GrTexture* GaussianBlur(GrContext* context,
GrTexture* srcTexture,
bool canClobberSrc,
const SkRect& dstBounds,
const SkRect* srcBounds,
float sigmaX,
float sigmaY,
GrTextureProvider::SizeConstraint constraint) {
SkASSERT(context);
SkIRect clearRect;
int scaleFactorX, radiusX;
int scaleFactorY, radiusY;
int maxTextureSize = context->caps()->maxTextureSize();
sigmaX = adjust_sigma(sigmaX, maxTextureSize, &scaleFactorX, &radiusX);
sigmaY = adjust_sigma(sigmaY, maxTextureSize, &scaleFactorY, &radiusY);
SkPoint srcOffset = SkPoint::Make(-dstBounds.x(), -dstBounds.y());
SkRect localDstBounds = SkRect::MakeWH(dstBounds.width(), dstBounds.height());
SkRect localSrcBounds;
SkRect srcRect;
if (srcBounds) {
srcRect = localSrcBounds = *srcBounds;
srcRect.offset(srcOffset);
srcBounds = &localSrcBounds;
} else {
srcRect = localDstBounds;
}
scale_rect(&srcRect, 1.0f / scaleFactorX, 1.0f / scaleFactorY);
srcRect.roundOut(&srcRect);
scale_rect(&srcRect, static_cast<float>(scaleFactorX),
static_cast<float>(scaleFactorY));
// setup new clip
GrClip clip(localDstBounds);
SkASSERT(kBGRA_8888_GrPixelConfig == srcTexture->config() ||
kRGBA_8888_GrPixelConfig == srcTexture->config() ||
kAlpha_8_GrPixelConfig == srcTexture->config());
GrSurfaceDesc desc;
desc.fFlags = kRenderTarget_GrSurfaceFlag;
desc.fWidth = SkScalarFloorToInt(dstBounds.width());
desc.fHeight = SkScalarFloorToInt(dstBounds.height());
desc.fConfig = srcTexture->config();
GrTexture* dstTexture;
GrTexture* tempTexture;
SkAutoTUnref<GrTexture> temp1, temp2;
temp1.reset(context->textureProvider()->createTexture(desc, constraint));
dstTexture = temp1.get();
if (canClobberSrc) {
tempTexture = srcTexture;
} else {
temp2.reset(context->textureProvider()->createTexture(desc, constraint));
tempTexture = temp2.get();
}
if (nullptr == dstTexture || nullptr == tempTexture) {
return nullptr;
}
SkAutoTUnref<GrDrawContext> srcDrawContext;
for (int i = 1; i < scaleFactorX || i < scaleFactorY; i *= 2) {
GrPaint paint;
SkMatrix matrix;
matrix.setIDiv(srcTexture->width(), srcTexture->height());
SkRect dstRect(srcRect);
if (srcBounds && i == 1) {
SkRect domain;
matrix.mapRect(&domain, *srcBounds);
domain.inset((i < scaleFactorX) ? SK_ScalarHalf / srcTexture->width() : 0.0f,
(i < scaleFactorY) ? SK_ScalarHalf / srcTexture->height() : 0.0f);
SkAutoTUnref<const GrFragmentProcessor> fp(GrTextureDomainEffect::Create(
srcTexture,
matrix,
domain,
GrTextureDomain::kDecal_Mode,
GrTextureParams::kBilerp_FilterMode));
paint.addColorFragmentProcessor(fp);
srcRect.offset(-srcOffset);
srcOffset.set(0, 0);
} else {
GrTextureParams params(SkShader::kClamp_TileMode, GrTextureParams::kBilerp_FilterMode);
paint.addColorTextureProcessor(srcTexture, matrix, params);
}
paint.setPorterDuffXPFactory(SkXfermode::kSrc_Mode);
scale_rect(&dstRect, i < scaleFactorX ? 0.5f : 1.0f,
i < scaleFactorY ? 0.5f : 1.0f);
SkAutoTUnref<GrDrawContext> dstDrawContext(
context->drawContext(dstTexture->asRenderTarget()));
if (!dstDrawContext) {
return nullptr;
}
dstDrawContext->fillRectToRect(clip, paint, SkMatrix::I(), dstRect, srcRect);
srcDrawContext.swap(dstDrawContext);
srcRect = dstRect;
srcTexture = dstTexture;
SkTSwap(dstTexture, tempTexture);
localSrcBounds = srcRect;
}
// For really small blurs (certainly no wider than 5x5 on desktop gpus) it is faster to just
// launch a single non separable kernel vs two launches
srcRect = localDstBounds;
if (sigmaX > 0.0f && sigmaY > 0.0f &&
(2 * radiusX + 1) * (2 * radiusY + 1) <= MAX_KERNEL_SIZE) {
// We shouldn't be scaling because this is a small size blur
SkASSERT((1 == scaleFactorX) && (1 == scaleFactorY));
SkAutoTUnref<GrDrawContext> dstDrawContext(
context->drawContext(dstTexture->asRenderTarget()));
if (!dstDrawContext) {
return nullptr;
}
convolve_gaussian_2d(dstDrawContext, clip, srcRect, srcOffset,
srcTexture, radiusX, radiusY, sigmaX, sigmaY, srcBounds);
srcDrawContext.swap(dstDrawContext);
srcRect.offsetTo(0, 0);
srcTexture = dstTexture;
SkTSwap(dstTexture, tempTexture);
} else {
scale_rect(&srcRect, 1.0f / scaleFactorX, 1.0f / scaleFactorY);
srcRect.roundOut(&srcRect);
const SkIRect srcIRect = srcRect.roundOut();
if (sigmaX > 0.0f) {
if (scaleFactorX > 1) {
// TODO: if we pass in the source draw context we don't need this here
if (!srcDrawContext) {
srcDrawContext.reset(context->drawContext(srcTexture->asRenderTarget()));
if (!srcDrawContext) {
return nullptr;
}
}
// Clear out a radius to the right of the srcRect to prevent the
// X convolution from reading garbage.
clearRect = SkIRect::MakeXYWH(srcIRect.fRight, srcIRect.fTop,
radiusX, srcIRect.height());
srcDrawContext->clear(&clearRect, 0x0, false);
}
SkAutoTUnref<GrDrawContext> dstDrawContext(
context->drawContext(dstTexture->asRenderTarget()));
if (!dstDrawContext) {
return nullptr;
}
convolve_gaussian(dstDrawContext, clip, srcRect,
srcTexture, Gr1DKernelEffect::kX_Direction, radiusX, sigmaX,
srcBounds, srcOffset);
srcDrawContext.swap(dstDrawContext);
srcTexture = dstTexture;
srcRect.offsetTo(0, 0);
SkTSwap(dstTexture, tempTexture);
localSrcBounds = srcRect;
srcOffset.set(0, 0);
}
if (sigmaY > 0.0f) {
if (scaleFactorY > 1 || sigmaX > 0.0f) {
// TODO: if we pass in the source draw context we don't need this here
if (!srcDrawContext) {
srcDrawContext.reset(context->drawContext(srcTexture->asRenderTarget()));
if (!srcDrawContext) {
return nullptr;
}
}
// Clear out a radius below the srcRect to prevent the Y
// convolution from reading garbage.
clearRect = SkIRect::MakeXYWH(srcIRect.fLeft, srcIRect.fBottom,
srcIRect.width(), radiusY);
srcDrawContext->clear(&clearRect, 0x0, false);
}
SkAutoTUnref<GrDrawContext> dstDrawContext(
context->drawContext(dstTexture->asRenderTarget()));
if (!dstDrawContext) {
return nullptr;
}
convolve_gaussian(dstDrawContext, clip, srcRect,
srcTexture, Gr1DKernelEffect::kY_Direction, radiusY, sigmaY,
srcBounds, srcOffset);
srcDrawContext.swap(dstDrawContext);
srcTexture = dstTexture;
srcRect.offsetTo(0, 0);
SkTSwap(dstTexture, tempTexture);
}
}
const SkIRect srcIRect = srcRect.roundOut();
if (scaleFactorX > 1 || scaleFactorY > 1) {
SkASSERT(srcDrawContext);
// Clear one pixel to the right and below, to accommodate bilinear
// upsampling.
clearRect = SkIRect::MakeXYWH(srcIRect.fLeft, srcIRect.fBottom,
srcIRect.width() + 1, 1);
srcDrawContext->clear(&clearRect, 0x0, false);
clearRect = SkIRect::MakeXYWH(srcIRect.fRight, srcIRect.fTop,
1, srcIRect.height());
srcDrawContext->clear(&clearRect, 0x0, false);
SkMatrix matrix;
matrix.setIDiv(srcTexture->width(), srcTexture->height());
GrPaint paint;
// FIXME: this should be mitchell, not bilinear.
GrTextureParams params(SkShader::kClamp_TileMode, GrTextureParams::kBilerp_FilterMode);
paint.addColorTextureProcessor(srcTexture, matrix, params);
paint.setPorterDuffXPFactory(SkXfermode::kSrc_Mode);
SkRect dstRect(srcRect);
scale_rect(&dstRect, (float) scaleFactorX, (float) scaleFactorY);
SkAutoTUnref<GrDrawContext> dstDrawContext(
context->drawContext(dstTexture->asRenderTarget()));
if (!dstDrawContext) {
return nullptr;
}
dstDrawContext->fillRectToRect(clip, paint, SkMatrix::I(), dstRect, srcRect);
srcDrawContext.swap(dstDrawContext);
srcRect = dstRect;
srcTexture = dstTexture;
SkTSwap(dstTexture, tempTexture);
}
return SkRef(srcTexture);
}
