GrCopySurfaceBatch

src/gpu/batches/GrCopySurfaceBatch.cpp

+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+
+#include "GrCopySurfaceBatch.h"
+
+// returns true if the read/written rect intersects the src/dst and false if not.
+static bool clip_srcrect_and_dstpoint(const GrSurface* dst,
+                                      const GrSurface* src,
+                                      const SkIRect& srcRect,
+                                      const SkIPoint& dstPoint,
+                                      SkIRect* clippedSrcRect,
+                                      SkIPoint* clippedDstPoint) {
+    *clippedSrcRect = srcRect;
+    *clippedDstPoint = dstPoint;
+
+    // clip the left edge to src and dst bounds, adjusting dstPoint if necessary
+    if (clippedSrcRect->fLeft < 0) {
+        clippedDstPoint->fX -= clippedSrcRect->fLeft;
+        clippedSrcRect->fLeft = 0;
+    }
+    if (clippedDstPoint->fX < 0) {
+        clippedSrcRect->fLeft -= clippedDstPoint->fX;
+        clippedDstPoint->fX = 0;
+    }
+
+    // clip the top edge to src and dst bounds, adjusting dstPoint if necessary
+    if (clippedSrcRect->fTop < 0) {
+        clippedDstPoint->fY -= clippedSrcRect->fTop;
+        clippedSrcRect->fTop = 0;
+    }
+    if (clippedDstPoint->fY < 0) {
+        clippedSrcRect->fTop -= clippedDstPoint->fY;
+        clippedDstPoint->fY = 0;
+    }
+
+    // clip the right edge to the src and dst bounds.
+    if (clippedSrcRect->fRight > src->width()) {
+        clippedSrcRect->fRight = src->width();
+    }
+    if (clippedDstPoint->fX + clippedSrcRect->width() > dst->width()) {
+        clippedSrcRect->fRight = clippedSrcRect->fLeft + dst->width() - clippedDstPoint->fX;
+    }
+
+    // clip the bottom edge to the src and dst bounds.
+    if (clippedSrcRect->fBottom > src->height()) {
+        clippedSrcRect->fBottom = src->height();
+    }
+    if (clippedDstPoint->fY + clippedSrcRect->height() > dst->height()) {
+        clippedSrcRect->fBottom = clippedSrcRect->fTop + dst->height() - clippedDstPoint->fY;
+    }
+
+    // The above clipping steps may have inverted the rect if it didn't intersect either the src or
+    // dst bounds.
+    return !clippedSrcRect->isEmpty();
+}
+
+GrBatch* GrCopySurfaceBatch::Create(GrSurface* dst, GrSurface* src, const SkIRect& srcRect,
+                                    const SkIPoint& dstPoint) {
+    SkASSERT(dst);
+    SkASSERT(src);
+
+    SkIRect clippedSrcRect;
+    SkIPoint clippedDstPoint;
+    // If the rect is outside the src or dst then we've already succeeded.
+    if (!clip_srcrect_and_dstpoint(dst,
+                                    src,
+                                    srcRect,
+                                    dstPoint,
+                                    &clippedSrcRect,
+                                    &clippedDstPoint)) {
+        return NULL;
+    }
+    return SkNEW_ARGS(GrCopySurfaceBatch, (dst, src, clippedSrcRect, clippedDstPoint));
+}