Files
tactileipc3d/shaders/heatmap.frag
2026-01-20 23:41:46 +08:00

64 lines
1.7 KiB
GLSL

#version 330 core
in vec2 vUV;
in vec3 vWorldPos;
out vec4 FragColor;
uniform sampler2D uHeightTex;
uniform float uMinV;
uniform float uMaxV;
uniform float uHeightScale;
uniform vec2 uTexelSize;
uniform vec2 uPlaneSize;
uniform vec3 uCameraPos;
uniform vec3 uLightDir;
uniform vec3 uColorLow;
uniform vec3 uColorMid;
uniform vec3 uColorHigh;
float saturate(float x) { return clamp(x, 0.0, 1.0); }
float value01(float v) {
return saturate((v - uMinV) / max(uMaxV - uMinV, 1e-6));
}
vec3 colorRamp(float t) {
if (t < 0.5) {
return mix(uColorLow, uColorMid, t / 0.5);
}
return mix(uColorMid, uColorHigh, (t - 0.5) / 0.5);
}
void main() {
float vC = texture(uHeightTex, vUV).r;
float t = value01(vC);
vec3 base = colorRamp(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);
}