Add platform_canvas_unittest.cc

Also fixes issue 2977.
Review URL: http://codereview.chromium.org/5644

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@2777 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 58 insertions, 39 deletions

diff --git a/base/base.xcodeproj/project.pbxproj b/base/base.xcodeproj/project.pbxproj
index b8db42e..51ace0b 100644
--- a/base/base.xcodeproj/project.pbxproj
+++ b/base/base.xcodeproj/project.pbxproj
@@ -162,6 +162,7 @@
 		ABF4B9BE0DC2BD1500A6E319 /* sha512.cc in Sources */ = {isa = PBXBuildFile; fileRef = 825403700D92D2840006B936 /* sha512.cc */; };
 		ABF4B9C30DC2BD6C00A6E319 /* values.cc in Sources */ = {isa = PBXBuildFile; fileRef = 825403880D92D2CF0006B936 /* values.cc */; };
 		ABFBD3E60DC793C600E164CB /* md5.cc in Sources */ = {isa = PBXBuildFile; fileRef = 825403290D92D2090006B936 /* md5.cc */; };
+		B5EF235C0E89ABF500E1E114 /* platform_canvas_unittest.cc in Sources */ = {isa = PBXBuildFile; fileRef = ABE1BA0C0E756EC4009041DA /* platform_canvas_unittest.cc */; };
 		BA0F69870E79D7980079A8A1 /* thread_local_storage_unittest.cc in Sources */ = {isa = PBXBuildFile; fileRef = BA0F69860E79D7980079A8A1 /* thread_local_storage_unittest.cc */; };
 		BA5CC5840E788093004EDD45 /* shared_memory_unittest.cc in Sources */ = {isa = PBXBuildFile; fileRef = BA5CC5830E788093004EDD45 /* shared_memory_unittest.cc */; };
 		BA739A020E5E3242009842A7 /* tracked_objects_unittest.cc in Sources */ = {isa = PBXBuildFile; fileRef = BA739A000E5E3242009842A7 /* tracked_objects_unittest.cc */; };
@@ -1432,6 +1433,7 @@
 				7B78D3950E54FE0100609465 /* observer_list_unittest.cc in Sources */,
 				7B78D3960E54FE0100609465 /* path_service_unittest.cc in Sources */,
 				7B78D3970E54FE0100609465 /* pickle_unittest.cc in Sources */,
+				B5EF235C0E89ABF500E1E114 /* platform_canvas_unittest.cc in Sources */,
 				A5CB82980E5C74E300FD6825 /* platform_test_mac.mm in Sources */,
 				7B8505D50E5B441000730B43 /* png_codec_unittest.cc in Sources */,
 				7B78D3980E54FE0100609465 /* pr_time_unittest.cc in Sources */,
diff --git a/base/gfx/bitmap_platform_device_mac.cc b/base/gfx/bitmap_platform_device_mac.cc
index 40b58cf..570b07e 100755
--- a/base/gfx/bitmap_platform_device_mac.cc
+++ b/base/gfx/bitmap_platform_device_mac.cc
@@ -130,7 +130,6 @@ void BitmapPlatformDeviceMac::BitmapPlatformDeviceMacData::LoadConfig() {
   // Transform.
   SkMatrix t(transform_);
   LoadTransformToCGContext(bitmap_context_, t);
-  
   t.setTranslateX(-t.getTranslateX());
   t.setTranslateY(-t.getTranslateY());
   LoadClippingRegionToCGContext(bitmap_context_, clip_region_, t);
@@ -145,15 +144,18 @@ BitmapPlatformDeviceMac* BitmapPlatformDeviceMac::Create(CGContextRef context,
                                                          int width,
                                                          int height,
                                                          bool is_opaque) {
-  // TODO(playmobil): remove debug code.
-  //printf("BitmapPlatformDeviceMac::Create(%d,%d)\n", width, height);
-  // each pixel is 4 bytes (RGBA):
   void* data = malloc(height * width * 4);
   if (!data) return NULL;
 
   SkBitmap bitmap;
   bitmap.setConfig(SkBitmap::kARGB_8888_Config, width, height);
   bitmap.setPixels(data);
+  
+  // Note: The Windows implementation clears the Bitmap later on.
+  // This bears mentioning since removal of this line makes the
+  // unit tests only fail periodically (or when MallocPreScribble is set).
+  bitmap.eraseARGB(0, 0, 0, 0);
+  
   bitmap.setIsOpaque(is_opaque);
 
   if (is_opaque) {
@@ -170,7 +172,8 @@ BitmapPlatformDeviceMac* BitmapPlatformDeviceMac::Create(CGContextRef context,
   CGContextRef bitmap_context =
     CGBitmapContextCreate(data, width, height, 8, width*4,
                           color_space, kCGImageAlphaPremultipliedLast);
-  // change the coordinate system to match WebCore's
+  
+  // Change the coordinate system to match WebCore's
   CGContextTranslateCTM(bitmap_context, 0, height);
   CGContextScaleCTM(bitmap_context, 1.0, -1.0);
   CGColorSpaceRelease(color_space);
diff --git a/base/gfx/platform_canvas_unittest.cc b/base/gfx/platform_canvas_unittest.cc
index 81e5c75..8e227ad 100644
--- a/base/gfx/platform_canvas_unittest.cc
+++ b/base/gfx/platform_canvas_unittest.cc
@@ -78,8 +78,10 @@ void DrawNativeRect(PlatformCanvas& canvas, int x, int y, int w, int h) {
   CGContextRef context = canvas.beginPlatformPaint();
   
   CGRect inner_rc = CGRectMake(x, y, w, h);
-  CGFloat black[] = { 0.0, 0.0, 0.0, 1.0 };  // RGBA opaque black
-  CGContextSetFillColor(context, black);
+  // RGBA opaque black
+  CGColorRef black = CGColorCreateGenericRGB(0.0, 0.0, 0.0, 1.0);
+  CGContextSetFillColorWithColor(context, black);
+  CGColorRelease(black);
   CGContextFillRect(context, inner_rc);
   
   canvas.endPlatformPaint();
diff --git a/base/gfx/platform_device_mac.cc b/base/gfx/platform_device_mac.cc
index ab0b188..93909f1 100755
--- a/base/gfx/platform_device_mac.cc
+++ b/base/gfx/platform_device_mac.cc
@@ -97,37 +97,32 @@ void PlatformDeviceMac::LoadPathToCGContext(CGContextRef context,
 // static
 void PlatformDeviceMac::LoadTransformToCGContext(CGContextRef context,
                                                  const SkMatrix& matrix) {
-  // TODO: CoreGraphics can concatenate transforms, but not reset the current
-  // one.  Either find a workaround or remove this function if it turns out
-  // to be unneeded on the Mac.
-  // For now, just load the translation.
+  // CoreGraphics can concatenate transforms, but not reset the current one.
+  // So in order to get the required behavior here, we need to first make
+  // the current transformation matrix identity and only then load the new one.
   
-  // First reset the Transforms.
-  // TODO(playmobil): no need to call CGContextTranslateCTM() twice
-  // just add up the numbers and call through.
-  CGAffineTransform orig_transform = CGContextGetCTM(context);
-  CGContextTranslateCTM(context,
-                        -orig_transform.tx,
-                        orig_transform.ty);  // y axis is flipped.
-
-  // TODO(playmobil): remove debug code.
-  // CGAffineTransform temp_transform = CGContextGetCTM(context);
+  // Reset matrix to identity.
+  CGAffineTransform orig_cg_matrix = CGContextGetCTM(context);
+  CGAffineTransform orig_cg_matrix_inv = CGAffineTransformInvert(orig_cg_matrix);
+  CGContextConcatCTM(context, orig_cg_matrix_inv);
+  
+  // assert that we have indeed returned to the identity Matrix.
+  DCHECK(CGAffineTransformIsIdentity(CGContextGetCTM(context)));
+  
+  // Convert xform to CG-land.
+  // Our coordinate system is flipped to match WebKit's so we need to modify
+  // the xform to match that.
+  SkMatrix transformed_matrix = matrix;
+  SkScalar sy = matrix.getScaleY() * (SkScalar)-1;
+  transformed_matrix.setScaleY(sy);
+  size_t height = CGBitmapContextGetHeight(context);
+  SkScalar ty = -matrix.getTranslateY(); // y axis is flipped.
+  transformed_matrix.setTranslateY(ty + (SkScalar)height);
+  
+  CGAffineTransform cg_matrix = SkMatrixToCGAffineTransform(transformed_matrix);
   
-  // Now set the new transform.
-  int tx = matrix.getTranslateX();
-  int ty = -matrix.getTranslateY();
-  int height = CGBitmapContextGetHeight(context);
-  CGContextTranslateCTM(context,
-                        tx,
-                        -(ty+height));
-  CGAffineTransform new_transform = CGContextGetCTM(context);
-// TODO(playmobil): remove debug code.
-//  printf("tx_matrix (%lf,%lf)->(%lf,%lf)->(%lf,%lf) (%d, %d) height=%d\n", orig_transform.tx,
-//                                       orig_transform.ty,
-//                                       foo_transform.tx,
-//                                       foo_transform.ty,
-//                                       new_transform.tx,
-//                                       new_transform.ty, tx, ty, height);
+  // Load final transform into context.
+  CGContextConcatCTM(context, cg_matrix);
 }
 
 // static
@@ -147,9 +142,6 @@ void PlatformDeviceMac::LoadClippingRegionToCGContext(
     transformation.mapRect(&rect);
     SkIRect irect;
     rect.round(&irect);
-// TODO(playmobil): remove debug code.
-//    printf("Clipping to (%d,%d) (%d,%d)\n", irect.fLeft, irect.fTop, 
-//           irect.fRight, irect.fBottom);
     CGContextClipToRect(context, SkIRectToCGRect(irect));
   } else {
     // It is complex.
diff --git a/base/gfx/skia_utils_mac.cc b/base/gfx/skia_utils_mac.cc
index d9ccb3f..b5962c3 100644
--- a/base/gfx/skia_utils_mac.cc
+++ b/base/gfx/skia_utils_mac.cc
@@ -5,10 +5,26 @@
 #include "base/gfx/skia_utils_mac.h"
 
 #include "base/logging.h"
+#include "SkMatrix.h"
 #include "SkRect.h"
 
 namespace gfx {
 
+CGAffineTransform SkMatrixToCGAffineTransform(const SkMatrix& matrix) {
+  // CGAffineTransforms don't support perspective transforms, so make sure
+  // we don't get those.
+  DCHECK(matrix[SkMatrix::kMPersp0] == 0.0f);
+  DCHECK(matrix[SkMatrix::kMPersp1] == 0.0f);
+  DCHECK(matrix[SkMatrix::kMPersp2] == 1.0f);
+  
+  return CGAffineTransformMake(matrix[SkMatrix::kMScaleX],
+                               matrix[SkMatrix::kMSkewY],
+                               matrix[SkMatrix::kMSkewX],
+                               matrix[SkMatrix::kMScaleY],
+                               matrix[SkMatrix::kMTransX],
+                               matrix[SkMatrix::kMTransY]);
+}
+  
 SkIRect CGRectToSkIRect(const CGRect& rect) {
   SkIRect sk_rect = {
     SkScalarRound(rect.origin.x),
diff --git a/base/gfx/skia_utils_mac.h b/base/gfx/skia_utils_mac.h
index c1419c2..a99905f 100644
--- a/base/gfx/skia_utils_mac.h
+++ b/base/gfx/skia_utils_mac.h
@@ -9,6 +9,7 @@
 #include "SkColor.h"
 #include <CoreGraphics/CGColor.h>
 
+struct SkMatrix;
 struct SkIRect;
 struct SkPoint;
 struct SkRect;
@@ -26,6 +27,9 @@ inline const CGPoint& SkPointToCGPoint(const SkPoint& point) {
 inline const SkPoint& CGPointToSkPoint(const CGPoint& point) {
   return reinterpret_cast<const SkPoint&>(point);
 }
+
+// Matrix converters.
+CGAffineTransform SkMatrixToCGAffineTransform(const SkMatrix& matrix);
   
 // Rectangle converters.
 SkRect CGRectToSkRect(const CGRect& rect);