skia2/include/core/SkWriter32.h
reed@google.com 5b3d5349be add helper available()
git-svn-id: http://skia.googlecode.com/svn/trunk@1188 2bbb7eff-a529-9590-31e7-b0007b416f81
2011-04-26 17:49:03 +00:00

121 lines
3.3 KiB
C++

/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef SkWriter32_DEFINED
#define SkWriter32_DEFINED
#include "SkTypes.h"
#include "SkScalar.h"
#include "SkPoint.h"
#include "SkRect.h"
class SkStream;
class SkWStream;
class SkWriter32 : SkNoncopyable {
public:
SkWriter32(size_t minSize) {
fMinSize = minSize;
fSize = 0;
fHead = fTail = NULL;
}
~SkWriter32();
bool writeBool(bool value) {
this->writeInt(value);
return value;
}
void writeInt(int32_t value) {
*(int32_t*)this->reserve(sizeof(value)) = value;
}
void write8(int32_t value) {
*(int32_t*)this->reserve(sizeof(value)) = value & 0xFF;
}
void write16(int32_t value) {
*(int32_t*)this->reserve(sizeof(value)) = value & 0xFFFF;
}
void write32(int32_t value) {
*(int32_t*)this->reserve(sizeof(value)) = value;
}
void writeScalar(SkScalar value) {
*(SkScalar*)this->reserve(sizeof(value)) = value;
}
void writePoint(const SkPoint& pt) {
*(SkPoint*)this->reserve(sizeof(pt)) = pt;
}
void writeRect(const SkRect& rect) {
*(SkRect*)this->reserve(sizeof(rect)) = rect;
}
// write count bytes (must be a multiple of 4)
void writeMul4(const void* values, size_t size) {
this->write(values, size);
}
/**
* Write size bytes from values. size must be a multiple of 4, though
* values need not be 4-byte aligned.
*/
void write(const void* values, size_t size) {
SkASSERT(SkAlign4(size) == size);
// if we could query how much is avail in the current block, we might
// copy that much, and then alloc the rest. That would reduce the waste
// in the current block
memcpy(this->reserve(size), values, size);
}
void writePad(const void* src, size_t size);
// return the current offset (will always be a multiple of 4)
uint32_t size() const { return fSize; }
void reset();
uint32_t* reserve(size_t size); // size MUST be multiple of 4
// return the address of the 4byte int at the specified offset (which must
// be a multiple of 4. This does not allocate any new space, so the returned
// address is only valid for 1 int.
uint32_t* peek32(size_t offset);
// copy into a single buffer (allocated by caller). Must be at least size()
void flatten(void* dst) const;
// read from the stream, and write up to length bytes. Return the actual
// number of bytes written.
size_t readFromStream(SkStream*, size_t length);
bool writeToStream(SkWStream*);
private:
size_t fMinSize;
uint32_t fSize;
struct Block;
Block* fHead;
Block* fTail;
Block* newBlock(size_t bytes);
};
#endif