Tweak SkPictureShader's tile semantics.

Currently, the tile offset is added when drawing the picture. This might
have made a tiny bit of sense when the picture was always positioned at
origin, but with a picture cull rect offset things looks really strange.

For example, to specify a tile == the picture cull rect we have to pass
in [-cullrect.x, -cullrect.y, cullrect.width, cullrect.height]. Yikes.

(there's also a bug when not passing a tile, as we use a default tile
== cullrect but don't compensate for the above oddity)

This changes the semantics of the tile offset: it is now subtracted when
drawing the picture tile. As a consequence, one can pass in a tile equal
to the cull rect and get the expected behavior (same when not passing
a tile).

This will require a minor Blink change with the roll, as one client
works around the current behavior:
https://codereview.chromium.org/789503003

R=reed@google.com,robertphillips@google.com
BUG=440046

Review URL: https://codereview.chromium.org/733203005
This commit is contained in:
fmalita 2014-12-08 11:13:27 -08:00 committed by Commit bot
parent cf56009d90
commit a2bd24fd15
2 changed files with 51 additions and 35 deletions

View File

@ -21,68 +21,43 @@ static const struct {
SkScalar offsetX, offsetY;
} tiles[] = {
{ 0, 0, 1, 1, 0, 0 },
{ 0.5f, 0.5f, 1, 1, 0, 0 },
{ -0.5f, -0.5f, 1, 1, 0, 0 },
{ 0.5f, 0.5f, 1, 1, 0, 0 },
{ 0, 0, 1.5f, 1.5f, 0, 0 },
{ 0.5f, 0.5f, 1.5f, 1.5f, 0, 0 },
{ -0.5f, -0.5f, 1.5f, 1.5f, 0, 0 },
{ 0.5f, 0.5f, 1.5f, 1.5f, 0, 0 },
{ 0, 0, 0.5f, 0.5f, 0, 0 },
{ -0.25f, -0.25f, 0.5f, 0.5f, 0, 0 },
{ 0.25f, 0.25f, 0.5f, 0.5f, 0, 0 },
{ -0.25f, -0.25f, 0.5f, 0.5f, 0, 0 },
{ 0, 0, 1, 1, 0.5f, 0.5f },
{ 0.5f, 0.5f, 1, 1, 0.5f, 0.5f },
{ -0.5f, -0.5f, 1, 1, 0.5f, 0.5f },
{ 0.5f, 0.5f, 1, 1, 0.5f, 0.5f },
{ 0, 0, 1.5f, 1.5f, 0.5f, 0.5f },
{ 0.5f, 0.5f, 1.5f, 1.5f, 0.5f, 0.5f },
{ -0.5f, -0.5f, 1.5f, 1.5f, 0.5f, 0.5f },
{ 0.5f, 0.5f, 1.5f, 1.5f, 0.5f, 0.5f },
{ 0, 0, 1.5f, 1, 0, 0 },
{ 0.5f, 0.5f, 1.5f, 1, 0, 0 },
{ -0.5f, -0.5f, 1.5f, 1, 0, 0 },
{ 0.5f, 0.5f, 1.5f, 1, 0, 0 },
{ 0, 0, 0.5f, 1, 0, 0 },
{ -0.25f, -0.25f, 0.5f, 1, 0, 0 },
{ 0.25f, 0.25f, 0.5f, 1, 0, 0 },
{ -0.25f, -0.25f, 0.5f, 1, 0, 0 },
{ 0, 0, 1, 1.5f, 0, 0 },
{ 0.5f, 0.5f, 1, 1.5f, 0, 0 },
{ -0.5f, -0.5f, 1, 1.5f, 0, 0 },
{ 0.5f, 0.5f, 1, 1.5f, 0, 0 },
{ 0, 0, 1, 0.5f, 0, 0 },
{ -0.25f, -0.25f, 1, 0.5f, 0, 0 },
{ 0.25f, 0.25f, 1, 0.5f, 0, 0 },
{ -0.25f, -0.25f, 1, 0.5f, 0, 0 },
};
class PictureShaderTileGM : public skiagm::GM {
public:
PictureShaderTileGM() {
SkPictureRecorder recorder;
SkCanvas* pictureCanvas = recorder.beginRecording(kPictureSize, kPictureSize, NULL, 0);
drawScene(pictureCanvas, kPictureSize);
SkAutoTUnref<SkPicture> picture(recorder.endRecording());
for (unsigned i = 0; i < SK_ARRAY_COUNT(tiles); ++i) {
SkRect tile = SkRect::MakeXYWH(tiles[i].x * kPictureSize,
tiles[i].y * kPictureSize,
tiles[i].w * kPictureSize,
tiles[i].h * kPictureSize);
SkMatrix localMatrix;
localMatrix.setTranslate(tiles[i].offsetX * kPictureSize,
tiles[i].offsetY * kPictureSize);
localMatrix.postScale(kFillSize / (2 * kPictureSize),
kFillSize / (2 * kPictureSize));
fShaders[i].reset(SkShader::CreatePictureShader(picture,
SkShader::kRepeat_TileMode,
SkShader::kRepeat_TileMode,
&localMatrix,
&tile));
}
}
protected:
virtual uint32_t onGetFlags() const SK_OVERRIDE {
return kSkipTiled_Flag;
@ -96,6 +71,47 @@ protected:
return SkISize::Make(800, 600);
}
virtual void onOnceBeforeDraw() SK_OVERRIDE {
SkPictureRecorder recorder;
SkCanvas* pictureCanvas = recorder.beginRecording(kPictureSize, kPictureSize);
drawScene(pictureCanvas, kPictureSize);
SkAutoTUnref<SkPicture> picture(recorder.endRecording());
SkPoint offset = SkPoint::Make(100, 100);
pictureCanvas = recorder.beginRecording(SkRect::MakeXYWH(offset.x(), offset.y(),
kPictureSize, kPictureSize));
pictureCanvas->translate(offset.x(), offset.y());
drawScene(pictureCanvas, kPictureSize);
SkAutoTUnref<SkPicture> offsetPicture(recorder.endRecording());
for (unsigned i = 0; i < SK_ARRAY_COUNT(tiles); ++i) {
SkRect tile = SkRect::MakeXYWH(tiles[i].x * kPictureSize,
tiles[i].y * kPictureSize,
tiles[i].w * kPictureSize,
tiles[i].h * kPictureSize);
SkMatrix localMatrix;
localMatrix.setTranslate(tiles[i].offsetX * kPictureSize,
tiles[i].offsetY * kPictureSize);
localMatrix.postScale(kFillSize / (2 * kPictureSize),
kFillSize / (2 * kPictureSize));
SkPicture* picturePtr = picture.get();
SkRect* tilePtr = &tile;
if (tile == SkRect::MakeWH(kPictureSize, kPictureSize)) {
// When the tile == picture bounds, exercise the picture + offset path.
picturePtr = offsetPicture.get();
tilePtr = NULL;
}
fShaders[i].reset(SkShader::CreatePictureShader(picturePtr,
SkShader::kRepeat_TileMode,
SkShader::kRepeat_TileMode,
&localMatrix,
tilePtr));
}
}
virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
canvas->clear(SK_ColorBLACK);

View File

@ -185,7 +185,7 @@ SkShader* SkPictureShader::refBitmapShader(const SkMatrix& matrix, const SkMatri
SkCanvas canvas(bm);
canvas.scale(tileScale.width(), tileScale.height());
canvas.translate(fTile.x(), fTile.y());
canvas.translate(-fTile.x(), -fTile.y());
canvas.drawPicture(fPicture);
SkMatrix shaderMatrix = this->getLocalMatrix();