SkPDFShader::State::State(const SkShader& shader, const SkMatrix& canvasTransform,
const SkIRect& bbox, SkScalar rasterScale)
: fCanvasTransform(canvasTransform),
fBBox(bbox),
fPixelGeneration(0) {
fInfo.fColorCount = 0;
fInfo.fColors = NULL;
fInfo.fColorOffsets = NULL;
fShaderTransform = shader.getLocalMatrix();
fImageTileModes[0] = fImageTileModes[1] = SkShader::kClamp_TileMode;
fType = shader.asAGradient(&fInfo);
if (fType == SkShader::kNone_GradientType) {
SkMatrix matrix;
if (shader.isABitmap(&fImage, &matrix, fImageTileModes)) {
SkASSERT(matrix.isIdentity());
} else {
// Generic fallback for unsupported shaders:
// * allocate a bbox-sized bitmap
// * shade the whole area
// * use the result as a bitmap shader
// bbox is in device space. While that's exactly what we want for sizing our bitmap,
// we need to map it into shader space for adjustments (to match
// SkPDFImageShader::Create's behavior).
SkRect shaderRect = SkRect::Make(bbox);
if (!inverse_transform_bbox(canvasTransform, &shaderRect)) {
fImage.reset();
return;
}
// Clamp the bitmap size to about 1M pixels
static const SkScalar kMaxBitmapArea = 1024 * 1024;
SkScalar bitmapArea = rasterScale * bbox.width() * rasterScale * bbox.height();
if (bitmapArea > kMaxBitmapArea) {
rasterScale *= SkScalarSqrt(kMaxBitmapArea / bitmapArea);
}
SkISize size = SkISize::Make(SkScalarRoundToInt(rasterScale * bbox.width()),
SkScalarRoundToInt(rasterScale * bbox.height()));
SkSize scale = SkSize::Make(SkIntToScalar(size.width()) / shaderRect.width(),
SkIntToScalar(size.height()) / shaderRect.height());
fImage.allocN32Pixels(size.width(), size.height());
fImage.eraseColor(SK_ColorTRANSPARENT);
SkPaint p;
p.setShader(const_cast<SkShader*>(&shader));
SkCanvas canvas(fImage);
canvas.scale(scale.width(), scale.height());
canvas.translate(-shaderRect.x(), -shaderRect.y());
canvas.drawPaint(p);
fShaderTransform.setTranslate(shaderRect.x(), shaderRect.y());
fShaderTransform.preScale(1 / scale.width(), 1 / scale.height());
}
fPixelGeneration = fImage.getGenerationID();
} else {
AllocateGradientInfoStorage();
shader.asAGradient(&fInfo);
}
}
