ys2-intro/loader/tools/exomizer-3.1/src/desfx.c
2025-11-13 19:07:39 +03:00

103 lines
2.5 KiB
C

/*
* Copyright (c) 2007 - 2018 Magnus Lind.
*
* This software is provided 'as-is', without any express or implied warranty.
* In no event will the authors be held liable for any damages arising from
* the use of this software.
*
* Permission is granted to anyone to use this software, alter it and re-
* distribute it freely for any non-commercial, non-profit purpose subject to
* the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software in a
* product, an acknowledgment in the product documentation would be
* appreciated but is not required.
*
* 2. Altered source versions must be plainly marked as such, and must not
* be misrepresented as being the original software.
*
* 3. This notice may not be removed or altered from any distribution.
*
* 4. The names of this software and/or it's copyright holders may not be
* used to endorse or promote products derived from this software without
* specific prior written permission.
*
*/
#include "desfx.h"
#include "6502emu.h"
#include "log.h"
#include "vec.h"
#include "areatrace.h"
struct mem_ctx
{
u8 *mem;
struct areatrace at;
};
static void mem_access_write(struct mem_access *this, u16 address, u8 value)
{
struct mem_ctx *ctx = this->ctx;
if ((ctx->mem[1] & 4) == 4 && (ctx->mem[1] & 3) != 0 &&
address >= 0xd000 && address < 0xe000)
{
/* IO-area written and visible */
return;
}
ctx->mem[address] = value;
areatrace_access(&ctx->at, address);
}
static u8 mem_access_read(struct mem_access *this, u16 address)
{
struct mem_ctx *ctx = this->ctx;
return ctx->mem[address];
}
u16 decrunch_sfx(u8 mem[65536], u16 run, int *startp, int *endp, u32 *cyclesp)
{
struct mem_ctx m;
struct cpu_ctx r;
r.cycles = 0;
r.mem.ctx = &m;
r.mem.read = mem_access_read;
r.mem.write = mem_access_write;
r.pc = run;
r.sp = '\xf6';
r.flags = 0;
m.mem = mem;
m.mem[1] = 0x37;
areatrace_init(&m.at);
LOG(LOG_DEBUG, ("run %04x\n", run));
/* setting up decrunch */
while(r.pc >= 0x0400 || r.sp != 0xf6)
{
next_inst(&r);
}
/* decrunching */
while(r.pc < 0x400)
{
next_inst(&r);
}
areatrace_merge_overlapping(&m.at);
areatrace_get_largest(&m.at, startp, endp);
if(cyclesp != NULL)
{
*cyclesp = r.cycles;
}
areatrace_free(&m.at);
return r.pc;
}