update

main.cpp

@@ -215,6 +215,10 @@ private:
         glBindVertexArray(0);
     }
 
+    void initHeatmapGeometry_() {
+
+    }
+
     bool initBgProgram() {
         auto vshader = std::make_unique<LOpenGLShader>(LOpenGLShader::ShaderType::Vertex);
         auto fshader = std::make_unique<LOpenGLShader>(LOpenGLShader::ShaderType::Fragment);
@@ -275,6 +279,12 @@ private:
         return true;
     }
 
+    bool initHeatmapProgram() {
+        auto vshader = std::make_unique<LOpenGLShader>(LOpenGLShader::ShaderType::Vertex);
+        auto fshader = std::make_unique<LOpenGLShader>(LOpenGLShader::ShaderType::Fragment);
+        
+    }
+
     void drawBg() {
         if (!bgProg_ || !bgVao_ || !bgVbo_) {
             std::cout << "check !bgProg_ || !bgVao_ || !bgVbo_ failed\n";
@@ -291,7 +301,7 @@ private:
         glBindVertexArray(0);
 
         glEnable(GL_DEPTH_TEST);
-    }
+    }   
 
     void drawPanel() {
         if (!panelProg_ || !panelVao_ || !panelVbo_ || !panelIbo_) {
@@ -435,6 +445,11 @@ private:
     float panelHeight_ = 0.35;
     float panelDepth_ = 0.05;
 
+    std::unique_ptr<LOpenGLProgram> heatmapProg_;
+    std::string heatmapVertShaderPath_;
+    std::string heatmapFragShaderPath_;
+    unsigned int heatmapVao_ = 0;
+    unsigned int heatmapVbo_ = 0;
 
     ViewPort viewport_{800, 600};
     Camera camera_{glm::vec3(0.0f, 0.0f, 2.0f)};

shader/heatmap.frag

@@ -62,41 +62,37 @@ float maxNeighborValue(vec2 uv) {
     return max(max(v00, v10), max(v01, v11));
 }
 
-float maxNeighborValue3(vec2 uv) {
-    vec2 texSizeF = 1.0 / uTexelSize;
+ivec2 texSizeI(vec2 texelSize) {
+    vec2 texSizeF = 1.0 / texelSize;
     ivec2 texSizeI = ivec2(max(vec2(1.0), floor(texSizeF + 0.5)));
-    ivec2 maxCoord = texSizeI - ivec2(1);
+    return texSizeI;
+}
 
-    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);
+ivec2 uvToTexel(vec2 uv, vec2 texelSize) {
+    ivec2 sizeI = texSizeI(texelSize);
+    ivec2 maxCoord = sizeI - ivec2(1);
+    vec2 texelF =  clamp(uv * vec2(maxCoord), vec2(0.0), vec2(maxCoord));
+    return ivec2(floor(texelF));
+}
 
-    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 maxNeighborValueK(vec2 uv, int radius) {
+    radius = clamp(radius, 0, 4);
+    ivec2 sizeI = texSizeI(uTexelSize);
+    ivec2 maxCoord = sizeI - ivec2(1);
+    ivec2 p = uvToTexel(uv, uTexelSize);
 
-    float max1020 = max(v10, v20);
-    float max0111 = max(v01, v11);
-    float max2102 = max(v21, v02);
-    float max1222 = max(v12, v22);
+    float vmax = -1e30;
 
-    float fmax1 = max(max1020, max0111);
-    float fmax2 = max(max2102, max1222);
+    for (int i = -4; i <= 4; ++i) {
+        for (int j = -4; j <= 4; ++j) {
+            if (abs(i) > radius || abs(j) > radius) continue;
+            ivec2 c = clamp(p + ivec2(i, j), ivec2(0), maxCoord);
+            float v = texelFetch(uHeightTex, c, 0).r;
+            vmax = max(vmax, v);
+        }
+    }
 
-    return max(v00, max(fmax1, fmax2));
+    return vmax;
 }
 
 vec3 colorRamp(float t) {