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use PackBits for saving .PRG

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Thomas Bernard 2020-01-01 23:54:59 +01:00
parent 59b029effe
commit c820ba61ac
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GPG Key ID: 0FF11B67A5C0863C
1 changed files with 43 additions and 9 deletions
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44
src/c64formats.c
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@ -42,6 +42,7 @@
#include "oldies.h"
#include "c64load.h"
#include "keycodes.h"
#include "packbits.h"
#include "gfx2mem.h"
#include "gfx2log.h"
@ -1655,11 +1656,14 @@ void Save_C64(T_IO_Context * context)
*
* The output format is a stream of bytes of the following format :
* CD C = (16 - count), D = DATA (4bits)
*
* @return the output stream size, -1 for error
*/
static int C64_color_ram_pack(FILE * f, const byte * data, int count)
{
byte previous = 0;
int repeat_count = 0;
int output_count = 0;
while (count-- > 0)
{
if (repeat_count == 0)
@ -1674,6 +1678,7 @@ static int C64_color_ram_pack(FILE * f, const byte * data, int count)
{
if (!Write_byte(f, previous))
return 0;
output_count++;
repeat_count = 0;
}
}
@ -1681,6 +1686,7 @@ static int C64_color_ram_pack(FILE * f, const byte * data, int count)
{
if (!Write_byte(f, ((16 - repeat_count) << 4) | previous))
return 0;
output_count++;
previous = *data & 0x0f;
repeat_count = 1;
}
@ -1689,9 +1695,10 @@ static int C64_color_ram_pack(FILE * f, const byte * data, int count)
if (repeat_count > 0)
{
if (!Write_byte(f, ((16 - repeat_count) << 4) | previous))
return 0;
return -1;
output_count++;
}
return 1;
return output_count;
}
/**
@ -1701,7 +1708,6 @@ static int C64_color_ram_pack(FILE * f, const byte * data, int count)
*/
void Save_PRG(T_IO_Context * context)
{
FILE *file;
byte background = 0;
byte bitmap[8000], screen_ram[1000], color_ram[1000];
enum c64_format saveFormat = F_invalid;
@ -1719,6 +1725,9 @@ void Save_PRG(T_IO_Context * context)
File_error = Encode_C64_multicolor(context, bitmap, screen_ram, color_ram, &background);
if (File_error == 0)
{
FILE *file;
int n;
file = Open_file_write(context);
if (file == NULL)
{
@ -1728,15 +1737,40 @@ void Save_PRG(T_IO_Context * context)
if (!Write_bytes(file, picview_prg, sizeof(picview_prg)))
File_error = 2;
Write_byte(file, 0x30); // Mode : Bitmap + Multicolor
// TODO : use packbits
n = PackBits_pack_buffer(NULL, bitmap, 8000);
GFX2_Log(GFX2_DEBUG, "PackBits of bitmap : 8000 => %d bytes\n", n + 1);
if (n >= 0 && n < 7999)
{
Write_byte(file, 0x11); // bitmap / packbits
PackBits_pack_buffer(file, bitmap, 8000);
Write_byte(file, 0x80); // end of packbits stream marker
}
else
{
// packing was not efficient
Write_byte(file, 0x10); // bitmap / no packing
Write_bytes(file, bitmap, 8000);
}
n = PackBits_pack_buffer(NULL, screen_ram, 1000);
GFX2_Log(GFX2_DEBUG, "PackBits of screen RAM : 1000 => %d bytes\n", n + 1);
if (n >= 0 && n < 999)
{
Write_byte(file, 0x21); // screen RAM / packbits
PackBits_pack_buffer(file, screen_ram, 1000);
Write_byte(file, 0x80); // end of packbits stream marker
}
else
{
Write_byte(file, 0x20); // screen RAM / no packing
Write_bytes(file, screen_ram, 1000);
}
//Write_byte(file, 0x30); // color RAM / no packing
//Write_bytes(file, color_ram, 1000);
Write_byte(file, 0x32); // color RAM / special color RAM packing
C64_color_ram_pack(file, color_ram, 1000);
n = C64_color_ram_pack(file, color_ram, 1000);
if (n < 0)
File_error = 1;
GFX2_Log(GFX2_DEBUG, "custom packing of color RAM : 1000 => %d bytes\n", n);
Write_byte(file, 0x42); // border/background/etc. / color ram RLE packing
Write_byte(file, background | 0x10);
Write_byte(file, 0); // end of file