// 写入一个字符到 buffer
void
writeToBuffer(unsigned char ch)
{
buffer[bufferpos] = ch;
bufferpos++;
if (bufferpos == BUFFERSIZE) // 缓冲区满了
{
commitBuffer(BUFFERSIZE);
bufferpos = 0;
}
}
Variable blendExpression::evaluate()
{
ImageObject* bottom = store->getImage();
Variable topVar = arguments[0]->getResult();
ImageObject* top = topVar.get<ImageObject>();
setLocalVariable("x", &x);
setLocalVariable("y", &y);
setLocalVariable("r1", &r1);
setLocalVariable("g1", &g1);
setLocalVariable("b1", &b1);
setLocalVariable("h1", &h1);
setLocalVariable("s1", &s1);
setLocalVariable("v1", &v1);
setLocalVariable("a1", &a1);
setLocalVariable("r2", &r2);
setLocalVariable("g2", &g2);
setLocalVariable("b2", &b2);
setLocalVariable("h2", &h2);
setLocalVariable("s2", &s2);
setLocalVariable("v2", &v2);
setLocalVariable("a2", &a2);
for (int cx = 0; cx < std::min(top->getWidth(),bottom->getWidth()); cx++)
for (int cy = 0; cy < std::min(top->getHeight(), bottom->getHeight()); cy++)
{
x = cx;
y = cy;
if (store->mask->getValue(cx, cy) > 0)
{
Colour b = bottom->getPixel(cx, cy);
r1 = (float)b.r();
g1 = (float)b.g();
b1 = (float)b.b();
h1 = (float)b.h();
s1 = (float)b.s();
v1 = (float)b.v();
a1 = (float)b.a();
Colour t = top->getPixel(cx, cy);
r2 = (float)t.r();
g2 = (float)t.g();
b2 = (float)t.b();
h2 = (float)t.h();
s2 = (float)t.s();
v2 = (float)t.v();
a2 = (float)t.a();
Variable col = arguments[1]->getResult();
buffer->setPixel(cx, cy, *col.get<Colour>());
}
}
commitBuffer();
return Variable();
}
void ViewBackend::handleMessage(char* data, size_t size)
{
if (size != IPC::Message::size)
return;
auto& message = IPC::Message::cast(data);
switch (message.messageCode) {
case IPC::BCMRPi::BufferCommit::code:
{
auto& bufferCommit = IPC::BCMRPi::BufferCommit::cast(message);
commitBuffer(bufferCommit.handle, bufferCommit.width, bufferCommit.height);
break;
}
default:
fprintf(stderr, "ViewBackend: unhandled message\n");
}
}
int
main(int argc, char ** argv)
{
if (argc != 4) // 检查参数数量
{
showUsage();
return 1;
}
else
{
filename = argv[1];
// 判断文件名的后缀是不是 ".hfm"
if (string(".hfm") != filename.substr(filename.length()-4, 4))
{
fprintf(stderr, "输入文件的后缀不是 .hfm 。\n");
return 1;
}
treeFilename = argv[2];
sscanf(argv[3], "%lu", &bitLength);
}
// 载入哈夫曼树
HuffmanTree tree;
tree.loadFromFile(treeFilename.c_str());
// 构造映射表
// 映射表是将字符映射到一个二进制序列的表
constructMapping(&tree, vector<int>());
// 打开待解码的文件
iBitFile bin((filename).c_str());
// 打开输出的文件
// file 定义在了本文件头部，为了方便函数 commitBuffer 而调整。
file = fopen((filename.substr(0, filename.length()-4)).c_str(), "wb");
// 解码
HuffmanTree * p = &tree;
for (size_t i=0; i<bitLength; ++i)
{
int bit = bin.readNextBit();
p = p->childs[bit];
if (p == NULL)
{
fprintf(stderr, "待解码文件和树文件似乎不是对应的。");
return 1;
}
if (p->key != -1)
{
writeToBuffer((unsigned char)p->key);
p = &tree;
}
}
commitBuffer(bufferpos);
fclose(file);
bin.close();
fflush(stdout);
return 0;
}
