skia2/tools/sk_app/ios/RasterWindowContext_ios.cpp
Brian Osman 6848b716f7 Fix flicker when changing backend on iOS viewer
This is the same fix from: https://skia-review.googlesource.com/c/skia/+/107941

Change-Id: I1367b1fc466cecbc2733b4e337376ce9f48cb6d8
Reviewed-on: https://skia-review.googlesource.com/107980
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2018-02-16 15:31:36 +00:00

128 lines
3.8 KiB
C++

/*
* Copyright 2017 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include <OpenGLES/ES2/gl.h>
#include "../GLWindowContext.h"
#include "SDL.h"
#include "SkCanvas.h"
#include "SkColorFilter.h"
#include "WindowContextFactory_ios.h"
#include "gl/GrGLInterface.h"
#include "sk_tool_utils.h"
using sk_app::DisplayParams;
using sk_app::window_context_factory::IOSWindowInfo;
using sk_app::GLWindowContext;
namespace {
// We use SDL to support Mac windowing mainly for convenience's sake. However, it
// does not allow us to support a purely raster backend because we have no hooks into
// the NSWindow's drawRect: method. Hence we use GL to handle the update. Should we
// want to avoid this, we will probably need to write our own windowing backend.
class RasterWindowContext_ios : public GLWindowContext {
public:
RasterWindowContext_ios(const IOSWindowInfo&, const DisplayParams&);
~RasterWindowContext_ios() override;
sk_sp<SkSurface> getBackbufferSurface() override;
void onSwapBuffers() override;
sk_sp<const GrGLInterface> onInitializeContext() override;
void onDestroyContext() override;
private:
SDL_Window* fWindow;
SDL_GLContext fGLContext;
sk_sp<SkSurface> fBackbufferSurface;
typedef GLWindowContext INHERITED;
};
RasterWindowContext_ios::RasterWindowContext_ios(const IOSWindowInfo& info,
const DisplayParams& params)
: INHERITED(params)
, fWindow(info.fWindow)
, fGLContext(nullptr) {
// any config code here (particularly for msaa)?
this->initializeContext();
}
RasterWindowContext_ios::~RasterWindowContext_ios() {
this->destroyContext();
}
sk_sp<const GrGLInterface> RasterWindowContext_ios::onInitializeContext() {
SkASSERT(fWindow);
SkASSERT(fGLContext);
if (0 == SDL_GL_MakeCurrent(fWindow, fGLContext)) {
glClearStencil(0);
glClearColor(0, 0, 0, 0);
glStencilMask(0xffffffff);
glClear(GL_STENCIL_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
SDL_GL_GetAttribute(SDL_GL_STENCIL_SIZE, &fStencilBits);
SDL_GL_GetAttribute(SDL_GL_MULTISAMPLESAMPLES, &fSampleCount);
fSampleCount = SkTMax(fSampleCount, 1);
SDL_GL_GetDrawableSize(fWindow, &fWidth, &fHeight);
glViewport(0, 0, fWidth, fHeight);
} else {
SkDebugf("MakeCurrent failed: %s\n", SDL_GetError());
}
// make the offscreen image
SkImageInfo info = SkImageInfo::Make(fWidth, fHeight, fDisplayParams.fColorType,
kPremul_SkAlphaType, fDisplayParams.fColorSpace);
fBackbufferSurface = SkSurface::MakeRaster(info);
return GrGLMakeNativeInterface();
}
void RasterWindowContext_ios::onDestroyContext() {
fBackbufferSurface.reset(nullptr);
}
sk_sp<SkSurface> RasterWindowContext_ios::getBackbufferSurface() { return fBackbufferSurface; }
void RasterWindowContext_ios::onSwapBuffers() {
if (fWindow && fGLContext) {
// We made/have an off-screen surface. Get the contents as an SkImage:
sk_sp<SkImage> snapshot = fBackbufferSurface->makeImageSnapshot();
sk_sp<SkSurface> gpuSurface = INHERITED::getBackbufferSurface();
SkCanvas* gpuCanvas = gpuSurface->getCanvas();
gpuCanvas->drawImage(snapshot, 0, 0);
gpuCanvas->flush();
SDL_GL_SwapWindow(fWindow);
}
}
} // anonymous namespace
namespace sk_app {
namespace window_context_factory {
WindowContext* NewRasterForIOS(const IOSWindowInfo& info, const DisplayParams& params) {
WindowContext* ctx = new RasterWindowContext_ios(info, params);
if (!ctx->isValid()) {
delete ctx;
return nullptr;
}
return ctx;
}
} // namespace window_context_factory
} // namespace sk_app