Pecus/libretro-atari800
1
0
Fork 0
mirror of https://github.com/Pecusx/libretro-atari800.git synced 2026-05-21 14:49:36 +02:00
Code Issues Packages Projects Releases Wiki Activity

initial commit

Browse Source
This commit is contained in:
R-type
2015-12-14 14:00:35 +01:00
commit 5a96c0ca66
377 changed files with 149124 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files
atari800/src/cycle_map.c
+201
View File
@@ -0,0 +1,201 @@
/*
* cycle_map.c - part of the ANTIC emulation
*
* Copyright (C) 1995-1998 Perry McFarlane
* Copyright (C) 1998-2005 Atari800 development team (see DOC/CREDITS)
*
* This file is part of the Atari800 emulator project which emulates
* the Atari 400, 800, 800XL, 130XE, and 5200 8-bit computers.
*
* Atari800 is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* Atari800 is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Atari800; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdio.h>
#include "cycle_map.h"
int CYCLE_MAP_cpu2antic[CYCLE_MAP_SIZE * (17 * 7 + 1)];
int CYCLE_MAP_antic2cpu[CYCLE_MAP_SIZE * (17 * 7 + 1)];
static void try_all_scroll(int md, int use_char_index,
int use_font, int use_bitmap, int *cpu2antic, int *antic2cpu);
static void antic_steal_map(int width, int md, int scroll_offset, int use_char_index,
int use_font, int use_bitmap, char *antic_cycles, int *cpucycles,
int *actualcycles);
static void cpu_cycle_map(char *antic_cycles_orig, int *cpu_cycles, int *actual_cycles);
#undef TEST_CYCLE_MAP
#ifdef TEST_CYCLE_MAP
int main()
{
CYCLE_MAP_Create();
return 0;
};
#endif
static void cpu_cycle_map(char *antic_cycles_orig, int *cpu_cycles, int *actual_cycles)
{
int i;
char antic_cycles[CYCLE_MAP_SIZE];
int antic_xpos;
int cpu_xpos = 0;
for (i = 0; i <= 113; i++)
antic_cycles[i] = antic_cycles_orig[i];
for (i = 114; i < CYCLE_MAP_SIZE; i++)
antic_cycles[i] = '.';
for (i = 0; i < CYCLE_MAP_SIZE; i++)
cpu_cycles[i]=-1;
for (antic_xpos = 0; antic_xpos < CYCLE_MAP_SIZE; antic_xpos++) {
char c = antic_cycles[antic_xpos];
actual_cycles[antic_xpos] = cpu_xpos;
if (c != 'R' && c != 'S' && c != 'F' && c != 'I') {
/*Not a stolen cycle*/
cpu_cycles[cpu_xpos] = antic_xpos;
cpu_xpos++;
}
}
}
void CYCLE_MAP_Create(void)
{
#ifdef TEST_CYCLE_MAP
int i, j;
int *cpu_cycles;
int *actual_cycles;
#endif
char antic_cycles[115];
int k = 0;
antic_steal_map(1, 0, 0, 0, 0, 0, antic_cycles, &CYCLE_MAP_cpu2antic[k], &CYCLE_MAP_antic2cpu[k]); /* blank line, or mode 8-F following line*/
k = CYCLE_MAP_SIZE * (17 * 0 + 1);
try_all_scroll(0, 1, 1, 0, &CYCLE_MAP_cpu2antic[k], &CYCLE_MAP_antic2cpu[k]); /* mode 2,3,4,5 first line */
k = CYCLE_MAP_SIZE * (17 * 1 + 1);
try_all_scroll(0, 0, 1, 0, &CYCLE_MAP_cpu2antic[k], &CYCLE_MAP_antic2cpu[k]); /* mode 2,3,4,5 following lines */
k = CYCLE_MAP_SIZE * (17 * 2 + 1);
try_all_scroll(1, 1, 1, 0, &CYCLE_MAP_cpu2antic[k], &CYCLE_MAP_antic2cpu[k]); /* mode 6,7 first line */
k = CYCLE_MAP_SIZE * (17 * 3 + 1);
try_all_scroll(1, 0, 1, 0, &CYCLE_MAP_cpu2antic[k], &CYCLE_MAP_antic2cpu[k]); /* mode 6,7 following lines */
k = CYCLE_MAP_SIZE * (17 * 4 + 1);
try_all_scroll(0, 0, 0, 1, &CYCLE_MAP_cpu2antic[k], &CYCLE_MAP_antic2cpu[k]); /* mode 8,9 first line */
k = CYCLE_MAP_SIZE * (17 * 5 + 1);
try_all_scroll(1, 0, 0, 1, &CYCLE_MAP_cpu2antic[k], &CYCLE_MAP_antic2cpu[k]); /* mode A,B,C first line */
k = CYCLE_MAP_SIZE * (17 * 6 + 1);
try_all_scroll(2, 0, 0, 1, &CYCLE_MAP_cpu2antic[k], &CYCLE_MAP_antic2cpu[k]); /* mode D,E,F first line */
#ifdef TEST_CYCLE_MAP
for(j = 0; j < 17 * 7 + 1; j++) {
cpu_cycles = &CYCLE_MAP_cpu2antic[CYCLE_MAP_SIZE * j];
actual_cycles = &CYCLE_MAP_antic2cpu[CYCLE_MAP_SIZE * j];
printf("%3d ", actual_cycles[114]);
for(i = 0; i <= actual_cycles[114] + 6; i++)
printf("%3d, ", cpu_cycles[i]);
printf("\n");
}
#endif
}
static void try_all_scroll(int md, int use_char_index,
int use_font, int use_bitmap, int *cpu2antic, int *antic2cpu)
{
char antic_cycles[115];
int width;
int scroll_offset = 0;
width = 1; /* narrow width without scroll*/
antic_steal_map(width, md, scroll_offset, use_char_index, use_font,
use_bitmap, antic_cycles, &cpu2antic[CYCLE_MAP_SIZE * 0], &antic2cpu[CYCLE_MAP_SIZE * 0]);
width = 2; /* standard without scroll or narrow with scroll */
for (scroll_offset = 0; scroll_offset <= 7; scroll_offset++) {
antic_steal_map(width, md, scroll_offset, use_char_index, use_font,
use_bitmap, antic_cycles, &cpu2antic[CYCLE_MAP_SIZE * (1 + scroll_offset)],
&antic2cpu[CYCLE_MAP_SIZE * (1 + scroll_offset)]);
}
width = 3; /* standard with scroll or wide */
for (scroll_offset = 0; scroll_offset <= 7; scroll_offset++) {
antic_steal_map(width, md, scroll_offset, use_char_index, use_font,
use_bitmap, antic_cycles, &cpu2antic[CYCLE_MAP_SIZE * (9 + scroll_offset)],
&antic2cpu[CYCLE_MAP_SIZE * (9 + scroll_offset)]);
}
}
static void antic_steal_map(int width, int md, int scroll_offset, int use_char_index,
int use_font, int use_bitmap, char *antic_cycles, int *cpu_cycles,
int *actual_cycles)
{
int char_start;
int bitmap_start;
int font_start;
int i;
int dram_pending;
int interval;
int steal;
int max_chars;
/* defaults for wide playfield */
#define CHAR_C 13
#define BITMAP_C (CHAR_C + 2)
#define FONT_C (CHAR_C + 3)
#define END_C (CHAR_C + 95)
#define DMARS_C (CHAR_C + 15)
#define DMARE_C (DMARS_C + 32)
char_start = CHAR_C + scroll_offset;
bitmap_start = BITMAP_C + scroll_offset;
font_start = FONT_C + scroll_offset;
max_chars = 48;
if (width == 2) { /* standard width */
char_start += 8;
bitmap_start += 8;
font_start += 8;
max_chars = 40;
}
else if (width == 1) { /* narrow */
char_start += 16;
bitmap_start += 16;
font_start += 16;
max_chars = 32;
}
interval = (2 << md);
max_chars = (max_chars >> md);
for (i = 0; i <= 113; i++)
antic_cycles[i] = '.';
antic_cycles[114] = '\0';
antic_cycles[0] = 'M';
antic_cycles[1] = antic_cycles[6] = antic_cycles[7] = 'D';
antic_cycles[2] = antic_cycles[3] = antic_cycles[4] = antic_cycles[5] = 'P';
dram_pending = 0;
for (i = 0; i <= 114; i++) {
steal = 0;
if (i <= END_C) {
if (use_char_index && i >= char_start && ((i - char_start) % interval == 0)
&& ((i - char_start) < max_chars * interval)) {
steal = 'I';
}
if (use_font && i >= font_start && ((i - font_start) % interval == 0)
&& ((i - font_start) < max_chars * interval)) {
steal = 'F';
}
if (use_bitmap && i >= bitmap_start && ((i - bitmap_start) % interval == 0)
&& ((i - bitmap_start) < max_chars * interval)) {
steal = 'S';
}
if (i >= DMARS_C && i <= DMARE_C && ((i - DMARS_C) % 4 == 0)) {
dram_pending = 1;
}
}
if (steal !=0 ) {
antic_cycles[i] = steal;
}
else if (dram_pending != 0){
antic_cycles[i] = 'R';
dram_pending = 0;
}
}
cpu_cycle_map(antic_cycles, cpu_cycles, actual_cycles);
}