+    float vU = texture(uHeightTex, vUV + vec2(0.0, uTexelSize.y)).r;
+
+    float hL = value01(vL) * uHeightScale;
+    float hR = value01(vR) * uHeightScale;
+    float hD = value01(vD) * uHeightScale;
+    float hU = value01(vU) * uHeightScale;
+
+    float dx = max(1e-6, uPlaneSize.x * uTexelSize.x);
+    float dy = max(1e-6, uPlaneSize.y * uTexelSize.y);
+    float dHx = (hR - hL) / (2.0 * dx);
+    float dHy = (hU - hD) / (2.0 * dy);
+
+    vec3 N = normalize(vec3(-dHx, -dHy, -1.0));
+    vec3 L = normalize(uLightDir);
+    vec3 V = normalize(uCameraPos - vWorldPos);
+    vec3 H = normalize(L + V);
+
+    float diff = saturate(dot(N, L));
+    float spec = pow(saturate(dot(N, H)), 24.0);
+
+    vec3 col = base * (0.50 + 0.50 * diff);
+    col += vec3(1.0) * spec * 0.18;
+    FragColor = vec4(clamp(col, 0.0, 1.0), 1.0);
+}