WIP RasterCanvasLayerAllocator experiment 2

skia/ext/bitmap_platform_device_cairo.cc

-// Copyright 2013 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 "build/build_config.h"
-#include "skia/ext/bitmap_platform_device_cairo.h"
-#include "skia/ext/platform_canvas.h"
-
-#if defined(OS_OPENBSD)
-#include <cairo.h>
-#else
-#include <cairo/cairo.h>
-#endif
-
-namespace skia {
-
-namespace {
-
-void CairoSurfaceReleaseProc(void*, void* context) {
-  SkASSERT(context);
-  cairo_surface_destroy(static_cast<cairo_surface_t*>(context));
-}
-
-// Back the destination bitmap by a Cairo surface.  The bitmap's
-// pixelRef takes ownership of the passed-in surface and will call
-// cairo_surface_destroy() upon destruction.
-//
-// Note: it may immediately destroy the surface, if it fails to create a bitmap
-// with pixels, thus the caller must either ref() the surface before hand, or
-// it must not refer to the surface after this call.
-bool InstallCairoSurfacePixels(SkBitmap* dst,
-                               cairo_surface_t* surface,
-                               bool is_opaque) {
-  SkASSERT(dst);
-  if (!surface) {
-    return false;
-  }
-  SkImageInfo info
-      = SkImageInfo::MakeN32(cairo_image_surface_get_width(surface),
-                             cairo_image_surface_get_height(surface),
-                             is_opaque ? kOpaque_SkAlphaType
-                                       : kPremul_SkAlphaType);
-  return dst->installPixels(info,
-                            cairo_image_surface_get_data(surface),
-                            cairo_image_surface_get_stride(surface),
-                            NULL,
-                            &CairoSurfaceReleaseProc,
-                            static_cast<void*>(surface));
-}
-
-void LoadMatrixToContext(cairo_t* context, const SkMatrix& matrix) {
-  cairo_matrix_t cairo_matrix;
-  cairo_matrix_init(&cairo_matrix,
-                    SkScalarToFloat(matrix.getScaleX()),
-                    SkScalarToFloat(matrix.getSkewY()),
-                    SkScalarToFloat(matrix.getSkewX()),
-                    SkScalarToFloat(matrix.getScaleY()),
-                    SkScalarToFloat(matrix.getTranslateX()),
-                    SkScalarToFloat(matrix.getTranslateY()));
-  cairo_set_matrix(context, &cairo_matrix);
-}
-
-void LoadClipToContext(cairo_t* context, const SkIRect& clip_bounds) {
-  cairo_reset_clip(context);
-
-  cairo_rectangle(context, clip_bounds.fLeft, clip_bounds.fTop,
-                  clip_bounds.width(), clip_bounds.height());
-  cairo_clip(context);
-}
-
-}  // namespace
-
-void BitmapPlatformDevice::LoadConfig(const SkMatrix& transform,
-                                      const SkIRect& clip_bounds) {
-  if (!cairo_)
-    return;  // Nothing to do.
-
-  LoadClipToContext(cairo_, clip_bounds);
-  LoadMatrixToContext(cairo_, transform);
-}
-
-// We use this static factory function instead of the regular constructor so
-// that we can create the pixel data before calling the constructor. This is
-// required so that we can call the base class' constructor with the pixel
-// data.
-BitmapPlatformDevice* BitmapPlatformDevice::Create(int width, int height,
-                                                   bool is_opaque,
-                                                   cairo_surface_t* surface) {
-  if (cairo_surface_status(surface) != CAIRO_STATUS_SUCCESS) {
-    cairo_surface_destroy(surface);
-    return NULL;
-  }
-
-  // must call this before trying to install the surface, since that may result
-  // in the surface being destroyed.
-  cairo_t* cairo = cairo_create(surface);
-
-  SkBitmap bitmap;
-  if (!InstallCairoSurfacePixels(&bitmap, surface, is_opaque)) {
-    cairo_destroy(cairo);
-    return NULL;
-  }
-
-  // The device object will take ownership of the graphics context.
-  return new BitmapPlatformDevice(bitmap, cairo);
-}
-
-BitmapPlatformDevice* BitmapPlatformDevice::Create(int width, int height,
-                                                   bool is_opaque) {
-  // This initializes the bitmap to all zeros.
-  cairo_surface_t* surface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32,
-                                                        width, height);
-
-  BitmapPlatformDevice* device = Create(width, height, is_opaque, surface);
-
-#ifndef NDEBUG
-    if (device && is_opaque)  // Fill with bright bluish green
-        SkCanvas(device).drawColor(0xFF00FF80);
-#endif
-
-  return device;
-}
-
-BitmapPlatformDevice* BitmapPlatformDevice::Create(int width, int height,
-                                                   bool is_opaque,
-                                                   uint8_t* data) {
-  cairo_surface_t* surface = cairo_image_surface_create_for_data(
-      data, CAIRO_FORMAT_ARGB32, width, height,
-      cairo_format_stride_for_width(CAIRO_FORMAT_ARGB32, width));
-
-  return Create(width, height, is_opaque, surface);
-}
-
-// Ownership of the cairo object is transferred.
-BitmapPlatformDevice::BitmapPlatformDevice(
-    const SkBitmap& bitmap,
-    cairo_t* cairo)
-    : SkBitmapDevice(bitmap),
-      cairo_(cairo) {
-  SetPlatformDevice(this, this);
-}
-
-BitmapPlatformDevice::~BitmapPlatformDevice() {
-  cairo_destroy(cairo_);
-}
-
-SkBaseDevice* BitmapPlatformDevice::onCreateDevice(const CreateInfo& info,
-                                                   const SkPaint*) {
-  SkASSERT(info.fInfo.colorType() == kN32_SkColorType);
-  return BitmapPlatformDevice::Create(info.fInfo.width(), info.fInfo.height(),
-                                      info.fInfo.isOpaque());
-}
-
-cairo_t* BitmapPlatformDevice::BeginPlatformPaint(
-      const SkMatrix& transform,
-      const SkIRect& clip_bounds) {
-  LoadConfig(transform, clip_bounds);
-  cairo_surface_t* surface = cairo_get_target(cairo_);
-  // Tell cairo to flush anything it has pending.
-  cairo_surface_flush(surface);
-  // Tell Cairo that we (probably) modified (actually, will modify) its pixel
-  // buffer directly.
-  cairo_surface_mark_dirty(surface);
-  return cairo_;
-}
-
-// PlatformCanvas impl
-
-SkCanvas* CreatePlatformCanvas(int width, int height, bool is_opaque,
-                               uint8_t* data, OnFailureType failureType) {
-  sk_sp<SkBaseDevice> dev(
-      BitmapPlatformDevice::Create(width, height, is_opaque, data));
-  return CreateCanvas(dev, failureType);
-}
-
-}  // namespace skia