addarc.cpp File Reference

#include "gm/gm.h"
#include "include/core/SkCanvas.h"
#include "include/core/SkColor.h"
#include "include/core/SkPaint.h"
#include "include/core/SkPathBuilder.h"
#include "include/core/SkPathMeasure.h"
#include "include/core/SkPoint.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/SkFloatingPoint.h"
#include "src/base/SkRandom.h"
#include "tools/ToolUtils.h"
#include "tools/timer/TimeUtils.h"

Go to the source code of this file.

Classes
class	AddArcGM
class	StrokeCircleGM
class	FillCircleGM

Macros
#define	R   400

Functions
	DEF_SIMPLE_GM (addarc_meas, canvas, 2 *R+40, 2 *R+40)
static void	html_canvas_arc (SkPathBuilder *path, SkScalar x, SkScalar y, SkScalar r, SkScalar start, SkScalar end, bool ccw, bool callArcTo)
	DEF_SIMPLE_GM (manyarcs, canvas, 620, 330)
	DEF_SIMPLE_GM (tinyanglearcs, canvas, 620, 330)

Macro Definition Documentation

R

#define R   400

Definition at line 78 of file addarc.cpp.

Function Documentation

DEF_SIMPLE_GM() [1/3]

DEF_SIMPLE_GM	(	addarc_meas	,
		canvas	,
		2 *R+	40,
		2 *R+	40
	)

Definition at line 80 of file addarc.cpp.

                                                       {
        canvas->translate(R + 20, R + 20);
 
        SkPaint paint;
        paint.setAntiAlias(true);
        paint.setStroke(true);
 
        SkPaint measPaint;
        measPaint.setAntiAlias(true);
        measPaint.setColor(SK_ColorRED);
 
        const SkRect oval = SkRect::MakeLTRB(-R, -R, R, R);
        canvas->drawOval(oval, paint);
 
        for (SkScalar deg = 0; deg < 360; deg += 10) {
            const SkScalar rad = SkDegreesToRadians(deg);
            SkScalar rx = SkScalarCos(rad) * R;
            SkScalar ry = SkScalarSin(rad) * R;
 
            canvas->drawLine(0, 0, rx, ry, paint);
 
            SkPathMeasure meas(SkPathBuilder().addArc(oval, 0, deg).detach(), false);
            SkScalar arcLen = rad * R;
            SkPoint pos;
            if (meas.getPosTan(arcLen, &pos, nullptr)) {
                canvas->drawLine({0, 0}, pos, measPaint);
            }
        }
}

DEF_SIMPLE_GM() [2/3]

DEF_SIMPLE_GM	(	manyarcs	,
		canvas	,
		620	,
		330
	)

Definition at line 227 of file addarc.cpp.

                                          {
        SkPaint paint;
        paint.setAntiAlias(true);
        paint.setStroke(true);
 
        canvas->translate(10, 10);
 
        // 20 angles.
        SkScalar sweepAngles[] = {
                           -123.7f, -2.3f, -2, -1, -0.3f, -0.000001f, 0, 0.000001f, 0.3f, 0.7f,
                           1, 1.3f, 1.5f, 1.7f, 1.99999f, 2, 2.00001f, 2.3f, 4.3f, 3934723942837.3f
        };
        for (size_t i = 0; i < std::size(sweepAngles); ++i) {
            sweepAngles[i] *= 180;
        }
 
        SkScalar startAngles[] = { -1, -0.5f, 0, 0.5f };
        for (size_t i = 0; i < std::size(startAngles); ++i) {
            startAngles[i] *= 180;
        }
 
        bool anticlockwise = false;
        SkScalar sign = 1;
        for (size_t i = 0; i < std::size(startAngles) * 2; ++i) {
            if (i == std::size(startAngles)) {
                anticlockwise = true;
                sign = -1;
            }
            SkScalar startAngle = startAngles[i % std::size(startAngles)] * sign;
            canvas->save();
            for (size_t j = 0; j < std::size(sweepAngles); ++j) {
                SkPathBuilder path;
                path.moveTo(0, 2);
                html_canvas_arc(&path, 18, 15, 10, startAngle, startAngle + (sweepAngles[j] * sign),
                                anticlockwise, true);
                path.lineTo(0, 28);
                canvas->drawPath(path.detach().setIsVolatile(true), paint);
                canvas->translate(30, 0);
            }
            canvas->restore();
            canvas->translate(0, 40);
        }
}

DEF_SIMPLE_GM() [3/3]

DEF_SIMPLE_GM	(	tinyanglearcs	,
		canvas	,
		620	,
		330
	)

Definition at line 272 of file addarc.cpp.

                                               {
        SkPaint paint;
        paint.setAntiAlias(true);
        paint.setStroke(true);
 
        canvas->translate(50, 50);
 
        SkScalar outerRadius = 100000.0f;
        SkScalar innerRadius = outerRadius - 20.0f;
        SkScalar centerX = 50;
        SkScalar centerY = outerRadius;
        SkScalar startAngles[] = { 1.5f * SK_ScalarPI , 1.501f * SK_ScalarPI  };
        SkScalar sweepAngle = 10.0f / outerRadius;
 
        for (size_t i = 0; i < std::size(startAngles); ++i) {
            SkPathBuilder path;
            SkScalar endAngle = startAngles[i] + sweepAngle;
            path.moveTo(centerX + innerRadius * std::cos(startAngles[i]),
                        centerY + innerRadius * std::sin(startAngles[i]));
            path.lineTo(centerX + outerRadius * std::cos(startAngles[i]),
                        centerY + outerRadius * std::sin(startAngles[i]));
            // A combination of tiny sweepAngle + large radius, we should draw a line.
            html_canvas_arc(&path, centerX, outerRadius, outerRadius,
                            startAngles[i] * 180 / SK_ScalarPI, endAngle * 180 / SK_ScalarPI,
                            true, true);
            path.lineTo(centerX + innerRadius * std::cos(endAngle),
                        centerY + innerRadius * std::sin(endAngle));
            html_canvas_arc(&path, centerX, outerRadius, innerRadius,
                            endAngle * 180 / SK_ScalarPI, startAngles[i] * 180 / SK_ScalarPI,
                            true, false);
            canvas->drawPath(path.detach(), paint);
            canvas->translate(20, 0);
        }
}

html_canvas_arc()

static void html_canvas_arc ( SkPathBuilder *  path, SkScalar  x, SkScalar  y, SkScalar  r, SkScalar  start, SkScalar  end, bool  ccw, bool  callArcTo  )

static

Definition at line 216 of file addarc.cpp.

                                                                    {
    SkRect bounds = { x - r, y - r, x + r, y + r };
    SkScalar sweep = ccw ? end - start : start - end;
    if (callArcTo)
        path->arcTo(bounds, start, sweep, false);
    else
        path->addArc(bounds, start, sweep);
}