gm_HAL_xfermodes.cpp

#include "gm.h"
#include "SkGradientShader.h"
DEF_SIMPLE_GM(HAL_xfermodes, canvas, 576, 640) {
    SkXfermode::Mode modes[] = {
        SkXfermode::kClear_Mode,
        SkXfermode::kSrc_Mode,
        SkXfermode::kDst_Mode,
        SkXfermode::kSrcOver_Mode,
        SkXfermode::kDstOver_Mode,
        SkXfermode::kSrcIn_Mode,
        SkXfermode::kDstIn_Mode,
        SkXfermode::kSrcOut_Mode,
        SkXfermode::kDstOut_Mode,
        SkXfermode::kSrcATop_Mode,
        SkXfermode::kDstATop_Mode,
        SkXfermode::kXor_Mode,
        SkXfermode::kPlus_Mode,
        SkXfermode::kModulate_Mode,
        SkXfermode::kScreen_Mode,
        SkXfermode::kOverlay_Mode,
        SkXfermode::kDarken_Mode,
        SkXfermode::kLighten_Mode,
        SkXfermode::kColorDodge_Mode,
        SkXfermode::kColorBurn_Mode,
        SkXfermode::kHardLight_Mode,
        SkXfermode::kSoftLight_Mode,
        SkXfermode::kDifference_Mode,
        SkXfermode::kExclusion_Mode,
        SkXfermode::kMultiply_Mode,
        SkXfermode::kHue_Mode,
        SkXfermode::kSaturation_Mode,
        SkXfermode::kColor_Mode,
        SkXfermode::kLuminosity_Mode,
    };
    SkRect rect = SkRect::MakeWH(64.0f, 64.0f);
    SkPaint text, stroke, src, dst;
    stroke.setStyle(SkPaint::kStroke_Style);
    text.setTextSize(24.0f);
    text.setAntiAlias(true);
    SkPoint srcPoints[2] = {
        SkPoint::Make(0.0f, 0.0f),
        SkPoint::Make(64.0f, 0.0f)
    };
    SkColor srcColors[2] = {
        SK_ColorMAGENTA & 0x00FFFFFF,
        SK_ColorMAGENTA};
    SkAutoTUnref<SkShader> srcShader(
            SkGradientShader::CreateLinear(
                    srcPoints, srcColors, nullptr, 2,
                    SkShader::kClamp_TileMode, 0, nullptr));
    src.setShader(srcShader);

    SkPoint dstPoints[2] = {
        SkPoint::Make(0.0f, 0.0f),
        SkPoint::Make(0.0f, 64.0f)
    };
    SkColor dstColors[2] = {
        SK_ColorCYAN & 0x00FFFFFF,
        SK_ColorCYAN};
    SkAutoTUnref<SkShader> dstShader(
            SkGradientShader::CreateLinear(
                    dstPoints, dstColors, nullptr, 2,
                    SkShader::kClamp_TileMode, 0, nullptr));
    dst.setShader(dstShader);
    canvas->clear(SK_ColorWHITE);
    size_t N = sizeof(modes) / sizeof(modes[0]);
    size_t K = (N - 1) / 3 + 1;
    SkASSERT(K * 64 == 640);  // tall enough
    for (size_t i = 0; i < N; ++i) {
        SkAutoCanvasRestore autoCanvasRestore(canvas, true);
        canvas->translate(192.0f * (i / K), 64.0f * (i % K));
        const char* desc = SkXfermode::ModeName(modes[i]);
        canvas->drawText(desc, strlen(desc), 68.0f, 30.0f, text);
        canvas->clipRect(SkRect::MakeWH(64.0f, 64.0f));
        canvas->drawColor(SK_ColorLTGRAY);
        (void)canvas->saveLayer(nullptr, nullptr);
        canvas->clear(SK_ColorTRANSPARENT);
        canvas->drawPaint(dst);
        src.setXfermodeMode(modes[i]);
        canvas->drawPaint(src);
        canvas->drawRect(rect, stroke);
     }
}