virtual void onDraw(SkCanvas* canvas) {
SkRect r = SkRect::MakeWH(FILTER_WIDTH, FILTER_HEIGHT);
SkPaint paint;
paint.setColor(SK_ColorRED);
canvas->save();
for (float brightness = -1.0f; brightness <= 1.0f; brightness += 0.2f) {
SkAutoTUnref<SkImageFilter> dim(make_brightness(-brightness));
SkAutoTUnref<SkImageFilter> bright(make_brightness(brightness, dim));
paint.setImageFilter(bright);
drawClippedRect(canvas, r, paint);
canvas->translate(FILTER_WIDTH + MARGIN, 0);
}
canvas->restore();
canvas->translate(0, FILTER_HEIGHT + MARGIN);
{
SkAutoTUnref<SkImageFilter> brightness(make_brightness(0.9f));
SkAutoTUnref<SkImageFilter> grayscale(make_grayscale(brightness));
paint.setImageFilter(grayscale);
drawClippedRect(canvas, r, paint);
canvas->translate(FILTER_WIDTH + MARGIN, 0);
}
{
SkAutoTUnref<SkImageFilter> grayscale(make_grayscale());
SkAutoTUnref<SkImageFilter> brightness(make_brightness(0.9f, grayscale));
paint.setImageFilter(brightness);
drawClippedRect(canvas, r, paint);
canvas->translate(FILTER_WIDTH + MARGIN, 0);
}
{
SkAutoTUnref<SkImageFilter> blue(make_mode_blue());
SkAutoTUnref<SkImageFilter> brightness(make_brightness(1.0f, blue));
paint.setImageFilter(brightness);
drawClippedRect(canvas, r, paint);
canvas->translate(FILTER_WIDTH + MARGIN, 0);
}
{
SkAutoTUnref<SkImageFilter> brightness(make_brightness(1.0f));
SkAutoTUnref<SkImageFilter> blue(make_mode_blue(brightness));
paint.setImageFilter(blue);
drawClippedRect(canvas, r, paint);
canvas->translate(FILTER_WIDTH + MARGIN, 0);
}
{
SkAutoTUnref<SkImageFilter> blur(make_blur(3.0f));
SkAutoTUnref<SkImageFilter> brightness(make_brightness(0.5f, blur));
paint.setImageFilter(brightness);
drawClippedRect(canvas, r, paint, 3);
canvas->translate(FILTER_WIDTH + MARGIN, 0);
}
{
SkAutoTUnref<SkImageFilter> blue(make_mode_blue());
paint.setImageFilter(blue.get());
drawClippedRect(canvas, r, paint, 5);
canvas->translate(FILTER_WIDTH + MARGIN, 0);
}
}
void onDraw(SkCanvas* canvas) override {
canvas->drawColor(sk_tool_utils::color_to_565(SK_ColorGRAY));
SkPaint paint;
paint.setTypeface(emojiFont.typeface);
const char* text = emojiFont.text;
// draw text at different point sizes
const int textSize[] = { 10, 30, 50, };
const int textYOffset[] = { 10, 40, 100, };
SkASSERT(sizeof(textSize) == sizeof(textYOffset));
size_t y_offset = 0;
for (size_t y = 0; y < sizeof(textSize) / sizeof(int); y++) {
paint.setTextSize(SkIntToScalar(textSize[y]));
canvas->drawText(text, strlen(text), 10, SkIntToScalar(textYOffset[y]), paint);
y_offset += textYOffset[y];
}
// draw with shaders and image filters
for (int makeLinear = 0; makeLinear < 2; makeLinear++) {
for (int makeBlur = 0; makeBlur < 2; makeBlur++) {
for (int makeGray = 0; makeGray < 2; makeGray++) {
SkPaint shaderPaint;
shaderPaint.setTypeface(paint.getTypeface());
if (SkToBool(makeLinear)) {
shaderPaint.setShader(MakeLinear())->unref();
}
if (SkToBool(makeBlur) && SkToBool(makeGray)) {
SkAutoTUnref<SkImageFilter> grayScale(make_grayscale(nullptr));
SkAutoTUnref<SkImageFilter> blur(make_blur(3.0f, grayScale));
shaderPaint.setImageFilter(blur);
} else if (SkToBool(makeBlur)) {
SkAutoTUnref<SkImageFilter> blur(make_blur(3.0f, nullptr));
shaderPaint.setImageFilter(blur);
} else if (SkToBool(makeGray)) {
SkAutoTUnref<SkImageFilter> grayScale(make_grayscale(nullptr));
shaderPaint.setImageFilter(grayScale);
}
shaderPaint.setTextSize(30);
canvas->drawText(text, strlen(text), 380, SkIntToScalar(y_offset),
shaderPaint);
y_offset += 32;
}
}
}
// setup work needed to draw text with different clips
canvas->translate(10, 160);
paint.setTextSize(40);
// compute the bounds of the text
SkRect bounds;
paint.measureText(text, strlen(text), &bounds);
const SkScalar boundsHalfWidth = bounds.width() * SK_ScalarHalf;
const SkScalar boundsHalfHeight = bounds.height() * SK_ScalarHalf;
const SkScalar boundsQuarterWidth = boundsHalfWidth * SK_ScalarHalf;
const SkScalar boundsQuarterHeight = boundsHalfHeight * SK_ScalarHalf;
SkRect upperLeftClip = SkRect::MakeXYWH(bounds.left(), bounds.top(),
boundsHalfWidth, boundsHalfHeight);
SkRect lowerRightClip = SkRect::MakeXYWH(bounds.centerX(), bounds.centerY(),
boundsHalfWidth, boundsHalfHeight);
SkRect interiorClip = bounds;
interiorClip.inset(boundsQuarterWidth, boundsQuarterHeight);
const SkRect clipRects[] = { bounds, upperLeftClip, lowerRightClip, interiorClip };
SkPaint clipHairline;
clipHairline.setColor(SK_ColorWHITE);
clipHairline.setStyle(SkPaint::kStroke_Style);
for (size_t x = 0; x < sizeof(clipRects) / sizeof(SkRect); ++x) {
canvas->save();
canvas->drawRect(clipRects[x], clipHairline);
paint.setAlpha(0x20);
canvas->drawText(text, strlen(text), 0, 0, paint);
canvas->clipRect(clipRects[x]);
paint.setAlpha(0xFF);
canvas->drawText(text, strlen(text), 0, 0, paint);
canvas->restore();
canvas->translate(0, bounds.height() + SkIntToScalar(25));
}
}
