例子

#include "demo.h"
#include "include/core/SkBitmap.h"
#include "include/core/SkImageInfo.h"
#include "include/core/SkFont.h"
#include "include/core/SkImage.h"
#include "utils/file_utils.h"

void drawDemo() {
    SkBitmap bitmap;
    bitmap.setInfo(SkImageInfo::MakeN32(640, 640, kOpaque_SkAlphaType));
    bitmap.allocPixels();
    SkCanvas canvas(bitmap);
    canvas.clear(SK_ColorWHITE);
    SkPaint paint;
    paint.setAntiAlias(true);
    paint.setColor(SK_ColorBLUE);
    canvas.drawLine(SkPoint::Make(0, 0), SkPoint::Make(640, 640), paint);
    paint.setColor(SK_ColorBLACK);
    paint.setStrokeWidth(20);
    canvas.drawPoint(SkPoint::Make(320, 320), paint);
    paint.setStrokeWidth(2);
    paint.setColor(SK_ColorRED);
    paint.setStyle(SkPaint::Style::kStroke_Style);
    canvas.drawCircle(320, 320, 32, paint);
    canvas.drawCircle(SkPoint::Make(320, 320), 64, paint);
    paint.setColor(SK_ColorRED);
    canvas.drawRect(SkRect::MakeXYWH(100, 100, 160, 64), paint);
    canvas.drawRoundRect(SkRect::MakeXYWH(360, 360, 120, 120), SkIntToScalar(10), SkIntToScalar(10), paint);
    paint.setStrokeWidth(1);
    SkFont font;
    font.setSize(SkIntToScalar(23));
    canvas.drawString("SkiaFly", 200, 200, font, paint);
    saveBitmapAsPng("draw_basic_shape.png", bitmap);
}

一些小说明

• SkScalar
看一下定义:

typedef float SkScalar;

其实就是个float.
我们平时使用的时候,可以直接使用float值,也可以使用SkIntToScalar(x)进行转换.

• SkPoint
可以使用静态构造方法构造:

SkPoint::Make(320,320)

• SkRect
也是使用静态构造方法创建:

SkRect::MakeXYWH(100,100,160,64)

其他类型的构造方法其实也差不多,看一下源码和定义也就知道用途了.

源码地址