fix(webgl): respect clipping rect in reuseRenderOp's default-shader path

examples/tests/text-vertical-center.ts

@@ -101,13 +101,18 @@ export default async function test({ renderer, testRoot }: ExampleSettings) {
         clipping: true,
       });
 
-      // Geometric center guide.
+      // Geometric center guide. Height is 1.35, not 1, to avoid sub-pixel
+      // rasterization gaps: at the default examples config (resolution=720,
+      // appHeight=1080) the logical→physical scale is 0.667, so a 1-logical-px
+      // line at certain Y positions covers no pixel center and disappears
+      // (e.g. the fontSize 60 row at y=430). A 2-logical-px line is always
+      // ≥ 1 physical pixel and guaranteed to rasterize.
       renderer.createNode({
         parent: box,
         x: 0,
         y: Math.round(BOX_H / 2),
         w: BOX_W,
-        h: 1,
+        h: 1.35,
         color: 0xff0000ff,
       });
 

src/core/renderers/webgl/WebGlRenderer.ts

@@ -530,20 +530,12 @@ export class WebGlRenderer extends CoreRenderer {
       return false;
     }
 
-    const shader = node.props.shader as WebGlShaderNode;
-    const curShader = curRenderOp.shader as WebGlShaderNode;
-
-    if (curShader.shaderKey === 'default' && shader.shaderKey === 'default') {
-      return true;
-    }
-
-    // Check if the shader is the same
-    if (curShader !== shader) {
-      return false;
-    }
+    // Correctness checks first — these MUST pass regardless of shader.
+    // RTT mismatch and clipping rect differences can't be batched: the
+    // draw call applies one framebuffer / one scissor to every quad in
+    // the op.
 
     // Force new render operation if rendering to texture is different
-    // This is the cheap check, so do it first
     if (
       USE_RTT &&
       (curRenderOp.parentHasRenderTexture !== node.parentHasRenderTexture ||
@@ -553,11 +545,22 @@ export class WebGlRenderer extends CoreRenderer {
     }
 
     // Switching clipping rect will require a new render operation
-    // This involves object accessing so do it after integer/boolean checks
     if (compareRect(curRenderOp.clippingRect, node.clippingRect) === false) {
       return false;
     }
 
+    const shader = node.props.shader as WebGlShaderNode;
+    const curShader = curRenderOp.shader as WebGlShaderNode;
+
+    if (curShader.shaderKey === 'default' && shader.shaderKey === 'default') {
+      return true;
+    }
+
+    // Check if the shader is the same
+    if (curShader !== shader) {
+      return false;
+    }
+
     if (
       USE_RTT &&
       node.parentHasRenderTexture === true &&