/*
* Copyright 2017 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 "SkAutoBlitterChoose.h"
#include "SkComposeShader.h"
#include "SkConvertPixels.h"
#include "SkDraw.h"
#include "SkNx.h"
#include "SkRasterClip.h"
#include "SkScan.h"
#include "SkShaderBase.h"
#include "SkString.h"
#include "SkVertState.h"
#include "SkArenaAlloc.h"
#include "SkCoreBlitters.h"
struct Matrix43 {
float fMat[12]; // column major
Sk4f map(float x, float y) const {
return Sk4f::Load(&fMat[0]) * x + Sk4f::Load(&fMat[4]) * y + Sk4f::Load(&fMat[8]);
}
void setConcat(const Matrix43& a, const SkMatrix& b) {
fMat[ 0] = a.dot(0, b.getScaleX(), b.getSkewY());
fMat[ 1] = a.dot(1, b.getScaleX(), b.getSkewY());
fMat[ 2] = a.dot(2, b.getScaleX(), b.getSkewY());
fMat[ 3] = a.dot(3, b.getScaleX(), b.getSkewY());
fMat[ 4] = a.dot(0, b.getSkewX(), b.getScaleY());
fMat[ 5] = a.dot(1, b.getSkewX(), b.getScaleY());
fMat[ 6] = a.dot(2, b.getSkewX(), b.getScaleY());
fMat[ 7] = a.dot(3, b.getSkewX(), b.getScaleY());
fMat[ 8] = a.dot(0, b.getTranslateX(), b.getTranslateY()) + a.fMat[ 8];
fMat[ 9] = a.dot(1, b.getTranslateX(), b.getTranslateY()) + a.fMat[ 9];
fMat[10] = a.dot(2, b.getTranslateX(), b.getTranslateY()) + a.fMat[10];
fMat[11] = a.dot(3, b.getTranslateX(), b.getTranslateY()) + a.fMat[11];
}
private:
float dot(int index, float x, float y) const {
return fMat[index + 0] * x + fMat[index + 4] * y;
}
};
static SkScan::HairRCProc ChooseHairProc(bool doAntiAlias) {
return doAntiAlias ? SkScan::AntiHairLine : SkScan::HairLine;
}
static bool SK_WARN_UNUSED_RESULT
texture_to_matrix(const VertState& state, const SkPoint verts[], const SkPoint texs[],
SkMatrix* matrix) {
SkPoint src[3], dst[3];
src[0] = texs[state.f0];
src[1] = texs[state.f1];
src[2] = texs[state.f2];
dst[0] = verts[state.f0];
dst[1] = verts[state.f1];
dst[2] = verts[state.f2];
return matrix->setPolyToPoly(src, dst, 3);
}
class SkTriColorShader : public SkShaderBase {
public:
SkTriColorShader(bool isOpaque) : fIsOpaque(isOpaque) {}
Matrix43* getMatrix43() { return &fM43; }
bool isOpaque() const override { return fIsOpaque; }
protected:
#ifdef SK_ENABLE_LEGACY_SHADERCONTEXT
Context* onMakeContext(const ContextRec& rec, SkArenaAlloc* alloc) const override {
return nullptr;
}
#endif
bool onAppendStages(const StageRec& rec) const override {
rec.fPipeline->append(SkRasterPipeline::seed_shader);
rec.fPipeline->append(SkRasterPipeline::matrix_4x3, &fM43);
return true;
}
private:
// For serialization. This will never be called.
Factory getFactory() const override { return nullptr; }
const char* getTypeName() const override { return nullptr; }
Matrix43 fM43;
const bool fIsOpaque;
typedef SkShaderBase INHERITED;
};
static bool SK_WARN_UNUSED_RESULT
update_tricolor_matrix(const SkMatrix& ctmInv, const SkPoint pts[], const SkPMColor4f colors[],
int index0, int index1, int index2, Matrix43* result) {
SkMatrix m, im;
m.reset();
m.set(0, pts[index1].fX - pts[index0].fX);
m.set(1, pts[index2].fX - pts[index0].fX);
m.set(2, pts[index0].fX);
m.set(3, pts[index1].fY - pts[index0].fY);
m.set(4, pts[index2].fY - pts[index0].fY);
m.set(5, pts[index0].fY);
if (!m.invert(&im)) {
return false;
}
SkMatrix dstToUnit;
dstToUnit.setConcat(im, ctmInv);
Sk4f c0 = Sk4f::Load(colors[index0].vec()),
c1 = Sk4f::Load(colors[index1].vec()),
c2 = Sk4f::Load(colors[index2].vec());
Matrix43 colorm;
(c1 - c0).store(&colorm.fMat[0]);
(c2 - c0).store(&colorm.fMat[4]);
c0.store(&colorm.fMat[8]);
result->setConcat(colorm, dstToUnit);
return true;
}
// Convert the SkColors into float colors. The conversion depends on some conditions:
// - If the pixmap has a dst colorspace, we have to be "color-correct".
// Do we map into dst-colorspace before or after we interpolate?
// - We have to decide when to apply per-color alpha (before or after we interpolate)
//
// For now, we will take a simple approach, but recognize this is just a start:
// - convert colors into dst colorspace before interpolation (matches gradients)
// - apply per-color alpha before interpolation (matches old version of vertices)
//
static SkPMColor4f* convert_colors(const SkColor src[], int count, SkColorSpace* deviceCS,
SkArenaAlloc* alloc) {
SkPMColor4f* dst = alloc->makeArray<SkPMColor4f>(count);
SkImageInfo srcInfo = SkImageInfo::Make(count, 1, kBGRA_8888_SkColorType,
kUnpremul_SkAlphaType, SkColorSpace::MakeSRGB());
SkImageInfo dstInfo = SkImageInfo::Make(count, 1, kRGBA_F32_SkColorType,
kPremul_SkAlphaType, sk_ref_sp(deviceCS));
SkConvertPixels(dstInfo, dst, 0, srcInfo, src, 0);
return dst;
}
static bool compute_is_opaque(const SkColor colors[], int count) {
uint32_t c = ~0;
for (int i = 0; i < count; ++i) {
c &= colors[i];
}
return SkColorGetA(c) == 0xFF;
}
void SkDraw::drawVertices(SkVertices::VertexMode vmode, int vertexCount,
const SkPoint vertices[], const SkPoint textures[],
const SkColor colors[], const SkVertices::BoneIndices boneIndices[],
const SkVertices::BoneWeights boneWeights[], SkBlendMode bmode,
const uint16_t indices[], int indexCount,
const SkPaint& paint, const SkVertices::Bone bones[],
int boneCount) const {
SkASSERT(0 == vertexCount || vertices);
// abort early if there is nothing to draw
if (vertexCount < 3 || (indices && indexCount < 3) || fRC->isEmpty()) {
return;
}
SkMatrix ctmInv;
if (!fMatrix->invert(&ctmInv)) {
return;
}
// make textures and shader mutually consistent
SkShader* shader = paint.getShader();
if (!(shader && textures)) {
shader = nullptr;
textures = nullptr;
}
// We can simplify things for certain blendmodes. This is for speed, and SkComposeShader
// itself insists we don't pass kSrc or kDst to it.
//
if (colors && textures) {
switch (bmode) {
case SkBlendMode::kSrc:
colors = nullptr;
break;
case SkBlendMode::kDst:
textures = nullptr;
break;
default: break;
}
}
// we don't use the shader if there are no textures
if (!textures) {
shader = nullptr;
}
constexpr size_t kDefVertexCount = 16;
constexpr size_t kOuterSize = sizeof(SkTriColorShader) +
sizeof(SkComposeShader) +
(2 * sizeof(SkPoint) + sizeof(SkColor4f)) * kDefVertexCount;
SkSTArenaAlloc<kOuterSize> outerAlloc;
// deform vertices using the skeleton if it is passed in
if (bones && boneCount) {
// allocate space for the deformed vertices
SkPoint* deformed = outerAlloc.makeArray<SkPoint>(vertexCount);
// deform the vertices
if (boneIndices && boneWeights) {
for (int i = 0; i < vertexCount; i ++) {
const SkVertices::BoneIndices& indices = boneIndices[i];
const SkVertices::BoneWeights& weights = boneWeights[i];
// apply the world transform
SkPoint worldPoint = bones[0].mapPoint(vertices[i]);
// apply bone deformations
deformed[i] = SkPoint::Make(0.0f, 0.0f);
for (uint32_t j = 0; j < 4; j ++) {
// get the attachment data
uint32_t index = indices[j];
float weight = weights[j];
// skip the bone if there is no weight
if (weight == 0.0f) {
continue;
}
SkASSERT(index != 0);
// deformed += M * v * w
deformed[i] += bones[index].mapPoint(worldPoint) * weight;
}
}
} else {
// no bones, so only apply world transform
SkMatrix worldTransform = SkMatrix::I();
worldTransform.setAffine(bones[0].values);
worldTransform.mapPoints(deformed, vertices, vertexCount);
}
// change the vertices to point to deformed
vertices = deformed;
}
SkPoint* devVerts = outerAlloc.makeArray<SkPoint>(vertexCount);
fMatrix->mapPoints(devVerts, vertices, vertexCount);
{
SkRect bounds;
// this also sets bounds to empty if we see a non-finite value
bounds.set(devVerts, vertexCount);
if (bounds.isEmpty()) {
return;
}
}
VertState state(vertexCount, indices, indexCount);
VertState::Proc vertProc = state.chooseProc(vmode);
if (colors || textures) {
SkPMColor4f* dstColors = nullptr;
Matrix43* matrix43 = nullptr;
if (colors) {
dstColors = convert_colors(colors, vertexCount, fDst.colorSpace(), &outerAlloc);
SkTriColorShader* triShader = outerAlloc.make<SkTriColorShader>(
compute_is_opaque(colors,
vertexCount));
matrix43 = triShader->getMatrix43();
if (shader) {
shader = outerAlloc.make<SkComposeShader>(sk_ref_sp(triShader), sk_ref_sp(shader),
bmode, 1);
} else {
shader = triShader;
}
}
SkPaint p(paint);
p.setShader(sk_ref_sp(shader));
if (!textures) { // only tricolor shader
SkASSERT(matrix43);
auto blitter = SkCreateRasterPipelineBlitter(fDst, p, *fMatrix, &outerAlloc);
while (vertProc(&state)) {
if (!update_tricolor_matrix(ctmInv, vertices, dstColors,
state.f0, state.f1, state.f2,
matrix43)) {
continue;
}
SkPoint tmp[] = {
devVerts[state.f0], devVerts[state.f1], devVerts[state.f2]
};
SkScan::FillTriangle(tmp, *fRC, blitter);
}
} else {
while (vertProc(&state)) {
SkSTArenaAlloc<2048> innerAlloc;
const SkMatrix* ctm = fMatrix;
SkMatrix tmpCtm;
if (textures) {
SkMatrix localM;
if (!texture_to_matrix(state, vertices, textures, &localM)) {
continue;
}
tmpCtm = SkMatrix::Concat(*fMatrix, localM);
ctm = &tmpCtm;
}
if (matrix43 && !update_tricolor_matrix(ctmInv, vertices, dstColors,
state.f0, state.f1, state.f2,
matrix43)) {
continue;
}
SkPoint tmp[] = {
devVerts[state.f0], devVerts[state.f1], devVerts[state.f2]
};
auto blitter = SkCreateRasterPipelineBlitter(fDst, p, *ctm, &innerAlloc);
SkScan::FillTriangle(tmp, *fRC, blitter);
}
}
} else {
// no colors[] and no texture, stroke hairlines with paint's color.
SkPaint p;
p.setStyle(SkPaint::kStroke_Style);
SkAutoBlitterChoose blitter(*this, nullptr, p);
// Abort early if we failed to create a shader context.
if (blitter->isNullBlitter()) {
return;
}
SkScan::HairRCProc hairProc = ChooseHairProc(paint.isAntiAlias());
const SkRasterClip& clip = *fRC;
while (vertProc(&state)) {
SkPoint array[] = {
devVerts[state.f0], devVerts[state.f1], devVerts[state.f2], devVerts[state.f0]
};
hairProc(array, 4, clip, blitter.get());
}
}
}