lumafilter.cpp File Reference

#include "gm/gm.h"
#include "include/core/SkBlendMode.h"
#include "include/core/SkCanvas.h"
#include "include/core/SkColor.h"
#include "include/core/SkColorFilter.h"
#include "include/core/SkColorSpace.h"
#include "include/core/SkFont.h"
#include "include/core/SkFontTypes.h"
#include "include/core/SkPaint.h"
#include "include/core/SkPoint.h"
#include "include/core/SkRect.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkScalar.h"
#include "include/core/SkShader.h"
#include "include/core/SkSize.h"
#include "include/core/SkString.h"
#include "include/core/SkTileMode.h"
#include "include/core/SkTypeface.h"
#include "include/core/SkTypes.h"
#include "include/effects/SkGradientShader.h"
#include "include/effects/SkLumaColorFilter.h"
#include "include/effects/SkRuntimeEffect.h"
#include "src/core/SkColorFilterPriv.h"
#include "tools/DecodeUtils.h"
#include "tools/Resources.h"
#include "tools/ToolUtils.h"
#include "tools/fonts/FontToolUtils.h"
#include <string.h>

Go to the source code of this file.

Classes
class	LumaFilterGM

Functions
static void	draw_label (SkCanvas *canvas, const char *label, const SkPoint &offset)
static void	draw_scene (SkCanvas *canvas, const sk_sp< SkColorFilter > &filter, SkBlendMode mode, const sk_sp< SkShader > &s1, const sk_sp< SkShader > &s2)
	DEF_SIMPLE_GM (AlternateLuma, canvas, 384, 128)

Variables
static SkScalar	kSize = 80
static SkScalar	kInset = 10
static SkColor	kColor1 = SkColorSetARGB(0xff, 0xff, 0xff, 0)
static SkColor	kColor2 = SkColorSetARGB(0xff, 0x82, 0xff, 0)

Function Documentation

DEF_SIMPLE_GM()

DEF_SIMPLE_GM	(	AlternateLuma	,
		canvas	,
		384	,
		128
	)

Definition at line 171 of file lumafilter.cpp.

                                              {
    sk_sp<SkImage> img = ToolUtils::GetResourceAsImage("images/mandrill_128.png");
    if (!img) {
        return;
    }
 
    // Normal luma colorfilter on the left.
    SkPaint paint;
    paint.setColorFilter(SkLumaColorFilter::Make());
    canvas->drawImage(img, 0,0, SkFilterMode::kNearest, &paint);
    canvas->translate(128,0);
 
    // Original image in the middle for reference.
    canvas->drawImage(img, 0,0);
    canvas->translate(128,0);
 
    // Here, RGB holds CIE XYZ. Splatting the G (Y) channel should result in (near) greyscale.
    auto [effect, err] = SkRuntimeEffect::MakeForColorFilter(SkString{
            "half4 main(half4 inColor) { return inColor.ggga; }"});
    SkASSERT(effect && err.isEmpty());
 
    sk_sp<SkColorFilter> filter = effect->makeColorFilter(SkData::MakeEmpty());
    SkASSERT(filter);
 
    SkAlphaType unpremul = kUnpremul_SkAlphaType;
    paint.setColorFilter(SkColorFilterPriv::WithWorkingFormat(std::move(filter),
                                                              &SkNamedTransferFn::kLinear,
                                                              &SkNamedGamut::kXYZ,
                                                              &unpremul));
    canvas->drawImage(img, 0,0, SkFilterMode::kNearest, &paint);
}

draw_label()

static void draw_label ( SkCanvas *  canvas, const char *  label, const SkPoint &  offset  )

static

Definition at line 43 of file lumafilter.cpp.

                                              {
    SkFont font = ToolUtils::DefaultPortableFont();
    font.setEdging(SkFont::Edging::kAlias);
 
    size_t len = strlen(label);
 
    SkScalar width = font.measureText(label, len, SkTextEncoding::kUTF8);
    canvas->drawSimpleText(label, len, SkTextEncoding::kUTF8, offset.x() - width / 2, offset.y(),
                           font, SkPaint());
}

draw_scene()

static void draw_scene ( SkCanvas *  canvas, const sk_sp< SkColorFilter > &  filter, SkBlendMode  mode, const sk_sp< SkShader > &  s1, const sk_sp< SkShader > &  s2  )

static

Definition at line 55 of file lumafilter.cpp.

                                                                             {
    SkPaint paint;
    paint.setAntiAlias(true);
    SkRect r, c, bounds = SkRect::MakeWH(kSize, kSize);
 
    c = bounds;
    c.fRight = bounds.centerX();
    paint.setARGB(0x20, 0, 0, 0xff);
    canvas->drawRect(bounds, paint);
 
    canvas->saveLayer(&bounds, nullptr);
 
    r = bounds;
    r.inset(kInset, 0);
    paint.setShader(s1);
    paint.setColor(s1 ? SK_ColorBLACK : SkColorSetA(kColor1, 0x80));
    canvas->drawOval(r, paint);
    if (!s1) {
        canvas->save();
        canvas->clipRect(c);
        paint.setColor(kColor1);
        canvas->drawOval(r, paint);
        canvas->restore();
    }
 
    SkPaint xferPaint;
    xferPaint.setBlendMode(mode);
    canvas->saveLayer(&bounds, &xferPaint);
 
    r = bounds;
    r.inset(0, kInset);
    paint.setShader(s2);
    paint.setColor(s2 ? SK_ColorBLACK : SkColorSetA(kColor2, 0x80));
    paint.setColorFilter(filter);
    canvas->drawOval(r, paint);
    if (!s2) {
        canvas->save();
        canvas->clipRect(c);
        paint.setColor(kColor2);
        canvas->drawOval(r, paint);
        canvas->restore();
    }
 
    canvas->restore();
    canvas->restore();
}

Variable Documentation

kColor1

SkColor kColor1 = SkColorSetARGB(0xff, 0xff, 0xff, 0)

static

Definition at line 40 of file lumafilter.cpp.

kColor2

SkColor kColor2 = SkColorSetARGB(0xff, 0x82, 0xff, 0)

static

Definition at line 41 of file lumafilter.cpp.

kInset

SkScalar kInset = 10

static

Definition at line 39 of file lumafilter.cpp.

kSize

SkScalar kSize = 80

static

Definition at line 38 of file lumafilter.cpp.