/*
* Copyright 2016 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkArenaAlloc.h"
#include "SkBlendModePriv.h"
#include "SkBlitter.h"
#include "SkColor.h"
#include "SkColorFilter.h"
#include "SkColorSpacePriv.h"
#include "SkColorSpaceXformer.h"
#include "SkColorSpaceXformSteps.h"
#include "SkOpts.h"
#include "SkRasterPipeline.h"
#include "SkShader.h"
#include "SkShaderBase.h"
#include "SkTo.h"
#include "SkUtils.h"
class SkRasterPipelineBlitter final : public SkBlitter {
public:
// This is our common entrypoint for creating the blitter once we've sorted out shaders.
static SkBlitter* Create(const SkPixmap&, const SkPaint&, SkArenaAlloc*,
const SkRasterPipeline& shaderPipeline,
bool is_opaque, bool is_constant);
SkRasterPipelineBlitter(SkPixmap dst,
SkBlendMode blend,
SkArenaAlloc* alloc)
: fDst(dst)
, fBlend(blend)
, fAlloc(alloc)
, fColorPipeline(alloc)
{}
void blitH (int x, int y, int w) override;
void blitAntiH (int x, int y, const SkAlpha[], const int16_t[]) override;
void blitAntiH2(int x, int y, U8CPU a0, U8CPU a1) override;
void blitAntiV2(int x, int y, U8CPU a0, U8CPU a1) override;
void blitMask (const SkMask&, const SkIRect& clip) override;
void blitRect (int x, int y, int width, int height) override;
void blitV (int x, int y, int height, SkAlpha alpha) override;
private:
void append_load_dst (SkRasterPipeline*) const;
void append_store (SkRasterPipeline*) const;
SkPixmap fDst;
SkBlendMode fBlend;
SkArenaAlloc* fAlloc;
SkRasterPipeline fColorPipeline;
SkRasterPipeline_MemoryCtx
fDstPtr = {nullptr,0}, // Always points to the top-left of fDst.
fMaskPtr = {nullptr,0}; // Updated each call to blitMask().
SkRasterPipeline_EmbossCtx fEmbossCtx; // Used only for k3D_Format masks.
// We may be able to specialize blitH() or blitRect() into a memset.
void (*fMemset2D)(SkPixmap*, int x,int y, int w,int h, uint64_t color) = nullptr;
uint64_t fMemsetColor = 0; // Big enough for largest memsettable dst format, F16.
// Built lazily on first use.
std::function<void(size_t, size_t, size_t, size_t)> fBlitRect,
fBlitAntiH,
fBlitMaskA8,
fBlitMaskLCD16,
fBlitMask3D;
// These values are pointed to by the blit pipelines above,
// which allows us to adjust them from call to call.
float fCurrentCoverage = 0.0f;
float fDitherRate = 0.0f;
typedef SkBlitter INHERITED;
};
SkBlitter* SkCreateRasterPipelineBlitter(const SkPixmap& dst,
const SkPaint& paint,
const SkMatrix& ctm,
SkArenaAlloc* alloc) {
// For legacy/SkColorSpaceXformCanvas to keep working,
// we need to sometimes still need to distinguish null dstCS from sRGB.
#if 0
SkColorSpace* dstCS = dst.colorSpace() ? dst.colorSpace()
: sk_srgb_singleton();
#else
SkColorSpace* dstCS = dst.colorSpace();
#endif
SkColorType dstCT = dst.colorType();
SkColor4f paintColor = paint.getColor4f();
SkColorSpaceXformSteps(sk_srgb_singleton(), kUnpremul_SkAlphaType,
dstCS, kUnpremul_SkAlphaType).apply(paintColor.vec());
auto shader = as_SB(paint.getShader());
SkRasterPipeline_<256> shaderPipeline;
if (!shader) {
// Having no shader makes things nice and easy... just use the paint color.
shaderPipeline.append_constant_color(alloc, paintColor.premul().vec());
bool is_opaque = paintColor.fA == 1.0f,
is_constant = true;
return SkRasterPipelineBlitter::Create(dst, paint, alloc,
shaderPipeline, is_opaque, is_constant);
}
bool is_opaque = shader->isOpaque() && paintColor.fA == 1.0f;
bool is_constant = shader->isConstant();
if (shader->appendStages({&shaderPipeline, alloc, dstCT, dstCS, paint, nullptr, ctm})) {
if (paintColor.fA != 1.0f) {
shaderPipeline.append(SkRasterPipeline::scale_1_float,
alloc->make<float>(paintColor.fA));
}
return SkRasterPipelineBlitter::Create(dst, paint, alloc,
shaderPipeline, is_opaque, is_constant);
}
// The shader has opted out of drawing anything.
return alloc->make<SkNullBlitter>();
}
SkBlitter* SkCreateRasterPipelineBlitter(const SkPixmap& dst,
const SkPaint& paint,
const SkRasterPipeline& shaderPipeline,
bool is_opaque,
SkArenaAlloc* alloc) {
bool is_constant = false; // If this were the case, it'd be better to just set a paint color.
return SkRasterPipelineBlitter::Create(dst, paint, alloc,
shaderPipeline, is_opaque, is_constant);
}
SkBlitter* SkRasterPipelineBlitter::Create(const SkPixmap& dst,
const SkPaint& paint,
SkArenaAlloc* alloc,
const SkRasterPipeline& shaderPipeline,
bool is_opaque,
bool is_constant) {
auto blitter = alloc->make<SkRasterPipelineBlitter>(dst,
paint.getBlendMode(),
alloc);
// Our job in this factory is to fill out the blitter's color pipeline.
// This is the common front of the full blit pipelines, each constructed lazily on first use.
// The full blit pipelines handle reading and writing the dst, blending, coverage, dithering.
auto colorPipeline = &blitter->fColorPipeline;
// Let's get the shader in first.
colorPipeline->extend(shaderPipeline);
// If there's a color filter it comes next.
if (auto colorFilter = paint.getColorFilter()) {
colorFilter->appendStages(colorPipeline, dst.colorSpace(), alloc, is_opaque);
is_opaque = is_opaque && (colorFilter->getFlags() & SkColorFilter::kAlphaUnchanged_Flag);
}
// Not all formats make sense to dither (think, F16). We set their dither rate
// to zero. We need to decide if we're going to dither now to keep is_constant accurate.
if (paint.isDither()) {
switch (dst.info().colorType()) {
default: blitter->fDitherRate = 0.0f; break;
case kARGB_4444_SkColorType: blitter->fDitherRate = 1/15.0f; break;
case kRGB_565_SkColorType: blitter->fDitherRate = 1/63.0f; break;
case kGray_8_SkColorType:
case kRGB_888x_SkColorType:
case kRGBA_8888_SkColorType:
case kBGRA_8888_SkColorType: blitter->fDitherRate = 1/255.0f; break;
case kRGB_101010x_SkColorType:
case kRGBA_1010102_SkColorType: blitter->fDitherRate = 1/1023.0f; break;
}
// TODO: for constant colors, we could try to measure the effect of dithering, and if
// it has no value (i.e. all variations result in the same 32bit color, then we
// could disable it (for speed, by not adding the stage).
}
is_constant = is_constant && (blitter->fDitherRate == 0.0f);
// We're logically done here. The code between here and return blitter is all optimization.
// A pipeline that's still constant here can collapse back into a constant color.
if (is_constant) {
SkColor4f constantColor;
SkRasterPipeline_MemoryCtx constantColorPtr = { &constantColor, 0 };
colorPipeline->append_gamut_clamp_if_normalized(dst.info());
colorPipeline->append(SkRasterPipeline::store_f32, &constantColorPtr);
colorPipeline->run(0,0,1,1);
colorPipeline->reset();
colorPipeline->append_constant_color(alloc, constantColor);
is_opaque = constantColor.fA == 1.0f;
}
// We can strength-reduce SrcOver into Src when opaque.
if (is_opaque && blitter->fBlend == SkBlendMode::kSrcOver) {
blitter->fBlend = SkBlendMode::kSrc;
}
// When we're drawing a constant color in Src mode, we can sometimes just memset.
// (The previous two optimizations help find more opportunities for this one.)
if (is_constant && blitter->fBlend == SkBlendMode::kSrc) {
// Run our color pipeline all the way through to produce what we'd memset when we can.
// Not all blits can memset, so we need to keep colorPipeline too.
SkRasterPipeline_<256> p;
p.extend(*colorPipeline);
p.append_gamut_clamp_if_normalized(dst.info());
blitter->fDstPtr = SkRasterPipeline_MemoryCtx{&blitter->fMemsetColor, 0};
blitter->append_store(&p);
p.run(0,0,1,1);
switch (blitter->fDst.shiftPerPixel()) {
case 0: blitter->fMemset2D = [](SkPixmap* dst, int x,int y, int w,int h, uint64_t c) {
void* p = dst->writable_addr(x,y);
while (h --> 0) {
memset(p, c, w);
p = SkTAddOffset<void>(p, dst->rowBytes());
}
}; break;
case 1: blitter->fMemset2D = [](SkPixmap* dst, int x,int y, int w,int h, uint64_t c) {
uint16_t* p = dst->writable_addr16(x,y);
auto fn = SkOpts::memset16;
while (h --> 0) {
fn(p, c, w);
p = SkTAddOffset<uint16_t>(p, dst->rowBytes());
}
}; break;
case 2: blitter->fMemset2D = [](SkPixmap* dst, int x,int y, int w,int h, uint64_t c) {
uint32_t* p = dst->writable_addr32(x,y);
auto fn = SkOpts::memset32;
while (h --> 0) {
fn(p, c, w);
p = SkTAddOffset<uint32_t>(p, dst->rowBytes());
}
}; break;
case 3: blitter->fMemset2D = [](SkPixmap* dst, int x,int y, int w,int h, uint64_t c) {
uint64_t* p = dst->writable_addr64(x,y);
auto fn = SkOpts::memset64;
while (h --> 0) {
fn(p, c, w);
p = SkTAddOffset<uint64_t>(p, dst->rowBytes());
}
}; break;
// TODO(F32)?
}
}
blitter->fDstPtr = SkRasterPipeline_MemoryCtx{
blitter->fDst.writable_addr(),
blitter->fDst.rowBytesAsPixels(),
};
return blitter;
}
void SkRasterPipelineBlitter::append_load_dst(SkRasterPipeline* p) const {
p->append_load_dst(fDst.info().colorType(), &fDstPtr);
if (fDst.info().alphaType() == kUnpremul_SkAlphaType) {
p->append(SkRasterPipeline::premul_dst);
}
}
void SkRasterPipelineBlitter::append_store(SkRasterPipeline* p) const {
if (fDst.info().alphaType() == kUnpremul_SkAlphaType) {
p->append(SkRasterPipeline::unpremul);
}
if (fDitherRate > 0.0f) {
p->append(SkRasterPipeline::dither, &fDitherRate);
}
p->append_store(fDst.info().colorType(), &fDstPtr);
}
void SkRasterPipelineBlitter::blitH(int x, int y, int w) {
this->blitRect(x,y,w,1);
}
void SkRasterPipelineBlitter::blitRect(int x, int y, int w, int h) {
if (fMemset2D) {
fMemset2D(&fDst, x,y, w,h, fMemsetColor);
return;
}
if (!fBlitRect) {
SkRasterPipeline p(fAlloc);
p.extend(fColorPipeline);
p.append_gamut_clamp_if_normalized(fDst.info());
if (fBlend == SkBlendMode::kSrcOver
&& (fDst.info().colorType() == kRGBA_8888_SkColorType ||
fDst.info().colorType() == kBGRA_8888_SkColorType)
&& !fDst.colorSpace()
&& fDst.info().alphaType() != kUnpremul_SkAlphaType
&& fDitherRate == 0.0f) {
if (fDst.info().colorType() == kBGRA_8888_SkColorType) {
p.append(SkRasterPipeline::swap_rb);
}
p.append(SkRasterPipeline::srcover_rgba_8888, &fDstPtr);
} else {
if (fBlend != SkBlendMode::kSrc) {
this->append_load_dst(&p);
SkBlendMode_AppendStages(fBlend, &p);
}
this->append_store(&p);
}
fBlitRect = p.compile();
}
fBlitRect(x,y,w,h);
}
void SkRasterPipelineBlitter::blitAntiH(int x, int y, const SkAlpha aa[], const int16_t runs[]) {
if (!fBlitAntiH) {
SkRasterPipeline p(fAlloc);
p.extend(fColorPipeline);
p.append_gamut_clamp_if_normalized(fDst.info());
if (SkBlendMode_ShouldPreScaleCoverage(fBlend, /*rgb_coverage=*/false)) {
p.append(SkRasterPipeline::scale_1_float, &fCurrentCoverage);
this->append_load_dst(&p);
SkBlendMode_AppendStages(fBlend, &p);
} else {
this->append_load_dst(&p);
SkBlendMode_AppendStages(fBlend, &p);
p.append(SkRasterPipeline::lerp_1_float, &fCurrentCoverage);
}
this->append_store(&p);
fBlitAntiH = p.compile();
}
for (int16_t run = *runs; run > 0; run = *runs) {
switch (*aa) {
case 0x00: break;
case 0xff: this->blitH(x,y,run); break;
default:
fCurrentCoverage = *aa * (1/255.0f);
fBlitAntiH(x,y,run,1);
}
x += run;
runs += run;
aa += run;
}
}
void SkRasterPipelineBlitter::blitAntiH2(int x, int y, U8CPU a0, U8CPU a1) {
SkIRect clip = {x,y, x+2,y+1};
uint8_t coverage[] = { (uint8_t)a0, (uint8_t)a1 };
SkMask mask;
mask.fImage = coverage;
mask.fBounds = clip;
mask.fRowBytes = 2;
mask.fFormat = SkMask::kA8_Format;
this->blitMask(mask, clip);
}
void SkRasterPipelineBlitter::blitAntiV2(int x, int y, U8CPU a0, U8CPU a1) {
SkIRect clip = {x,y, x+1,y+2};
uint8_t coverage[] = { (uint8_t)a0, (uint8_t)a1 };
SkMask mask;
mask.fImage = coverage;
mask.fBounds = clip;
mask.fRowBytes = 1;
mask.fFormat = SkMask::kA8_Format;
this->blitMask(mask, clip);
}
void SkRasterPipelineBlitter::blitV(int x, int y, int height, SkAlpha alpha) {
SkIRect clip = {x,y, x+1,y+height};
SkMask mask;
mask.fImage = α
mask.fBounds = clip;
mask.fRowBytes = 0; // so we reuse the 1 "row" for all of height
mask.fFormat = SkMask::kA8_Format;
this->blitMask(mask, clip);
}
void SkRasterPipelineBlitter::blitMask(const SkMask& mask, const SkIRect& clip) {
if (mask.fFormat == SkMask::kBW_Format) {
// TODO: native BW masks?
return INHERITED::blitMask(mask, clip);
}
// ARGB and SDF masks shouldn't make it here.
SkASSERT(mask.fFormat == SkMask::kA8_Format
|| mask.fFormat == SkMask::kLCD16_Format
|| mask.fFormat == SkMask::k3D_Format);
auto extract_mask_plane = [&mask](int plane, SkRasterPipeline_MemoryCtx* ctx) {
// LCD is 16-bit per pixel; A8 and 3D are 8-bit per pixel.
size_t bpp = mask.fFormat == SkMask::kLCD16_Format ? 2 : 1;
// Select the right mask plane. Usually plane == 0 and this is just mask.fImage.
auto ptr = (uintptr_t)mask.fImage
+ plane * mask.computeImageSize();
// Update ctx to point "into" this current mask, but lined up with fDstPtr at (0,0).
// This sort of trickery upsets UBSAN (pointer-overflow) so our ptr must be a uintptr_t.
// mask.fRowBytes is a uint32_t, which would break our addressing math on 64-bit builds.
size_t rowBytes = mask.fRowBytes;
ctx->stride = rowBytes / bpp;
ctx->pixels = (void*)(ptr - mask.fBounds.left() * bpp
- mask.fBounds.top() * rowBytes);
};
extract_mask_plane(0, &fMaskPtr);
if (mask.fFormat == SkMask::k3D_Format) {
extract_mask_plane(1, &fEmbossCtx.mul);
extract_mask_plane(2, &fEmbossCtx.add);
}
// Lazily build whichever pipeline we need, specialized for each mask format.
if (mask.fFormat == SkMask::kA8_Format && !fBlitMaskA8) {
SkRasterPipeline p(fAlloc);
p.extend(fColorPipeline);
p.append_gamut_clamp_if_normalized(fDst.info());
if (SkBlendMode_ShouldPreScaleCoverage(fBlend, /*rgb_coverage=*/false)) {
p.append(SkRasterPipeline::scale_u8, &fMaskPtr);
this->append_load_dst(&p);
SkBlendMode_AppendStages(fBlend, &p);
} else {
this->append_load_dst(&p);
SkBlendMode_AppendStages(fBlend, &p);
p.append(SkRasterPipeline::lerp_u8, &fMaskPtr);
}
this->append_store(&p);
fBlitMaskA8 = p.compile();
}
if (mask.fFormat == SkMask::kLCD16_Format && !fBlitMaskLCD16) {
SkRasterPipeline p(fAlloc);
p.extend(fColorPipeline);
p.append_gamut_clamp_if_normalized(fDst.info());
if (SkBlendMode_ShouldPreScaleCoverage(fBlend, /*rgb_coverage=*/true)) {
// Somewhat unusually, scale_565 needs dst loaded first.
this->append_load_dst(&p);
p.append(SkRasterPipeline::scale_565, &fMaskPtr);
SkBlendMode_AppendStages(fBlend, &p);
} else {
this->append_load_dst(&p);
SkBlendMode_AppendStages(fBlend, &p);
p.append(SkRasterPipeline::lerp_565, &fMaskPtr);
}
this->append_store(&p);
fBlitMaskLCD16 = p.compile();
}
if (mask.fFormat == SkMask::k3D_Format && !fBlitMask3D) {
SkRasterPipeline p(fAlloc);
p.extend(fColorPipeline);
// This bit is where we differ from kA8_Format:
p.append(SkRasterPipeline::emboss, &fEmbossCtx);
// Now onward just as kA8.
p.append_gamut_clamp_if_normalized(fDst.info());
if (SkBlendMode_ShouldPreScaleCoverage(fBlend, /*rgb_coverage=*/false)) {
p.append(SkRasterPipeline::scale_u8, &fMaskPtr);
this->append_load_dst(&p);
SkBlendMode_AppendStages(fBlend, &p);
} else {
this->append_load_dst(&p);
SkBlendMode_AppendStages(fBlend, &p);
p.append(SkRasterPipeline::lerp_u8, &fMaskPtr);
}
this->append_store(&p);
fBlitMask3D = p.compile();
}
std::function<void(size_t,size_t,size_t,size_t)>* blitter = nullptr;
switch (mask.fFormat) {
case SkMask::kA8_Format: blitter = &fBlitMaskA8; break;
case SkMask::kLCD16_Format: blitter = &fBlitMaskLCD16; break;
case SkMask::k3D_Format: blitter = &fBlitMask3D; break;
default:
SkASSERT(false);
return;
}
SkASSERT(blitter);
(*blitter)(clip.left(),clip.top(), clip.width(),clip.height());
}