unsigned int CL_SoundProvider_Wave_Impl::find_subchunk(const char *chunk, CL_IODevice &source, unsigned int file_offset, unsigned int max_offset )
{
char subchunk1_id[4];
max_offset -= 8; // Each subchunk must contains at least name and size
while(file_offset < max_offset)
{
source.seek(file_offset);
source.read(subchunk1_id, 4);
cl_ubyte32 subchunk1_size = source.read_uint32();
if (!memcmp(subchunk1_id, chunk, 4))
{
// Found chunk
return subchunk1_size;
}
file_offset += subchunk1_size + 8;
}
throw CL_Exception("Block not found!");
}
void CL_PCXProvider_Impl::read_pcx(
CL_IODevice &_datafile)
{
// Read the file header and initialize the variables
// This method was created to breakup the PCX decoding code
// so the initializing code was separated from the actual
// decoding algorithm
unsigned char header[128];
{
int read = _datafile.read(header, 128);
if (read != 128)
throw CL_Exception("File not big enough to read the PCX header");
}
// only the useful fields that will be used more than once
struct PCXHeader {
unsigned char version;
unsigned char encoding;
unsigned char bits_per_pixel_per_plane;
short xmin;
short ymin;
short xmax;
short ymax;
unsigned char color_map[48];
unsigned char nplanes;
unsigned short bytes_per_line;
} pcx_header;
if (header[0] != 10)
throw CL_Exception("Not a PCX file");
pcx_header.version = header[1];
pcx_header.encoding = header[2];
pcx_header.bits_per_pixel_per_plane = header[3];
pcx_header.xmin = (header[5] << 8) | header[4];
pcx_header.ymin = (header[7] << 8) | header[6];
pcx_header.xmax = (header[9] << 8) | header[8];
pcx_header.ymax = (header[11] << 8) | header[10];
const int width = (pcx_header.xmax - pcx_header.xmin) + 1;
const int height = (pcx_header.ymax - pcx_header.ymin) + 1;
memcpy(pcx_header.color_map, &header[16], sizeof(pcx_header.color_map));
pcx_header.nplanes = header[65];
pcx_header.bytes_per_line = (header[67] << 8) | header[66];
// both 8bit with palette and 24bit rgb modes require version 5
if (pcx_header.version < 5)
throw CL_Exception("PCX version unsupported");
const int total_line_bytes = pcx_header.bytes_per_line * pcx_header.nplanes;
int pitch = 0;
// decide which pixelformat to use (8 bit palette or 24 bit)
if (pcx_header.nplanes == 3 && pcx_header.bits_per_pixel_per_plane == 8)
{
// 24 bit RGB mode
pitch = width * 3;
image = new unsigned char[pitch * height];
if (image == 0)
throw CL_Exception("Unable to allocate memory for pcx image");
unsigned char *p = image;
const int extra = total_line_bytes - pitch;
// get the data
if (!pcx_header.encoding)
{
// uncompressed
for (int y = 0; y < height; y++)
{
_datafile.read(p, pitch);
if (extra > 0)
_datafile.seek(extra, CL_IODevice::seek_cur);
p += pitch;
}
}
else
{
// compressed
for (int y = 0; y < height; y++)
{
int count;
// first red component
int x = 0, xx = 0, comp = 0;
while (x < total_line_bytes)
{
int ch = _datafile.read_uint8();
if ((ch & 0xC0) == 0xC0)
{
count = ch & 0x3F;
ch = _datafile.read_uint8();
}
else
count = 1;
while (count--)
{
if (xx < width)
image[(y * pitch) + ((xx * 3) + comp)] = ch;
x++;
if (x == pcx_header.bytes_per_line)
{
// blue component now
comp = 1;
xx = 0;
}
else if (x == pcx_header.bytes_per_line*2)
{
// green component now
comp = 2;
xx = 0;
}
else
xx++;
}
}
}
}
CL_PCXProvider_Impl::sized_format = cl_bgr8;
CL_PCXProvider_Impl::pitch = pitch;
CL_PCXProvider_Impl::width = width;
CL_PCXProvider_Impl::height = height;
}
else if (pcx_header.nplanes == 1 && pcx_header.bits_per_pixel_per_plane == 8)
{
// 8 bit indexed mode
pitch = width;
image = new unsigned char[pitch * height];
if (image == 0)
throw CL_Exception("Unable to allocate memory for pcx image");
unsigned char *p = image;
const int extra = total_line_bytes - pitch;
// get the data
if (!pcx_header.encoding)
{
// uncompressed
for (int y = 0; y < height; y++)
{
_datafile.read(p, pitch);
if (extra > 0)
_datafile.seek(extra, CL_IODevice::seek_cur);
p += pitch;
}
}
else
{
// compressed
for (int y = 0; y < height; y++)
{
int count;
int x = 0;
while (x < total_line_bytes)
{
int ch = _datafile.read_uint8();
if ((ch & 0xC0) == 0xC0)
{
count = ch & 0x3F;
ch = _datafile.read_uint8();
}
else
count = 1;
while (count--)
{
if (x < width)
{
*p = ch;
p++;
}
x++;
}
}
}
}
// read the palette
if (_datafile.read_int8() != 12)
{
delete[] image;
throw CL_Exception("Palette not found");
}
for (int i = 0; i < 256; i++)
{
const int r = _datafile.read_uint8();
const int g = _datafile.read_uint8();
const int b = _datafile.read_uint8();
palette[i].set_color(r, g, b);
}
CL_PCXProvider_Impl::sized_format = cl_color_index;
CL_PCXProvider_Impl::pitch = pitch;
CL_PCXProvider_Impl::width = width;
CL_PCXProvider_Impl::height = height;
}
else
throw CL_Exception("Unsupported PCX format");
}
