tallstretchedbitmaps.cpp File Reference

#include "gm/gm.h"
#include "include/core/SkBitmap.h"
#include "include/core/SkCanvas.h"
#include "include/core/SkImage.h"
#include "include/core/SkPaint.h"
#include "include/core/SkRect.h"
#include "include/core/SkScalar.h"
#include "include/core/SkSize.h"
#include "include/core/SkString.h"
#include "include/core/SkTypes.h"
#include "include/private/base/SkTo.h"
#include "src/base/SkRandom.h"
#include "tools/GpuToolUtils.h"
#include "tools/ToolUtils.h"

Go to the source code of this file.

Classes
class	TallStretchedBitmapsGM

Functions
int	make_bm (SkBitmap *bm, int height)

Function Documentation

make_bm()

int make_bm	(	SkBitmap *	bm,
		int	height
	)

Definition at line 23 of file tallstretchedbitmaps.cpp.

                                      {
    constexpr int kRadius = 22;
    constexpr int kMargin = 8;
    constexpr SkScalar kStartAngle = 0;
    constexpr SkScalar kDAngle = 25;
    constexpr SkScalar kSweep = 320;
    constexpr SkScalar kThickness = 8;
 
    int count = (height / (2 * kRadius + kMargin));
    height = count * (2 * kRadius + kMargin);
 
    bm->allocN32Pixels(2 * (kRadius + kMargin), height);
    SkRandom random;
 
    SkCanvas wholeCanvas(*bm);
    wholeCanvas.clear(0x00000000);
 
    SkScalar angle = kStartAngle;
    for (int i = 0; i < count; ++i) {
        SkPaint paint;
        // The sw rasterizer disables AA for large canvii. So we make a small canvas for each draw.
        SkBitmap smallBM;
        SkIRect subRect = SkIRect::MakeXYWH(0, i * (kMargin + 2 * kRadius),
                                            2 * kRadius + kMargin, 2 * kRadius + kMargin);
        bm->extractSubset(&smallBM, subRect);
        SkCanvas canvas(smallBM);
        canvas.translate(kMargin + kRadius, kMargin + kRadius);
 
        paint.setAntiAlias(true);
        paint.setColor(random.nextU() | 0xFF000000);
        paint.setStyle(SkPaint::kStroke_Style);
        paint.setStrokeWidth(kThickness);
        paint.setStrokeCap(SkPaint::kRound_Cap);
        SkScalar radius = kRadius - kThickness / 2;
        SkRect bounds = SkRect::MakeLTRB(-radius, -radius, radius, radius);
 
        canvas.drawArc(bounds, angle, kSweep, false, paint);
        angle += kDAngle;
    }
    bm->setImmutable();
    return count;
}