add compute shader to auto calculate screen exposure, add SSBO impl

Editor/assets/shaders/Exposure.glsl

@@ -0,0 +1,63 @@
+#type compute
+#version 460 core
+layout(local_size_x = 1, local_size_y = 1) in;
+
+layout(binding = 0, std430) buffer Histogram {
+    uint bins[64];
+};
+layout(binding = 1, std430) buffer Exposure {
+    float exposure;
+};
+
+uniform float u_SpeedUp;
+uniform float u_SpeedDown;
+uniform float u_Key;
+uniform float u_LowPercent;
+uniform float u_HighPercent;
+uniform float u_MinExposure;
+uniform float u_MaxExposure;
+uniform float u_DeltaTime;
+uniform float u_LogMin;
+uniform float u_LogMax;
+
+void main() {
+    float currentExposure = exposure;
+
+    uint total = 0;
+    uint prefix[64];
+    for (int i = 0; i < 64; i++) {
+        total += bins[i];
+        prefix[i] = total;
+    }
+
+    float lowCount = u_LowPercent * 0.01 * total;
+    float highCount = u_HighPercent * 0.01 * total;
+    int lowBin = 0, highBin = 63;
+    for (int i = 0; i < 64; i++) {
+        if (prefix[i] < lowCount) lowBin = i + 1;
+        if (prefix[i] < highCount) highBin = i + 1;
+    }
+    lowBin = clamp(lowBin, 0, 63);
+    highBin = clamp(highBin, 0, 63);
+
+    float sumLum = 0.0;
+    uint count = 0;
+    for (int i = lowBin; i <= highBin; i++) {
+        float t = (float(i) + 0.5) / 64.0;
+        float logLum = u_LogMin + t * (u_LogMax - u_LogMin);
+        float lum = exp2(logLum);
+        sumLum += lum * float(bins[i]);
+        count += bins[i];
+    }
+    float avgLum = count > 0 ? sumLum / count : 0.18;
+
+    float targetExposure = u_Key / max(avgLum, 0.0001);
+    targetExposure = clamp(targetExposure, u_MinExposure, u_MaxExposure);
+
+    float speed = (targetExposure > currentExposure) ? u_SpeedUp : u_SpeedDown;
+    float adaptFactor = 1.0 - exp(-speed * u_DeltaTime);
+    float newExposure = mix(currentExposure, targetExposure, adaptFactor);
+    newExposure = clamp(newExposure, u_MinExposure, u_MaxExposure);
+
+    exposure = newExposure;
+}