add multipass for faster blur

blueprints/.glsl/Image_Blur_1.frag

@@ -1,4 +1,5 @@
 #version 300 es
+#pragma passes 2
 precision highp float;
 
 // Blur type constants
@@ -14,6 +15,7 @@ uniform sampler2D u_image0;
 uniform vec2 u_resolution;
 uniform int u_int0;      // Blur type (BLUR_GAUSSIAN, BLUR_BOX, BLUR_RADIAL)
 uniform float u_float0;  // Blur radius/amount
+uniform int u_pass;      // Pass index (0 = horizontal, 1 = vertical)
 
 in vec2 v_texCoord;
 layout(location = 0) out vec4 fragColor0;
@@ -26,8 +28,14 @@ void main() {
     vec2 texelSize = 1.0 / u_resolution;
     float radius = max(u_float0, 0.0);
 
-    // Radial (angular) blur with incremental rotation
+    // Radial (angular) blur - single pass, doesn't use separable
     if (u_int0 == BLUR_RADIAL) {
+        // Only execute on first pass
+        if (u_pass > 0) {
+            fragColor0 = texture(u_image0, v_texCoord);
+            return;
+        }
+
         vec2 center = vec2(0.5);
         vec2 dir = v_texCoord - center;
         float dist = length(dir);
@@ -68,7 +76,7 @@ void main() {
         return;
     }
 
-    // Gaussian / Box blur (grid sampling)
+    // Separable Gaussian / Box blur
     int samples = int(ceil(radius));
 
     if (samples == 0) {
@@ -76,27 +84,27 @@ void main() {
         return;
     }
 
+    // Direction: pass 0 = horizontal, pass 1 = vertical
+    vec2 dir = (u_pass == 0) ? vec2(1.0, 0.0) : vec2(0.0, 1.0);
+
     vec4 color = vec4(0.0);
     float totalWeight = 0.0;
     float sigma = radius / 2.0;
 
-    for (int x = -samples; x <= samples; x++) {
-        for (int y = -samples; y <= samples; y++) {
-            vec2 offset = vec2(float(x), float(y)) * texelSize;
-            vec4 sample_color = texture(u_image0, v_texCoord + offset);
+    for (int i = -samples; i <= samples; i++) {
+        vec2 offset = dir * float(i) * texelSize;
+        vec4 sample_color = texture(u_image0, v_texCoord + offset);
 
-            float weight;
-            if (u_int0 == BLUR_GAUSSIAN) {
-                float dist = length(vec2(float(x), float(y)));
-                weight = gaussian(dist, sigma);
-            } else {
-                // BLUR_BOX
-                weight = 1.0;
-            }
-
-            color += sample_color * weight;
-            totalWeight += weight;
+        float weight;
+        if (u_int0 == BLUR_GAUSSIAN) {
+            weight = gaussian(float(i), sigma);
+        } else {
+            // BLUR_BOX
+            weight = 1.0;
         }
+
+        color += sample_color * weight;
+        totalWeight += weight;
     }
 
     fragColor0 = color / totalWeight;