Index: cmake/example.cpp |
diff --git a/cmake/example.cpp b/cmake/example.cpp |
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+++ b/cmake/example.cpp |
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+/* |
+ * Copyright 2015 Google Inc. |
+ * |
+ * Use of this source code is governed by a BSD-style license that can be |
+ * found in the LICENSE file. |
+ */ |
+ |
+#include "../include/core/SkCanvas.h" |
+#include "../include/core/SkData.h" |
+#include "../include/core/SkSurface.h" |
+#include "../include/effects/SkGradientShader.h" |
+#include "../include/gpu/GrContext.h" |
+ |
+// These headers are just handy for writing this example file. Nothing Skia specific. |
+#include <cstdlib> |
+#include <ctime> |
+#include <fstream> |
+#include <iostream> |
+#include <memory> |
+ |
+#if defined(__APPLE__) |
+ #include <OpenGL/OpenGL.h> |
+ static void setup_gl_context() { |
+ // This is not meant to represent good form. It's just a quick hack to get us going. |
+ CGLPixelFormatAttribute attributes[] = { (CGLPixelFormatAttribute)0 }; |
+ CGLPixelFormatObj format; |
+ GLint npix; |
+ CGLChoosePixelFormat(attributes, &format, &npix); |
+ CGLContextObj context; |
+ CGLCreateContext(format, nullptr, &context); |
+ CGLSetCurrentContext(context); |
+ CGLReleasePixelFormat(format); |
+ } |
+#endif |
+ |
+// Most pointers returned by Skia are derived from SkRefCnt, |
+// meaning we need to call ->unref() on them when done rather than delete them. |
+template <typename T> std::shared_ptr<T> adopt(T* ptr) { |
+ return std::shared_ptr<T>(ptr, [](T* p) { p->unref(); }); |
+} |
+ |
+static std::shared_ptr<SkSurface> create_raster_surface(int w, int h) { |
+ std::cout << "Using raster surface" << std::endl; |
+ return adopt(SkSurface::NewRasterN32Premul(w, h)); |
+} |
+ |
+static std::shared_ptr<SkSurface> create_opengl_surface(int w, int h) { |
+ std::cout << "Using opengl surface" << std::endl; |
+ std::shared_ptr<GrContext> grContext = adopt(GrContext::Create(kOpenGL_GrBackend, 0)); |
+ return adopt(SkSurface::NewRenderTarget(grContext.get(), |
+ SkSurface::kNo_Budgeted, |
+ SkImageInfo::MakeN32Premul(w,h))); |
+} |
+ |
+int main(int, char**) { |
+ setup_gl_context(); |
+ srand(time(nullptr)); |
+ std::shared_ptr<SkSurface> surface = (rand() % 2) ? create_raster_surface(320, 240) |
+ : create_opengl_surface(320, 240); |
+ |
+ // Create a left-to-right green-to-purple gradient shader. |
+ SkPoint pts[] = { {0,0}, {320,240} }; |
+ SkColor colors[] = { 0xFF00FF00, 0xFFFF00FF }; |
+ std::shared_ptr<SkShader> shader = adopt( |
+ SkGradientShader::CreateLinear(pts, colors, nullptr, 2, SkShader::kRepeat_TileMode)); |
+ |
+ // Our text will draw with this paint: size 24, antialiased, with the shader. |
+ SkPaint paint; |
+ paint.setTextSize(24); |
+ paint.setAntiAlias(true); |
+ paint.setShader(shader.get()); |
+ |
+ // Draw to the surface via its SkCanvas. |
+ SkCanvas* canvas = surface->getCanvas(); // We don't manage this pointer's lifetime. |
+ static const char* msg = "Hello world!"; |
+ canvas->clear(SK_ColorWHITE); |
+ canvas->drawText(msg, strlen(msg), 90,120, paint); |
+ |
+ // Grab a snapshot of the surface as an immutable SkImage. |
+ std::shared_ptr<SkImage> image = adopt(surface->newImageSnapshot()); |
+ // Encode that image as a .png into a blob in memory. |
+ std::shared_ptr<SkData> png = adopt(image->encode(SkImageEncoder::kPNG_Type, 100)); |
+ |
+ // This code is no longer Skia-specific. We just dump the .png to disk. Any way works. |
+ static const char* path = "example.png"; |
+ std::ofstream(path, std::ios::out | std::ios::binary) |
+ .write((const char*)png->data(), png->size()); |
+ std::cout << "Wrote " << path << std::endl; |
+ |
+ return 0; |
+} |