/*
* Copyright 2013 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkGpuBlurUtils.h"
#include "SkRect.h"
#if SK_SUPPORT_GPU
#include "effects/GrConvolutionEffect.h"
#include "effects/GrMatrixConvolutionEffect.h"
#include "GrContext.h"
#include "GrCaps.h"
#include "GrDrawContext.h"
#endif
namespace SkGpuBlurUtils {
#if SK_SUPPORT_GPU
#define MAX_BLUR_SIGMA 4.0f
static void scale_rect(SkRect* rect, float xScale, float yScale) {
rect->fLeft = SkScalarMul(rect->fLeft, xScale);
rect->fTop = SkScalarMul(rect->fTop, yScale);
rect->fRight = SkScalarMul(rect->fRight, xScale);
rect->fBottom = SkScalarMul(rect->fBottom, yScale);
}
static float adjust_sigma(float sigma, int maxTextureSize, int *scaleFactor, int *radius) {
*scaleFactor = 1;
while (sigma > MAX_BLUR_SIGMA) {
*scaleFactor *= 2;
sigma *= 0.5f;
if (*scaleFactor > maxTextureSize) {
*scaleFactor = maxTextureSize;
sigma = MAX_BLUR_SIGMA;
}
}
*radius = static_cast<int>(ceilf(sigma * 3.0f));
SkASSERT(*radius <= GrConvolutionEffect::kMaxKernelRadius);
return sigma;
}
static void convolve_gaussian_1d(GrDrawContext* drawContext,
const GrClip& clip,
const SkRect& dstRect,
const SkPoint& srcOffset,
GrTexture* texture,
Gr1DKernelEffect::Direction direction,
int radius,
float sigma,
bool useBounds,
float bounds[2]) {
GrPaint paint;
SkAutoTUnref<GrFragmentProcessor> conv(GrConvolutionEffect::CreateGaussian(
texture, direction, radius, sigma, useBounds, bounds));
paint.addColorFragmentProcessor(conv);
paint.setPorterDuffXPFactory(SkXfermode::kSrc_Mode);
SkMatrix localMatrix = SkMatrix::MakeTrans(-srcOffset.x(), -srcOffset.y());
drawContext->fillRectWithLocalMatrix(clip, paint, SkMatrix::I(), dstRect, localMatrix);
}
static void convolve_gaussian_2d(GrDrawContext* drawContext,
const GrClip& clip,
const SkRect& dstRect,
const SkPoint& srcOffset,
GrTexture* texture,
int radiusX,
int radiusY,
SkScalar sigmaX,
SkScalar sigmaY,
const SkRect* srcBounds) {
SkMatrix localMatrix = SkMatrix::MakeTrans(-srcOffset.x(), -srcOffset.y());
SkISize size = SkISize::Make(2 * radiusX + 1, 2 * radiusY + 1);
SkIPoint kernelOffset = SkIPoint::Make(radiusX, radiusY);
GrPaint paint;
SkIRect bounds;
if (srcBounds) {
srcBounds->roundOut(&bounds);
} else {
bounds.setEmpty();
}
SkAutoTUnref<GrFragmentProcessor> conv(GrMatrixConvolutionEffect::CreateGaussian(
texture, bounds, size, 1.0, 0.0, kernelOffset,
srcBounds ? GrTextureDomain::kDecal_Mode : GrTextureDomain::kIgnore_Mode,
true, sigmaX, sigmaY));
paint.addColorFragmentProcessor(conv);
paint.setPorterDuffXPFactory(SkXfermode::kSrc_Mode);
drawContext->fillRectWithLocalMatrix(clip, paint, SkMatrix::I(), dstRect, localMatrix);
}
static void convolve_gaussian(GrDrawContext* drawContext,
const GrClip& clip,
const SkRect& srcRect,
GrTexture* texture,
Gr1DKernelEffect::Direction direction,
int radius,
float sigma,
const SkRect* srcBounds,
const SkPoint& srcOffset) {
float bounds[2] = { 0.0f, 1.0f };
SkRect dstRect = SkRect::MakeWH(srcRect.width(), srcRect.height());
if (!srcBounds) {
convolve_gaussian_1d(drawContext, clip, dstRect, srcOffset, texture,
direction, radius, sigma, false, bounds);
return;
}
SkRect midRect = *srcBounds, leftRect, rightRect;
midRect.offset(srcOffset);
SkIRect topRect, bottomRect;
SkScalar rad = SkIntToScalar(radius);
if (direction == Gr1DKernelEffect::kX_Direction) {
bounds[0] = SkScalarToFloat(srcBounds->left()) / texture->width();
bounds[1] = SkScalarToFloat(srcBounds->right()) / texture->width();
SkRect::MakeLTRB(0, 0, dstRect.right(), midRect.top()).roundOut(&topRect);
SkRect::MakeLTRB(0, midRect.bottom(), dstRect.right(), dstRect.bottom())
.roundOut(&bottomRect);
midRect.inset(rad, 0);
leftRect = SkRect::MakeLTRB(0, midRect.top(), midRect.left(), midRect.bottom());
rightRect =
SkRect::MakeLTRB(midRect.right(), midRect.top(), dstRect.width(), midRect.bottom());
dstRect.fTop = midRect.top();
dstRect.fBottom = midRect.bottom();
} else {
bounds[0] = SkScalarToFloat(srcBounds->top()) / texture->height();
bounds[1] = SkScalarToFloat(srcBounds->bottom()) / texture->height();
SkRect::MakeLTRB(0, 0, midRect.left(), dstRect.bottom()).roundOut(&topRect);
SkRect::MakeLTRB(midRect.right(), 0, dstRect.right(), dstRect.bottom())
.roundOut(&bottomRect);;
midRect.inset(0, rad);
leftRect = SkRect::MakeLTRB(midRect.left(), 0, midRect.right(), midRect.top());
rightRect =
SkRect::MakeLTRB(midRect.left(), midRect.bottom(), midRect.right(), dstRect.height());
dstRect.fLeft = midRect.left();
dstRect.fRight = midRect.right();
}
if (!topRect.isEmpty()) {
drawContext->clear(&topRect, 0, false);
}
if (!bottomRect.isEmpty()) {
drawContext->clear(&bottomRect, 0, false);
}
if (midRect.isEmpty()) {
// Blur radius covers srcBounds; use bounds over entire draw
convolve_gaussian_1d(drawContext, clip, dstRect, srcOffset, texture,
direction, radius, sigma, true, bounds);
} else {
// Draw right and left margins with bounds; middle without.
convolve_gaussian_1d(drawContext, clip, leftRect, srcOffset, texture,
direction, radius, sigma, true, bounds);
convolve_gaussian_1d(drawContext, clip, rightRect, srcOffset, texture,
direction, radius, sigma, true, bounds);
convolve_gaussian_1d(drawContext, clip, midRect, srcOffset, texture,
direction, radius, sigma, false, bounds);
}
}
GrTexture* GaussianBlur(GrContext* context,
GrTexture* srcTexture,
bool canClobberSrc,
const SkRect& dstBounds,
const SkRect* srcBounds,
float sigmaX,
float sigmaY) {
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()->createApproxTexture(desc));
dstTexture = temp1.get();
if (canClobberSrc) {
tempTexture = srcTexture;
} else {
temp2.reset(context->textureProvider()->createApproxTexture(desc));
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);
}
#endif
}