diff --git a/compositor.cm b/compositor.cm
index 2fa90ee3..d201beeb 100644
--- a/compositor.cm
+++ b/compositor.cm
@@ -221,7 +221,7 @@ function apply_effect(ctx, effect, input, params) {
     }
 
     // Blur passes
-    blur_passes = effect.blur_passes || 2
+    blur_passes = effect.blur_passes != null ? effect.blur_passes : 2
     blur_in = bright
     for (p = 0; p < blur_passes; p++) {
       ctx.passes[] = {type: 'shader_pass', shader: 'blur', input: blur_in, output: blur1, uniforms: {direction: {x: 1, y: 0}, texel_size: {x: 1/size.width, y: 1/size.height}}}
@@ -230,12 +230,13 @@ function apply_effect(ctx, effect, input, params) {
     }
     
     // Composite bloom
-    ctx.passes[] = {type: 'composite_textures', base: input, overlay: blur2, output: output, mode: 'add'}
+    ctx.passes[] = {type: 'composite_textures', base: input, overlay: blur_in, output: output, mode: 'add'}
     
   } else if (effect.type == 'mask') {
     mask_group = effect.mask_group
     // Query masks within the same plane to avoid cross-plane mask issues
     mask_sprites = film2d.query({group: mask_group, plane: current_plane})
+    log.compositor("mask effect: group=" + mask_group + " plane=" + current_plane + " sprites=" + text(length(mask_sprites)))
 
     if (length(mask_sprites) > 0) {
       mask_target = ctx.alloc(size.width, size.height, hint + '_mask')
diff --git a/film2d.cm b/film2d.cm
index 4316b91b..132527ce 100644
--- a/film2d.cm
+++ b/film2d.cm
@@ -176,13 +176,13 @@ film2d.unregister = function(id) {
 
 film2d.index_group = function(id, group) {
   if (!group_index[group]) group_index[group] = []
-  if (search(group_index[group], text(id)) == null)
+  if (find(group_index[group], text(id)) == null)
     group_index[group][] = text(id)
 }
 
 film2d.unindex_group = function(id, group) {
   if (!group_index[group]) return
-  var idx = search(group_index[group], text(id))
+  var idx = find(group_index[group], text(id))
   if (idx != null)
     group_index[group] = array(array(group_index[group], 0, idx), array(group_index[group], idx+1))
 }
@@ -218,7 +218,7 @@ film2d.query = function(selector) {
         // If also filtering by group, check membership
         if (selector.group) {
           groups = d.groups || []
-          if (search(groups, selector.group) != null) result[] = d
+          if (find(groups, selector.group) != null) result[] = d
         } else {
           result[] = d
         }
diff --git a/sdl_gpu.cm b/sdl_gpu.cm
index 11614d9e..7f1381cc 100644
--- a/sdl_gpu.cm
+++ b/sdl_gpu.cm
@@ -208,7 +208,7 @@ function _load_shaders() {
       stage: "fragment",
       format: "msl",
       entrypoint: "fragment_main",
-      num_uniform_buffers: 2,
+      num_uniform_buffers: 1,
       num_samplers: 2
     })
   }
@@ -452,20 +452,12 @@ function _create_pipelines() {
       target: {
         color_targets: [{
           format: _swapchain_format,
-          blend: {
-            enabled: true,
-            src_rgb: "src_alpha",
-            dst_rgb: "one_minus_src_alpha",
-            op_rgb: "add",
-            src_alpha: "one",
-            dst_alpha: "one_minus_src_alpha",
-            op_alpha: "add"
-          }
+          blend: {enabled: false}
         }]
       }
     })
   }
-  
+
   // CRT pipeline
   if (_blit_vert && _crt_frag) {
     _pipelines.crt =gpu_mod.graphics_pipeline(_gpu, {
@@ -2077,10 +2069,10 @@ function _do_mask(cmd_buffer, cmd) {
   var mode = cmd.mode || 'alpha'
   var invert = cmd.invert || false
   
-  if (!content || !content.texture) return
-  if (!mask || !mask.texture) return
-  if (!output || !output.texture) return
-  
+  if (!content || !content.texture) { log.graphics("mask: missing content texture"); return }
+  if (!mask || !mask.texture) { log.graphics("mask: missing mask texture"); return }
+  if (!output || !output.texture) { log.graphics("mask: missing output texture"); return }
+
   // Check if mask pipeline is available
   if (!_pipelines.mask) {
     log.console("sdl_gpu: Mask pipeline not available, falling back to blit")
diff --git a/shaders/msl/mask.frag.msl b/shaders/msl/mask.frag.msl
index 34120951..098057f1 100644
--- a/shaders/msl/mask.frag.msl
+++ b/shaders/msl/mask.frag.msl
@@ -35,6 +35,8 @@ fragment float4 fragment_main(
     mask_value = 1.0 - mask_value;
   }
   
-  // Apply mask to content alpha
-  return float4(content.rgb, content.a * mask_value);
+  // Content is premultiplied alpha from render pass blending.
+  // Un-premultiply before masking so downstream blit (src_alpha blend) works correctly.
+  float3 rgb = content.a > 0.001 ? content.rgb / content.a : float3(0);
+  return float4(rgb, content.a * mask_value);
 }