blob: 1e364ef8e226e85f1b8299f1310c6e83c8f2e1a9 [file] [log] [blame]
/*
* 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 "include/core/SkVertices.h"
#include "include/core/SkData.h"
#include "include/private/SkTo.h"
#include "src/core/SkCanvasPriv.h"
#include "src/core/SkOpts.h"
#include "src/core/SkReadBuffer.h"
#include "src/core/SkSafeMath.h"
#include "src/core/SkSafeRange.h"
#include "src/core/SkVerticesPriv.h"
#include "src/core/SkWriteBuffer.h"
#include <atomic>
#include <new>
static int32_t next_id() {
static std::atomic<int32_t> nextID{1};
int32_t id;
do {
id = nextID.fetch_add(1, std::memory_order_relaxed);
} while (id == SK_InvalidGenID);
return id;
}
struct SkVertices::Desc {
VertexMode fMode;
int fVertexCount,
fIndexCount;
bool fHasTexs,
fHasColors;
};
struct SkVertices::Sizes {
Sizes(const Desc& desc) {
SkSafeMath safe;
fVSize = safe.mul(desc.fVertexCount, sizeof(SkPoint));
fTSize = desc.fHasTexs ? safe.mul(desc.fVertexCount, sizeof(SkPoint)) : 0;
fCSize = desc.fHasColors ? safe.mul(desc.fVertexCount, sizeof(SkColor)) : 0;
fBuilderTriFanISize = 0;
fISize = safe.mul(desc.fIndexCount, sizeof(uint16_t));
if (kTriangleFan_VertexMode == desc.fMode) {
int numFanTris = 0;
if (desc.fIndexCount) {
fBuilderTriFanISize = fISize;
numFanTris = desc.fIndexCount - 2;
} else {
numFanTris = desc.fVertexCount - 2;
// By forcing this to become indexed we are adding a constraint to the maximum
// number of vertices.
if (desc.fVertexCount > (SkTo<int>(UINT16_MAX) + 1)) {
sk_bzero(this, sizeof(*this));
return;
}
}
if (numFanTris <= 0) {
sk_bzero(this, sizeof(*this));
return;
}
fISize = safe.mul(numFanTris, 3 * sizeof(uint16_t));
}
fTotal = safe.add(sizeof(SkVertices),
safe.add(fVSize,
safe.add(fTSize,
safe.add(fCSize,
fISize))));
if (safe.ok()) {
fArrays = fVSize + fTSize + fCSize + fISize; // just the sum of the arrays
} else {
sk_bzero(this, sizeof(*this));
}
}
bool isValid() const { return fTotal != 0; }
size_t fTotal = 0; // size of entire SkVertices allocation (obj + arrays)
size_t fArrays; // size of all the data arrays (V + D + T + C + I)
size_t fVSize;
size_t fTSize;
size_t fCSize;
size_t fISize;
// For indexed tri-fans this is the number of amount of space fo indices needed in the builder
// before conversion to indexed triangles (or zero if not indexed or not a triangle fan).
size_t fBuilderTriFanISize;
};
SkVertices::Builder::Builder(VertexMode mode, int vertexCount, int indexCount,
uint32_t builderFlags) {
bool hasTexs = SkToBool(builderFlags & SkVertices::kHasTexCoords_BuilderFlag);
bool hasColors = SkToBool(builderFlags & SkVertices::kHasColors_BuilderFlag);
this->init({mode, vertexCount, indexCount, hasTexs, hasColors});
}
SkVertices::Builder::Builder(const Desc& desc) {
this->init(desc);
}
void SkVertices::Builder::init(const Desc& desc) {
Sizes sizes(desc);
if (!sizes.isValid()) {
SkASSERT(!this->isValid());
return;
}
void* storage = ::operator new (sizes.fTotal);
if (sizes.fBuilderTriFanISize) {
fIntermediateFanIndices.reset(new uint8_t[sizes.fBuilderTriFanISize]);
}
fVertices.reset(new (storage) SkVertices);
// need to point past the object to store the arrays
char* ptr = (char*)storage + sizeof(SkVertices);
// return the original ptr (or null), but then advance it by size
auto advance = [&ptr](size_t size) {
char* new_ptr = size ? ptr : nullptr;
ptr += size;
return new_ptr;
};
fVertices->fPositions = (SkPoint*) advance(sizes.fVSize);
fVertices->fTexs = (SkPoint*) advance(sizes.fTSize);
fVertices->fColors = (SkColor*) advance(sizes.fCSize);
fVertices->fIndices = (uint16_t*)advance(sizes.fISize);
fVertices->fVertexCount = desc.fVertexCount;
fVertices->fIndexCount = desc.fIndexCount;
fVertices->fMode = desc.fMode;
// We defer assigning fBounds and fUniqueID until detach() is called
}
sk_sp<SkVertices> SkVertices::Builder::detach() {
if (fVertices) {
fVertices->fBounds.setBounds(fVertices->fPositions, fVertices->fVertexCount);
if (fVertices->fMode == kTriangleFan_VertexMode) {
if (fIntermediateFanIndices) {
SkASSERT(fVertices->fIndexCount);
auto tempIndices = this->indices();
for (int t = 0; t < fVertices->fIndexCount - 2; ++t) {
fVertices->fIndices[3 * t + 0] = tempIndices[0];
fVertices->fIndices[3 * t + 1] = tempIndices[t + 1];
fVertices->fIndices[3 * t + 2] = tempIndices[t + 2];
}
fVertices->fIndexCount = 3 * (fVertices->fIndexCount - 2);
} else {
SkASSERT(!fVertices->fIndexCount);
for (int t = 0; t < fVertices->fVertexCount - 2; ++t) {
fVertices->fIndices[3 * t + 0] = 0;
fVertices->fIndices[3 * t + 1] = SkToU16(t + 1);
fVertices->fIndices[3 * t + 2] = SkToU16(t + 2);
}
fVertices->fIndexCount = 3 * (fVertices->fVertexCount - 2);
}
fVertices->fMode = kTriangles_VertexMode;
}
fVertices->fUniqueID = next_id();
return std::move(fVertices); // this will null fVertices after the return
}
return nullptr;
}
SkPoint* SkVertices::Builder::positions() {
return fVertices ? const_cast<SkPoint*>(fVertices->fPositions) : nullptr;
}
SkPoint* SkVertices::Builder::texCoords() {
return fVertices ? const_cast<SkPoint*>(fVertices->fTexs) : nullptr;
}
SkColor* SkVertices::Builder::colors() {
return fVertices ? const_cast<SkColor*>(fVertices->fColors) : nullptr;
}
uint16_t* SkVertices::Builder::indices() {
if (!fVertices) {
return nullptr;
}
if (fIntermediateFanIndices) {
return reinterpret_cast<uint16_t*>(fIntermediateFanIndices.get());
}
return const_cast<uint16_t*>(fVertices->fIndices);
}
///////////////////////////////////////////////////////////////////////////////////////////////////
sk_sp<SkVertices> SkVertices::MakeCopy(VertexMode mode, int vertexCount,
const SkPoint pos[], const SkPoint texs[],
const SkColor colors[],
int indexCount, const uint16_t indices[]) {
auto desc = Desc{mode, vertexCount, indexCount, !!texs, !!colors};
Builder builder(desc);
if (!builder.isValid()) {
return nullptr;
}
Sizes sizes(desc);
SkASSERT(sizes.isValid());
sk_careful_memcpy(builder.positions(), pos, sizes.fVSize);
sk_careful_memcpy(builder.texCoords(), texs, sizes.fTSize);
sk_careful_memcpy(builder.colors(), colors, sizes.fCSize);
size_t isize = (mode == kTriangleFan_VertexMode) ? sizes.fBuilderTriFanISize : sizes.fISize;
sk_careful_memcpy(builder.indices(), indices, isize);
return builder.detach();
}
size_t SkVertices::approximateSize() const {
return this->getSizes().fTotal;
}
SkVertices::Sizes SkVertices::getSizes() const {
Sizes sizes({fMode, fVertexCount, fIndexCount, !!fTexs, !!fColors});
SkASSERT(sizes.isValid());
return sizes;
}
///////////////////////////////////////////////////////////////////////////////////////////////////
// storage = packed | vertex_count | index_count | attr_count
// | pos[] | custom[] | texs[] | colors[] | indices[]
#define kMode_Mask 0x0FF
#define kHasTexs_Mask 0x100
#define kHasColors_Mask 0x200
void SkVerticesPriv::encode(SkWriteBuffer& buffer) const {
// packed has room for additional flags in the future
uint32_t packed = static_cast<uint32_t>(fVertices->fMode);
SkASSERT((packed & ~kMode_Mask) == 0); // our mode fits in the mask bits
if (fVertices->fTexs) {
packed |= kHasTexs_Mask;
}
if (fVertices->fColors) {
packed |= kHasColors_Mask;
}
SkVertices::Sizes sizes = fVertices->getSizes();
SkASSERT(!sizes.fBuilderTriFanISize);
// Header
buffer.writeUInt(packed);
buffer.writeInt(fVertices->fVertexCount);
buffer.writeInt(fVertices->fIndexCount);
// Data arrays
buffer.writeByteArray(fVertices->fPositions, sizes.fVSize);
buffer.writeByteArray(fVertices->fTexs, sizes.fTSize);
buffer.writeByteArray(fVertices->fColors, sizes.fCSize);
// if index-count is odd, we won't be 4-bytes aligned, so we call the pad version
buffer.writeByteArray(fVertices->fIndices, sizes.fISize);
}
sk_sp<SkVertices> SkVerticesPriv::Decode(SkReadBuffer& buffer) {
auto decode = [](SkReadBuffer& buffer) -> sk_sp<SkVertices> {
SkSafeRange safe;
bool hasCustomData = buffer.isVersionLT(SkPicturePriv::kVerticesRemoveCustomData_Version);
const uint32_t packed = buffer.readUInt();
const int vertexCount = safe.checkGE(buffer.readInt(), 0);
const int indexCount = safe.checkGE(buffer.readInt(), 0);
const int attrCount = hasCustomData ? safe.checkGE(buffer.readInt(), 0) : 0;
const SkVertices::VertexMode mode = safe.checkLE<SkVertices::VertexMode>(
packed & kMode_Mask, SkVertices::kLast_VertexMode);
const bool hasTexs = SkToBool(packed & kHasTexs_Mask);
const bool hasColors = SkToBool(packed & kHasColors_Mask);
// Check that the header fields and buffer are valid. If this is data with the experimental
// custom attributes feature - we don't support that any more.
// We also don't support serialized triangle-fan data. We stopped writing that long ago,
// so it should never appear in valid encoded data.
if (!safe || !buffer.isValid() || attrCount ||
mode == SkVertices::kTriangleFan_VertexMode) {
return nullptr;
}
const SkVertices::Desc desc{mode, vertexCount, indexCount, hasTexs, hasColors};
SkVertices::Sizes sizes(desc);
if (!sizes.isValid() || sizes.fArrays > buffer.available()) {
return nullptr;
}
SkVertices::Builder builder(desc);
if (!builder.isValid()) {
return nullptr;
}
buffer.readByteArray(builder.positions(), sizes.fVSize);
if (hasCustomData) {
size_t customDataSize = 0;
buffer.skipByteArray(&customDataSize);
if (customDataSize != 0) {
return nullptr;
}
}
buffer.readByteArray(builder.texCoords(), sizes.fTSize);
buffer.readByteArray(builder.colors(), sizes.fCSize);
buffer.readByteArray(builder.indices(), sizes.fISize);
if (!buffer.isValid()) {
return nullptr;
}
if (indexCount > 0) {
// validate that the indices are in range
const uint16_t* indices = builder.indices();
for (int i = 0; i < indexCount; ++i) {
if (indices[i] >= (unsigned)vertexCount) {
return nullptr;
}
}
}
return builder.detach();
};
if (auto verts = decode(buffer)) {
return verts;
}
buffer.validate(false);
return nullptr;
}
void SkVertices::operator delete(void* p) {
::operator delete(p);
}