skia2/tools/sk_app/ios/RasterWindowContext_ios.cpp
Brian Salomon 48825b11ad Redefine the meaning of sample counts in GPU backend.
Old: 0  -> nonMSAA
     1+ -> MSAA

New:
     0  -> error/unsupported
     1  -> nonMSAA
     2+ -> MSAA

We still allow 0 to mean nonMSAA in three sets of public APIs for backwards compatibility:

1) SkSurface factories
2) GrBackendRenderTarget constructors
3) GrCaps::getSampleCnt()'s requestedCount parameter

However, we immediately clamp to 1 and treat 0 as invalid/non-renderable internally.

This also changes the behavior when using a large sample count. We now fail in that case rather than using the largest sample available sample count. GrCaps::getSampleCount() will return 0 in this case.


Bug: skia:
Change-Id: Ida22c6b22c1365e563c9046b611e88bf5eb3ff33
Reviewed-on: https://skia-review.googlesource.com/101560
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
2018-02-01 18:16:58 +00:00

138 lines
4.0 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);
fGLContext = SDL_GL_CreateContext(fWindow);
if (!fGLContext) {
SkDebugf("%s\n", SDL_GetError());
return nullptr;
}
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() {
if (!fWindow || !fGLContext) {
return;
}
fBackbufferSurface.reset(nullptr);
SDL_GL_DeleteContext(fGLContext);
fGLContext = 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