Implement support for expanding crop rects in image filters

src/core/SkImageFilter.cpp

 /*
  * Copyright 2012 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkImageFilter.h"
 
 #include "SkBitmap.h"
+#include "SkDevice.h"
 #include "SkReadBuffer.h"
 #include "SkWriteBuffer.h"
 #include "SkRect.h"
 #include "SkValidationUtils.h"
 #if SK_SUPPORT_GPU
 #include "GrContext.h"
 #include "SkGrPixelRef.h"
 #include "SkGr.h"
 #endif
 
@@ skipping 127 matching lines @@
 #if SK_SUPPORT_GPU
     SkBitmap input = src;
     SkASSERT(fInputCount == 1);
     SkIPoint srcOffset = SkIPoint::Make(0, 0);
     if (this->getInput(0) &&
         !this->getInput(0)->getInputResultGPU(proxy, src, ctx, &input, &srcOffset)) {
         return false;
     }
     GrTexture* srcTexture = input.getTexture();
     SkIRect bounds;
-    src.getBounds(&bounds);
-    bounds.offset(srcOffset);
-    if (!this->applyCropRect(&bounds, ctx.ctm())) {
+    if (!this->applyCropRect(ctx, proxy, input, &srcOffset, &bounds, &input)) {
         return false;
     }
     SkRect srcRect = SkRect::Make(bounds);
     SkRect dstRect = SkRect::MakeWH(srcRect.width(), srcRect.height());
     GrContext* context = srcTexture->getContext();
 
     GrTextureDesc desc;
     desc.fFlags = kRenderTarget_GrTextureFlagBit,
     desc.fWidth = bounds.width();
     desc.fHeight = bounds.height();
@@ skipping 18 matching lines @@
     context->drawRectToRect(paint, dstRect, srcRect);
 
     SkAutoTUnref<GrTexture> resultTex(dst.detach());
     WrapTexture(resultTex, bounds.width(), bounds.height(), result);
     return true;
 #else
     return false;
 #endif
 }
 
-bool SkImageFilter::applyCropRect(SkIRect* rect, const SkMatrix& matrix) const {
+bool SkImageFilter::applyCropRect(const Context& ctx, const SkBitmap& src,
+                                  const SkIPoint& srcOffset, SkIRect* bounds) const {
+    SkIRect srcBounds;
+    src.getBounds(&srcBounds);
+    srcBounds.offset(srcOffset);
     SkRect cropRect;
-    matrix.mapRect(&cropRect, fCropRect.rect());
+    ctx.ctm().mapRect(&cropRect, fCropRect.rect());
     SkIRect cropRectI;
     cropRect.roundOut(&cropRectI);
     uint32_t flags = fCropRect.flags();
-    // If the original crop rect edges were unset, max out the new crop edges
-    if (!(flags & CropRect::kHasLeft_CropEdge)) cropRectI.fLeft = SK_MinS32;
-    if (!(flags & CropRect::kHasTop_CropEdge)) cropRectI.fTop = SK_MinS32;
-    if (!(flags & CropRect::kHasRight_CropEdge)) cropRectI.fRight = SK_MaxS32;
-    if (!(flags & CropRect::kHasBottom_CropEdge)) cropRectI.fBottom = SK_MaxS32;
-    return rect->intersect(cropRectI);
+    if (flags & CropRect::kHasLeft_CropEdge) srcBounds.fLeft = cropRectI.fLeft;
+    if (flags & CropRect::kHasTop_CropEdge) srcBounds.fTop = cropRectI.fTop;
+    if (flags & CropRect::kHasRight_CropEdge) srcBounds.fRight = cropRectI.fRight;
+    if (flags & CropRect::kHasBottom_CropEdge) srcBounds.fBottom = cropRectI.fBottom;
+    if (!srcBounds.intersect(ctx.clipBounds())) {
+        return false;
+    }
+    *bounds = srcBounds;
+    return true;
+}
+
+bool SkImageFilter::applyCropRect(const Context& ctx, Proxy* proxy, const SkBitmap& src,
+                                  SkIPoint* srcOffset, SkIRect* bounds, SkBitmap* dst) const {
+    SkIRect srcBounds;
+    src.getBounds(&srcBounds);
+    srcBounds.offset(*srcOffset);
+    SkRect cropRect;
+    ctx.ctm().mapRect(&cropRect, fCropRect.rect());
+    SkIRect cropRectI;
+    cropRect.roundOut(&cropRectI);
+    uint32_t flags = fCropRect.flags();
+    *bounds = srcBounds;
+    if (flags & CropRect::kHasLeft_CropEdge) bounds->fLeft = cropRectI.fLeft;
+    if (flags & CropRect::kHasTop_CropEdge) bounds->fTop = cropRectI.fTop;
+    if (flags & CropRect::kHasRight_CropEdge) bounds->fRight = cropRectI.fRight;
+    if (flags & CropRect::kHasBottom_CropEdge) bounds->fBottom = cropRectI.fBottom;
+    if (!bounds->intersect(ctx.clipBounds())) {
+        return false;
+    }
+    if (srcBounds.contains(*bounds)) {
+        *dst = src;
+        return true;
+    } else {
+        SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(bounds->width(), bounds->height()));
+        if (!device) {
+            return false;
+        }
+        SkCanvas canvas(device);
+        canvas.clear(0x00000000);
+        canvas.drawBitmap(src, srcOffset->x() - bounds->x(), srcOffset->y() - bounds->y());
+        *srcOffset = SkIPoint::Make(bounds->x(), bounds->y());
+        *dst = device->accessBitmap(false);
+        return true;
+    }
 }
 
 bool SkImageFilter::onFilterBounds(const SkIRect& src, const SkMatrix& ctm,
                                    SkIRect* dst) const {
     if (fInputCount < 1) {
         return false;
     }
 
     SkIRect bounds;
     for (int i = 0; i < fInputCount; ++i) {
@@ skipping 52 matching lines @@
                 result->setPixelRef(new SkGrPixelRef(info, resultTex))->unref();
                 GrUnlockAndUnrefCachedBitmapTexture(resultTex);
             }
             return true;
         } else {
             return false;
         }
     }
 }
 #endif