clear out texture on first batch. This fixes aliasing artifacts due to incorrect blending of old texture

Author: martinfouilleul

samples/clock/src/main.c

@@ -112,35 +112,35 @@ ORCA_EXPORT void oc_on_frame_refresh(void)
 
         oc_vec2 pos = oc_mat2x3_mul(transform, (oc_vec2){ clockRadius * 0.8f, 0 });
 
-        oc_set_color_rgba(0.2, 0.2, 0.2, 1);
+        oc_set_color_srgba(0.2, 0.2, 0.2, 1);
         oc_text_fill(pos.x, pos.y, clockNumberStrings[i]);
     }
 
     // hours hand
     oc_matrix_multiply_push(mat_transform(centerX, centerY, hoursRotation));
     {
-        oc_set_color_rgba(.2, 0.2, 0.2, 1);
+        oc_set_color_srgba(.2, 0.2, 0.2, 1);
         oc_rounded_rectangle_fill(0, -7.5 * uiScale, clockRadius * 0.5f, 15 * uiScale, 5 * uiScale);
     }
     oc_matrix_pop();
 
     // minutes hand
     oc_matrix_multiply_push(mat_transform(centerX, centerY, minutesRotation));
     {
-        oc_set_color_rgba(.2, 0.2, 0.2, 1);
+        oc_set_color_srgba(.2, 0.2, 0.2, 1);
         oc_rounded_rectangle_fill(0, -5 * uiScale, clockRadius * 0.7f, 10 * uiScale, 5 * uiScale);
     }
     oc_matrix_pop();
 
     // seconds hand
     oc_matrix_multiply_push(mat_transform(centerX, centerY, secondsRotation));
     {
-        oc_set_color_rgba(1, 0.2, 0.2, 1);
+        oc_set_color_srgba(1, 0.2, 0.2, 1);
         oc_rounded_rectangle_fill(0, -2.5 * uiScale, clockRadius * 0.8f, 5 * uiScale, 5 * uiScale);
     }
     oc_matrix_pop();
 
-    oc_set_color_rgba(.2, 0.2, 0.2, 1);
+    oc_set_color_srgba(.2, 0.2, 0.2, 1);
     oc_circle_fill(centerX, centerY, 10 * uiScale);
 
     oc_canvas_render(renderer, context, surface);

src/graphics/wgpu_renderer.c

@@ -3327,7 +3327,32 @@ void oc_wgpu_canvas_submit(oc_canvas_renderer_base* rendererBase,
             }
 
             //----------------------------------------------------------------------------------------
-            //NOTE: clear texture
+            //NOTE: clear out texture if this is the first batch
+            if(batchCount == 0)
+            {
+                //clear out texture
+                WGPURenderPassDescriptor desc = {
+                    .colorAttachmentCount = 1,
+                    .colorAttachments = (WGPURenderPassColorAttachment[]){
+                        {
+                            .view = renderer->outTextureView,
+                            .depthSlice = WGPU_DEPTH_SLICE_UNDEFINED,
+                            .loadOp = WGPULoadOp_Clear,
+                            .storeOp = WGPUStoreOp_Store,
+                            .clearValue = { 0, 0, 0, 0 },
+                        },
+                    },
+                };
+
+                WGPURenderPassEncoder pass = wgpuCommandEncoderBeginRenderPass(encoder, &desc);
+                {
+                    wgpuRenderPassEncoderSetViewport(pass, 0.f, 0.f, screenSize.x, screenSize.y, 0.f, 1.f);
+                }
+                wgpuRenderPassEncoderEnd(pass);
+            }
+
+            //----------------------------------------------------------------------------------------
+            //NOTE: clear batch texture
             {
                 WGPURenderPassDescriptor desc = {
                     .colorAttachmentCount = 1,

tests/perf/build.sh

@@ -15,4 +15,4 @@ install_name_tool -add_rpath "@executable_path" $BINDIR/driver
 
 cp Info.plist $BINDIR/
 cp $LIBDIR/liborca.dylib $BINDIR/
-cp $SRCDIR/ext/dawn/bin/libwebgpu.dylib $BINDIR/
+cp $LIBDIR/libwebgpu.dylib $BINDIR/