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Load_IFF() parse RAST chunks

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Thomas Bernard 2018-02-22 23:59:46 +01:00
parent 2338e99d47
commit ca352e756c
1 changed files with 95 additions and 0 deletions
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95
src/fileformats.c
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@ -807,6 +807,68 @@ static void LBM_Decode(T_IO_Context * context, FILE * file, byte compression, by
}
}
static void RAST_chunk_decode(T_IO_Context * context, FILE * file, dword section_size, T_IFF_PCHG_Palette ** PCHG_palettes)
{
int i;
T_Components palette[16];
T_IFF_PCHG_Palette * prev_pal = NULL;
T_IFF_PCHG_Palette * new_pal = NULL;
// 17 words per palette : 1 for line, 16 for the colors
while (section_size >= 34)
{
word line, value;
Read_word_be(file, &line);
for (i = 0; i < 16; i++)
{
Read_word_be(file, &value); // Decode STE Palette
palette[i].R = ((value & 0x0700) >> 7 | (value & 0x0800) >> 11) * 0x11;
palette[i].G = ((value & 0x0070) >> 3 | (value & 0x0080) >> 7) * 0x11;
palette[i].B = ((value & 0x0007) << 1 | (value & 0x0008) >> 3) * 0x11;
}
section_size -= 34;
if (prev_pal == NULL || (line > prev_pal->StartLine && (0 != memcmp(palette, prev_pal->Palette, sizeof(T_Components)*3))))
{
new_pal = malloc(sizeof(T_IFF_PCHG_Palette) + sizeof(T_Components) * 16);
if (new_pal == NULL)
{
File_error = 2;
return;
}
memcpy(new_pal->Palette, palette, sizeof(T_Components) * 16);
new_pal->StartLine = line;
new_pal->Next = NULL;
if (prev_pal != NULL)
{
prev_pal->Next = new_pal;
prev_pal = new_pal;
}
else if (line == 0)
{
prev_pal = new_pal;
*PCHG_palettes = prev_pal;
}
else // line > 0 && prev_pal == NULL
{
// create a palette for line 0
prev_pal = malloc(sizeof(T_IFF_PCHG_Palette) + sizeof(T_Components) * 16);
if (prev_pal == NULL)
{
File_error = 2;
return;
}
memcpy(prev_pal->Palette, context->Palette, sizeof(T_Components) * 16);
prev_pal->StartLine = 0;
prev_pal->Next = new_pal;
*PCHG_palettes = prev_pal;
prev_pal = new_pal;
}
}
}
}
static void IFF_Set_EHB_Palette(T_IO_Context * context)
{
int i, j; // 32 colors in the palette.
@ -1759,6 +1821,17 @@ void Load_IFF(T_IO_Context * context)
if (PCHG_palettes != NULL)
bpp = 12;
}
else if (memcmp(section, "RAST", 4) == 0) // Atari ST
{
if (PCHG_palettes == NULL)
{
RAST_chunk_decode(context, IFF_file, section_size, &PCHG_palettes);
if (PCHG_palettes != NULL)
bpp = 12;
}
else
fseek(IFF_file, (section_size+1)&~1, SEEK_CUR); // Skip
}
else if (memcmp(section, "TINY", 4) == 0)
{
word tiny_width, tiny_height;
@ -1846,6 +1919,28 @@ void Load_IFF(T_IO_Context * context)
}
else if (memcmp(section, "BODY", 4) == 0)
{
long offset = ftell(IFF_file);
if (file_size > (offset + section_size + 8))
{
// Chunk RAST is placed AFTER the BODY, but we need the palette now to decode the image
// In addition, some files break the IFF standard by not aligning
// the chunk on word boundaries.
fseek(IFF_file, section_size, SEEK_CUR);
Read_bytes(IFF_file, section, 1);
if (section[0] == 'R') // we are good
Read_bytes(IFF_file, section + 1, 3); // read the remaining 3 bytes
else // skip 1 byte
Read_bytes(IFF_file, section, 4); // read 4 bytes
if (memcmp(section, "RAST", 4) == 0)
{
dword rast_size;
Read_dword_be(IFF_file, &rast_size);
RAST_chunk_decode(context, IFF_file, rast_size, &PCHG_palettes);
if (PCHG_palettes != NULL)
bpp = 12;
}
fseek(IFF_file, offset, SEEK_SET); // rewind
}
Original_screen_X = header.X_screen;
Original_screen_Y = header.Y_screen;