android skia 使用執行個體

#include "SkBitmap.h" #include "SkDevice.h" #include "SkPaint.h"   #include "SkRect.h" #include "SkImageEncoder.h"   int main() {         // Declare a raster bitmap, which has an integer width and height,         // and a format (config), and a pointer to the actual pixels.         // Bitmaps can be drawn into a SkCanvas, but they are also used to           // specify the target of a SkCanvas' drawing operations.         SkBitmap bitmap;         bitmap.setConfig(SkBitmap::kARGB_8888_Config, 200, 200);         bitmap.allocPixels();           // A Canvas encapsulates all of the state about drawing into a         // device (bitmap).  This includes a reference to the device itself,         // and a stack of matrix/clip values. For any given draw call (e.g.         // drawRect), the geometry of the object being drawn is transformed         // by the concatenation of all the matrices in the stack. The         // transformed geometry is clipped by the intersection of all of the           // clips in the stack.         SkCanvas canvas(new SkDevice(bitmap));           // SkPaint class holds the style and color information about how to         // draw geometries, text and bitmaps.         SkPaint paint;           // SkIRect holds four 32 bit integer coordinates for a rectangle.           SkRect r;           paint.setARGB(255, 255, 0, 0);         r.set(25, 25, 145, 145);         canvas.drawRect(r, paint);           paint.setARGB(255, 0, 255, 0);         r.offset(20, 20);         canvas.drawRect(r, paint);           paint.setARGB(255, 0, 0, 255);         r.offset(20, 20);         canvas.drawRect(r, paint);           // SkImageEncoder is the base class for encoding compressed images         // from a specific SkBitmap.         SkImageEncoder::EncodeFile("snapshot.png", bitmap,                SkImageEncoder::kPNG_Type,                100);         return 0; } 編譯方式： g++ \         -I./include \         -I./include/core \         -I./include/images \                                                                       -Wall -o test-skia test-skia.c \         out/src/images/SkImageDecoder_libpng.o out/libskia.a \         -lpng -lpthread -g 筆者做了簡要的批註，大概可知曉 Sk 開頭的這些 API 的功用，而上述的範常式序一開始就要求 Skia 配置畫布 (SkCanvas)，接著透過一份 SkRect 對象 r，給定 ARGB 的描述，使其有著不同的顏色，再來就是調整向量對象的位移並繪製。正如前文提及，Skia 僅是繪圖引擎，並未如 Cairo 一般廣泛對應到 PDF, X11, GDI 等等底層繪圖裝置，所以為了方便觀察繪圖結果，我們透過 Skia 內建的 image codec 來輸出 PNG 圖檔，所以執行前述編譯後的執行檔 "test-skia"，應該會得到以檔：(本無外框與底色，但為了清楚於文章呈現，額外用繪圖軟體追加)   迭合的三個不同色的矩形對象，就是透過以下 API 呼叫達成：         paint.setARGB(255, 0, 255, 0);         r.offset(20, 20);         canvas.drawRect(r, paint); 由於 Skia 與 Cairo 的同構型相當高，也可參照 [Cairo :: documentation] 建立所需的背景知識。 轉載， 原地址：http://blog.sina.com.cn/s/blog_4a0a39c30100cog4.html 另外一個例子： #include "SkBitmap.h"#include "SkDevice.h"#include "SkPaint.h"#include "SkRect.h"#include <cairo.h>int main(){ SkBitmap bitmap; bitmap.setConfig(SkBitmap::kARGB_8888_Config, 100, 100); bitmap.allocPixels(); SkDevice device(bitmap); SkCanvas canvas(&device); SkPaint paint; SkRect r; paint.setARGB(255, 255, 255, 255); r.set(10, 10, 20, 20); canvas.drawRect(r, paint); paint.setARGB(255, 255, 0, 0); r.offset(5, 5); canvas.drawRect(r, paint); paint.setARGB(255, 0, 0, 255); r.offset(5, 5); canvas.drawRect(r, paint); { SkAutoLockPixels image_lock(bitmap); cairo_surface_t* surface = cairo_image_surface_create_for_data( (unsigned char*)bitmap.getPixels(), CAIRO_FORMAT_ARGB32, bitmap.width(), bitmap.height(), bitmap.rowBytes()); cairo_surface_write_to_png(surface, "snapshot.png"); cairo_surface_destroy(surface); } return 0;}原地址：http://www.linuxgraphics.cn/android/skia.html