using real tiles when simulating tiling

samplecode/SampleApp.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "SampleApp.h"
 
 #include "SkData.h"
 #include "SkCanvas.h"
 #include "SkDevice.h"
 #include "SkGraphics.h"
 #include "SkImageDecoder.h"
 #include "SkImageEncoder.h"
 #include "SkPaint.h"
 #include "SkPicture.h"
 #include "SkPictureRecorder.h"
 #include "SkStream.h"
+#include "SkSurface.h"
 #include "SkTSort.h"
 #include "SkTime.h"
 #include "SkWindow.h"
 
 #include "SampleCode.h"
 #include "SkTypeface.h"
 
 #if SK_SUPPORT_GPU
 #include "gl/GrGLInterface.h"
 #include "gl/GrGLUtil.h"
@@ skipping 1156 matching lines @@
                 this->INHERITED::draw(canvas);
             }
         }
 
         SkBitmap diff;
         if (bitmap_diff(canvas, orig, &diff)) {
         }
     } else {
         SkSize tile = this->tileSize();
 
-        for (SkScalar y = 0; y < height(); y += tile.height()) {
-            for (SkScalar x = 0; x < width(); x += tile.width()) {
-                SkAutoCanvasRestore acr(canvas, true);
-                canvas->clipRect(SkRect::MakeXYWH(x, y,
-                                                  tile.width(),
-                                                  tile.height()));
-                this->INHERITED::draw(canvas);
+        if (kNo_Tiling == fTilingMode) {
+            this->INHERITED::draw(canvas); // no looping or surfaces needed
+        } else {
+            const int w = SkScalarRoundToInt(tile.width());
+            const int h = SkScalarRoundToInt(tile.height());
+            SkImageInfo info = SkImageInfo::MakeN32Premul(w, h);
+            SkAutoTUnref<SkSurface> surface(canvas->newSurface(info));
+            SkCanvas* tileCanvas = surface->getCanvas();
+
+            for (SkScalar y = 0; y < height(); y += tile.height()) {
+                for (SkScalar x = 0; x < width(); x += tile.width()) {
+                    SkAutoCanvasRestore acr(tileCanvas, true);
+                    tileCanvas->translate(-x, -y);
+                    tileCanvas->clear(0);
+                    this->INHERITED::draw(tileCanvas);
+                    surface->draw(canvas, x, y, NULL);
+                }
             }
-        }
 
-        if (fTilingMode != kNo_Tiling) {
+            // for drawing the borders between tiles
             SkPaint paint;
             paint.setColor(0x60FF00FF);
             paint.setStyle(SkPaint::kStroke_Style);
 
             for (SkScalar y = 0; y < height(); y += tile.height()) {
                 for (SkScalar x = 0; x < width(); x += tile.width()) {
-                    canvas->drawRect(SkRect::MakeXYWH(x, y,
-                                                      tile.width(),
-                                                      tile.height()),
-                                     paint);
+                    canvas->drawRect(SkRect::MakeXYWH(x, y, tile.width(), tile.height()), paint);
                 }
             }
         }
     }
     if (fShowZoomer && !fSaveToPdf) {
         showZoomer(canvas);
     }
     if (fMagnify && !fSaveToPdf) {
         magnify(canvas);
     }
@@ skipping 1332 matching lines @@
     SkGraphics::Init();
     SkEvent::Init();
 }
 
 // FIXME: this should be in a header
 void application_term();
 void application_term() {
     SkEvent::Term();
     SkGraphics::Term();
 }