skia/ext/platform_device_win.cc - chromium/src - Git at Google

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #include "skia/ext/platform_device.h"

 #include "skia/ext/skia_utils_win.h"
 #include "third_party/skia/include/core/SkMatrix.h"
 #include "third_party/skia/include/core/SkPath.h"
 #include "third_party/skia/include/core/SkRegion.h"
 #include "third_party/skia/include/core/SkUtils.h"

 namespace skia {

 void InitializeDC(HDC context) {
   // Enables world transformation.
   // If the GM_ADVANCED graphics mode is set, GDI always draws arcs in the
   // counterclockwise direction in logical space. This is equivalent to the
   // statement that, in the GM_ADVANCED graphics mode, both arc control points
   // and arcs themselves fully respect the device context's world-to-device
   // transformation.
   BOOL res = SetGraphicsMode(context, GM_ADVANCED);
   SkASSERT(res != 0);

   // Enables dithering.
   res = SetStretchBltMode(context, HALFTONE);
   SkASSERT(res != 0);
   // As per SetStretchBltMode() documentation, SetBrushOrgEx() must be called
   // right after.
   res = SetBrushOrgEx(context, 0, 0, NULL);
   SkASSERT(res != 0);

   // Sets up default orientation.
   res = SetArcDirection(context, AD_CLOCKWISE);
   SkASSERT(res != 0);

   // Sets up default colors.
   res = SetBkColor(context, RGB(255, 255, 255));
   SkASSERT(res != CLR_INVALID);
   res = SetTextColor(context, RGB(0, 0, 0));
   SkASSERT(res != CLR_INVALID);
   res = SetDCBrushColor(context, RGB(255, 255, 255));
   SkASSERT(res != CLR_INVALID);
   res = SetDCPenColor(context, RGB(0, 0, 0));
   SkASSERT(res != CLR_INVALID);

   // Sets up default transparency.
   res = SetBkMode(context, OPAQUE);
   SkASSERT(res != 0);
   res = SetROP2(context, R2_COPYPEN);
   SkASSERT(res != 0);
 }

 PlatformSurface PlatformDevice::BeginPlatformPaint() {
   return 0;
 }

 void PlatformDevice::EndPlatformPaint() {
   // We don't clear the DC here since it will be likely to be used again.
   // Flushing will be done in onAccessBitmap.
 }

 void PlatformDevice::DrawToNativeContext(PlatformSurface surface, int x, int y,
                                          const PlatformRect* src_rect) {
 }

 // static
 bool PlatformDevice::LoadPathToDC(HDC context, const SkPath& path) {
   switch (path.getFillType()) {
     case SkPath::kWinding_FillType: {
       int res = SetPolyFillMode(context, WINDING);
       SkASSERT(res != 0);
       break;
     }
     case SkPath::kEvenOdd_FillType: {
       int res = SetPolyFillMode(context, ALTERNATE);
       SkASSERT(res != 0);
       break;
     }
     default: {
       SkASSERT(false);
       break;
     }
   }
   BOOL res = BeginPath(context);
   if (!res) {
       return false;
   }

   CubicPaths paths;
   if (!SkPathToCubicPaths(&paths, path))
     return false;

   std::vector<POINT> points;
   for (CubicPaths::const_iterator path(paths.begin()); path != paths.end();
        ++path) {
     if (!path->size())
       continue;
     points.resize(0);
     points.reserve(path->size() * 3 / 4 + 1);
     points.push_back(SkPointToPOINT(path->front().p[0]));
     for (CubicPath::const_iterator point(path->begin()); point != path->end();
        ++point) {
       // Never add point->p[0]
       points.push_back(SkPointToPOINT(point->p[1]));
       points.push_back(SkPointToPOINT(point->p[2]));
       points.push_back(SkPointToPOINT(point->p[3]));
     }
     SkASSERT((points.size() - 1) % 3 == 0);
     // This is slightly inefficient since all straight line and quadratic lines
     // are "upgraded" to a cubic line.
     // TODO(maruel):  http://b/1147346 We should use
     // PolyDraw/PolyBezier/Polyline whenever possible.
     res = PolyBezier(context, &points.front(),
                      static_cast<DWORD>(points.size()));
     SkASSERT(res != 0);
     if (res == 0)
       break;
   }
   if (res == 0) {
     // Make sure the path is discarded.
     AbortPath(context);
   } else {
     res = EndPath(context);
     SkASSERT(res != 0);
   }
   return true;
 }

 // static
 void PlatformDevice::LoadTransformToDC(HDC dc, const SkMatrix& matrix) {
   XFORM xf;
   xf.eM11 = matrix[SkMatrix::kMScaleX];
   xf.eM21 = matrix[SkMatrix::kMSkewX];
   xf.eDx = matrix[SkMatrix::kMTransX];
   xf.eM12 = matrix[SkMatrix::kMSkewY];
   xf.eM22 = matrix[SkMatrix::kMScaleY];
   xf.eDy = matrix[SkMatrix::kMTransY];
   SetWorldTransform(dc, &xf);
 }

 // static
 bool PlatformDevice::SkPathToCubicPaths(CubicPaths* paths,
                                         const SkPath& skpath) {
   paths->clear();
   CubicPath* current_path = NULL;
   SkPoint current_points[4];
   CubicPoints points_to_add;
   SkPath::Iter iter(skpath, false);
   for (SkPath::Verb verb = iter.next(current_points);
        verb != SkPath::kDone_Verb;
        verb = iter.next(current_points)) {
     switch (verb) {
       case SkPath::kMove_Verb: {  // iter.next returns 1 point
         // Ignores it since the point is copied in the next operation. See
         // SkPath::Iter::next() for reference.
         paths->push_back(CubicPath());
         current_path = &paths->back();
         // Skip point addition.
         continue;
       }
       case SkPath::kLine_Verb: {  // iter.next returns 2 points
         points_to_add.p[0] = current_points[0];
         points_to_add.p[1] = current_points[0];
         points_to_add.p[2] = current_points[1];
         points_to_add.p[3] = current_points[1];
         break;
       }
       case SkPath::kQuad_Verb: {  // iter.next returns 3 points
         points_to_add.p[0] = current_points[0];
         points_to_add.p[1] = current_points[1];
         points_to_add.p[2] = current_points[2];
         points_to_add.p[3] = current_points[2];
         break;
       }
       case SkPath::kCubic_Verb: {  // iter.next returns 4 points
         points_to_add.p[0] = current_points[0];
         points_to_add.p[1] = current_points[1];
         points_to_add.p[2] = current_points[2];
         points_to_add.p[3] = current_points[3];
         break;
       }
       case SkPath::kClose_Verb: {  // iter.next returns 1 point (the last point)
         paths->push_back(CubicPath());
         current_path = &paths->back();
         continue;
       }
       default: {
         current_path = NULL;
         // Will return false.
         break;
       }
     }
     SkASSERT(current_path);
     if (!current_path) {
       paths->clear();
       return false;
     }
     current_path->push_back(points_to_add);
   }
   return true;
 }

 // static
 void PlatformDevice::LoadClippingRegionToDC(HDC context,
                                             const SkRegion& region,
                                             const SkMatrix& transformation) {
   HRGN hrgn;
   if (region.isEmpty()) {
     // region can be empty, in which case everything will be clipped.
     hrgn = CreateRectRgn(0, 0, 0, 0);
   } else if (region.isRect()) {
     // We don't apply transformation, because the translation is already applied
     // to the region.
     hrgn = CreateRectRgnIndirect(&SkIRectToRECT(region.getBounds()));
   } else {
     // It is complex.
     SkPath path;
     region.getBoundaryPath(&path);
     // Clip. Note that windows clipping regions are not affected by the
     // transform so apply it manually.
     // Since the transform is given as the original translation of canvas, we
     // should apply it in reverse.
     SkMatrix t(transformation);
     t.setTranslateX(-t.getTranslateX());
     t.setTranslateY(-t.getTranslateY());
     path.transform(t);
     LoadPathToDC(context, path);
     hrgn = PathToRegion(context);
   }
   int result = SelectClipRgn(context, hrgn);
   SkASSERT(result != ERROR);
   result = DeleteObject(hrgn);
   SkASSERT(result != 0);
 }

 }  // namespace skia
	// Copyright (c) 2012 The Chromium Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#include "skia/ext/platform_device.h"

	#include "skia/ext/skia_utils_win.h"
	#include "third_party/skia/include/core/SkMatrix.h"
	#include "third_party/skia/include/core/SkPath.h"
	#include "third_party/skia/include/core/SkRegion.h"
	#include "third_party/skia/include/core/SkUtils.h"

	namespace skia {

	void InitializeDC(HDC context) {
	// Enables world transformation.
	// If the GM_ADVANCED graphics mode is set, GDI always draws arcs in the
	// counterclockwise direction in logical space. This is equivalent to the
	// statement that, in the GM_ADVANCED graphics mode, both arc control points
	// and arcs themselves fully respect the device context's world-to-device
	// transformation.
	BOOL res = SetGraphicsMode(context, GM_ADVANCED);
	SkASSERT(res != 0);

	// Enables dithering.
	res = SetStretchBltMode(context, HALFTONE);
	SkASSERT(res != 0);
	// As per SetStretchBltMode() documentation, SetBrushOrgEx() must be called
	// right after.
	res = SetBrushOrgEx(context, 0, 0, NULL);
	SkASSERT(res != 0);

	// Sets up default orientation.
	res = SetArcDirection(context, AD_CLOCKWISE);
	SkASSERT(res != 0);

	// Sets up default colors.
	res = SetBkColor(context, RGB(255, 255, 255));
	SkASSERT(res != CLR_INVALID);
	res = SetTextColor(context, RGB(0, 0, 0));
	SkASSERT(res != CLR_INVALID);
	res = SetDCBrushColor(context, RGB(255, 255, 255));
	SkASSERT(res != CLR_INVALID);
	res = SetDCPenColor(context, RGB(0, 0, 0));
	SkASSERT(res != CLR_INVALID);

	// Sets up default transparency.
	res = SetBkMode(context, OPAQUE);
	SkASSERT(res != 0);
	res = SetROP2(context, R2_COPYPEN);
	SkASSERT(res != 0);
	}

	PlatformSurface PlatformDevice::BeginPlatformPaint() {
	return 0;
	}

	void PlatformDevice::EndPlatformPaint() {
	// We don't clear the DC here since it will be likely to be used again.
	// Flushing will be done in onAccessBitmap.
	}

	void PlatformDevice::DrawToNativeContext(PlatformSurface surface, int x, int y,
	const PlatformRect* src_rect) {
	}

	// static
	bool PlatformDevice::LoadPathToDC(HDC context, const SkPath& path) {
	switch (path.getFillType()) {
	case SkPath::kWinding_FillType: {
	int res = SetPolyFillMode(context, WINDING);
	SkASSERT(res != 0);
	break;
	}
	case SkPath::kEvenOdd_FillType: {
	int res = SetPolyFillMode(context, ALTERNATE);
	SkASSERT(res != 0);
	break;
	}
	default: {
	SkASSERT(false);
	break;
	}
	}
	BOOL res = BeginPath(context);
	if (!res) {
	return false;
	}

	CubicPaths paths;
	if (!SkPathToCubicPaths(&paths, path))
	return false;

	std::vector<POINT> points;
	for (CubicPaths::const_iterator path(paths.begin()); path != paths.end();
	++path) {
	if (!path->size())
	continue;
	points.resize(0);
	points.reserve(path->size() * 3 / 4 + 1);
	points.push_back(SkPointToPOINT(path->front().p[0]));
	for (CubicPath::const_iterator point(path->begin()); point != path->end();
	++point) {
	// Never add point->p[0]
	points.push_back(SkPointToPOINT(point->p[1]));
	points.push_back(SkPointToPOINT(point->p[2]));
	points.push_back(SkPointToPOINT(point->p[3]));
	}
	SkASSERT((points.size() - 1) % 3 == 0);
	// This is slightly inefficient since all straight line and quadratic lines
	// are "upgraded" to a cubic line.
	// TODO(maruel): http://b/1147346 We should use
	// PolyDraw/PolyBezier/Polyline whenever possible.
	res = PolyBezier(context, &points.front(),
	static_cast<DWORD>(points.size()));
	SkASSERT(res != 0);
	if (res == 0)
	break;
	}
	if (res == 0) {
	// Make sure the path is discarded.
	AbortPath(context);
	} else {
	res = EndPath(context);
	SkASSERT(res != 0);
	}
	return true;
	}

	// static
	void PlatformDevice::LoadTransformToDC(HDC dc, const SkMatrix& matrix) {
	XFORM xf;
	xf.eM11 = matrix[SkMatrix::kMScaleX];
	xf.eM21 = matrix[SkMatrix::kMSkewX];
	xf.eDx = matrix[SkMatrix::kMTransX];
	xf.eM12 = matrix[SkMatrix::kMSkewY];
	xf.eM22 = matrix[SkMatrix::kMScaleY];
	xf.eDy = matrix[SkMatrix::kMTransY];
	SetWorldTransform(dc, &xf);
	}

	// static
	bool PlatformDevice::SkPathToCubicPaths(CubicPaths* paths,
	const SkPath& skpath) {
	paths->clear();
	CubicPath* current_path = NULL;
	SkPoint current_points[4];
	CubicPoints points_to_add;
	SkPath::Iter iter(skpath, false);
	for (SkPath::Verb verb = iter.next(current_points);
	verb != SkPath::kDone_Verb;
	verb = iter.next(current_points)) {
	switch (verb) {
	case SkPath::kMove_Verb: { // iter.next returns 1 point
	// Ignores it since the point is copied in the next operation. See
	// SkPath::Iter::next() for reference.
	paths->push_back(CubicPath());
	current_path = &paths->back();
	// Skip point addition.
	continue;
	}
	case SkPath::kLine_Verb: { // iter.next returns 2 points
	points_to_add.p[0] = current_points[0];
	points_to_add.p[1] = current_points[0];
	points_to_add.p[2] = current_points[1];
	points_to_add.p[3] = current_points[1];
	break;
	}
	case SkPath::kQuad_Verb: { // iter.next returns 3 points
	points_to_add.p[0] = current_points[0];
	points_to_add.p[1] = current_points[1];
	points_to_add.p[2] = current_points[2];
	points_to_add.p[3] = current_points[2];
	break;
	}
	case SkPath::kCubic_Verb: { // iter.next returns 4 points
	points_to_add.p[0] = current_points[0];
	points_to_add.p[1] = current_points[1];
	points_to_add.p[2] = current_points[2];
	points_to_add.p[3] = current_points[3];
	break;
	}
	case SkPath::kClose_Verb: { // iter.next returns 1 point (the last point)
	paths->push_back(CubicPath());
	current_path = &paths->back();
	continue;
	}
	default: {
	current_path = NULL;
	// Will return false.
	break;
	}
	}
	SkASSERT(current_path);
	if (!current_path) {
	paths->clear();
	return false;
	}
	current_path->push_back(points_to_add);
	}
	return true;
	}

	// static
	void PlatformDevice::LoadClippingRegionToDC(HDC context,
	const SkRegion& region,
	const SkMatrix& transformation) {
	HRGN hrgn;
	if (region.isEmpty()) {
	// region can be empty, in which case everything will be clipped.
	hrgn = CreateRectRgn(0, 0, 0, 0);
	} else if (region.isRect()) {
	// We don't apply transformation, because the translation is already applied
	// to the region.
	hrgn = CreateRectRgnIndirect(&SkIRectToRECT(region.getBounds()));
	} else {
	// It is complex.
	SkPath path;
	region.getBoundaryPath(&path);
	// Clip. Note that windows clipping regions are not affected by the
	// transform so apply it manually.
	// Since the transform is given as the original translation of canvas, we
	// should apply it in reverse.
	SkMatrix t(transformation);
	t.setTranslateX(-t.getTranslateX());
	t.setTranslateY(-t.getTranslateY());
	path.transform(t);
	LoadPathToDC(context, path);
	hrgn = PathToRegion(context);
	}
	int result = SelectClipRgn(context, hrgn);
	SkASSERT(result != ERROR);
	result = DeleteObject(hrgn);
	SkASSERT(result != 0);
	}

	} // namespace skia