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main.c
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main.c
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/******************************************************************************
GrooveStomp's NES Emulator
Copyright (c) 2019 Aaron Oman (GrooveStomp)
File: main.c
Created: 2019-10-31
Updated: 2019-12-06
Author: Aaron Oman
Notice: GNU AGPLv3 License
Based off of: One Lone Coder NES Emulator Copyright (C) 2019 Javidx9
This program comes with ABSOLUTELY NO WARRANTY.
This is free software, and you are welcome to redistribute it under certain
conditions; See LICENSE for details.
******************************************************************************/
//! \file main.c
#include <time.h> // struct timespec, clock_gettime
#include <stdlib.h> // strtoul, exit
#include <string.h> // strlen
#include <stdio.h> // printf
#include "bus.h"
#include "cart.h"
#include "color.h"
#include "cpu.h"
#include "graphics.h"
#include "input.h"
#include "ppu.h"
#include "util.h"
static const int FONT_HEADER_SCALE = 20;
static const int FONT_SCALE = 15;
static const int NES_SCREEN_WIDTH = 256 * 3;
static const int NES_SCREEN_HEIGHT = 240 * 3;
static const int WIDTH = NES_SCREEN_WIDTH + 250;
static const int HEIGHT = NES_SCREEN_HEIGHT;
static const int SWATCH_SIZE = 5;
static struct cpu *cpu = NULL;
static struct ppu *ppu = NULL;
static struct bus *bus = NULL;
static struct input *input = NULL;
static struct graphics *graphics = NULL;
static struct cart *cart = NULL;
static char *font_buffer = NULL;
void Deinit(int code) {
if (NULL != font_buffer)
free(font_buffer);
if (NULL != graphics)
GraphicsDeinit(graphics);
if (NULL != input)
InputDeinit(input);
if (NULL != ppu)
PpuDeinit(ppu);
if (NULL != bus)
BusDeinit(bus);
if (NULL != cpu)
CpuDeinit(cpu);
if (NULL != cart)
CartDeinit(cart);
exit(code);
}
void Init() {
char *ttf_filename = "/usr/share/fonts/truetype/ubuntu/UbuntuMono-R.ttf";
cart = CartInit("super_mario_bros.nes");
if (NULL == cart) {
fprintf(stderr, "Couldn't load cart");
Deinit(1);
}
if (!CartIsImageValid(cart)) {
fprintf(stderr, "Couldn't load cart");
Deinit(1);
}
cpu = CpuInit();
if (NULL == cpu) {
fprintf(stderr, "Couldn't initialize cpu");
Deinit(1);
}
ppu = PpuInit();
if (NULL == ppu) {
fprintf(stderr, "Couldn't initialize ppu");
Deinit(1);
}
bus = BusInit(cpu, ppu);
if (NULL == bus) {
fprintf(stderr, "Couldn't initialize bus");
Deinit(1);
}
input = InputInit();
if (NULL == input) {
fprintf(stderr, "Couldn't initialize input");
Deinit(1);
}
graphics = GraphicsInit("GrooveStomp's NES Emulator", WIDTH, HEIGHT);
if (NULL == graphics) {
fprintf(stderr, "Couldn't initialize graphics");
Deinit(1);
}
FILE *ttf_file = fopen(ttf_filename, "rb");
if (NULL == ttf_file) {
perror("fopen() failed");
fclose(ttf_file);
Deinit(1);
}
fseek(ttf_file, 0, SEEK_END);
size_t fsize = ftell(ttf_file);
font_buffer = (char *)malloc(fsize);
if (NULL == font_buffer) {
fprintf(stderr, "Couldn't allocate space for font buffer");
fclose(ttf_file);
Deinit(1);
}
fseek(ttf_file, 0, SEEK_SET);
size_t objsRead = fread(font_buffer, 1, fsize, ttf_file);
if (objsRead != 1 && ferror(ttf_file)) {
perror("fread() failed");
fclose(ttf_file);
Deinit(1);
}
fclose(ttf_file);
GraphicsInitText(graphics, (unsigned char *)font_buffer);
}
void DrawCpuState(int x, int y) {
GraphicsDrawText(graphics, x, y, "CPU State", FONT_HEADER_SCALE, 0x000000FF);
int numLines = 0;
char **cpuState = CpuDebugStateInit(cpu, &numLines);
for (int i = 0; i < numLines; i++) {
GraphicsDrawText(graphics, x, (y - 15) - (18 * i), cpuState[i], FONT_SCALE, 0x000000FF);
}
CpuDebugStateDeinit(cpuState);
}
void DrawDisassembly(struct disassembly *disassembly, int x, int y, int numLines) {
if (NULL == disassembly) return;
GraphicsDrawText(graphics, x, y, "Disassembly", FONT_HEADER_SCALE, 0x000000FF);
int pc = DisassemblyFindPc(disassembly, cpu);
int halfLines = (int)(0.5f * (float)numLines);
int min = pc - halfLines;
int max = pc + halfLines;
for (int i = min, si = 0; i < max; i++, si++) {
int yOff = (y - 25) - (18 * si);
if (i < 0 || i > 0xFFFF) {
GraphicsDrawLine(graphics, x, yOff + 5 , x + 230, yOff + 5, ColorRed.rgba);
} else if (NULL == disassembly->map || NULL == disassembly->map[i]) {
GraphicsDrawLine(graphics, x, yOff + 5 , x + 230, yOff + 5, ColorGray.rgba);
} else if (i == pc) {
GraphicsDrawText(graphics, x, yOff, disassembly->map[i]->text, FONT_SCALE, ColorBlue.rgba);
} else {
GraphicsDrawText(graphics, x, yOff, disassembly->map[i]->text, FONT_SCALE, ColorBlack.rgba);
}
}
}
int main(int argc, char **argv) {
Init();
CpuConnectBus(cpu, bus);
BusAttachCart(bus, cart);
BusReset(bus);
// Disassemble
struct disassembly *disassembly = DisassemblyInit(cpu, 0x0010, 0x0030);
struct timespec frameEnd;
struct timespec frameStart;
clock_gettime(CLOCK_REALTIME, &frameStart);
double residualTime = 0.0;
int isEmulating = 1;
int isRunning = 1;
int selectedPalette = 0;
while (isRunning) {
clock_gettime(CLOCK_REALTIME, &frameEnd);
double elapsedTime = S_AS_MS(frameEnd.tv_sec - frameStart.tv_sec);
elapsedTime += NS_AS_MS(frameEnd.tv_nsec - frameStart.tv_nsec);
GraphicsBegin(graphics);
GraphicsClearScreen(graphics, 0xFFFFFFFF);
InputProcess(input);
isRunning = !InputIsQuitRequested(input);
struct controller *controllers = BusGetControllers(bus);
controllers[0].input = 0x00;
controllers[0].input |= InputGetKey(input, KEY_X).held ? 0x80 : 0x00;
controllers[0].input |= InputGetKey(input, KEY_Z).held ? 0x40 : 0x00;
controllers[0].input |= InputGetKey(input, KEY_A).held ? 0x20 : 0x00;
controllers[0].input |= InputGetKey(input, KEY_S).held ? 0x10 : 0x00;
controllers[0].input |= InputGetKey(input, KEY_UP).held ? 0x08 : 0x00;
controllers[0].input |= InputGetKey(input, KEY_DOWN).held ? 0x04 : 0x00;
controllers[0].input |= InputGetKey(input, KEY_LEFT).held ? 0x02 : 0x00;
controllers[0].input |= InputGetKey(input, KEY_RIGHT).held ? 0x01 : 0x00;
if (InputGetKey(input, KEY_SPACE).pressed) isEmulating = !isEmulating;
if (InputGetKey(input, KEY_R).pressed) BusReset(bus);
if (InputGetKey(input, KEY_P).pressed) {
++selectedPalette;
selectedPalette &= 0x07;
}
if (isEmulating) {
if (0.0f <= residualTime) {
residualTime -= elapsedTime;
} else {
residualTime += (1.0 / 60.0) - elapsedTime;
do { BusTick(bus); } while (!PpuIsFrameComplete(ppu));
PpuResetFrameCompletion(ppu);
}
} else {
// Emulate code step-by-step.
if (InputGetKey(input, KEY_C).pressed) {
// Tick enough times to execute a whole CPU instruction.
do { BusTick(bus); } while (!CpuIsComplete(cpu));
// The CPU clock runs slower than system clock,
// so it may be incomplete for additional system
// clock cycles. Drain those out.
do { BusTick(bus); } while (CpuIsComplete(cpu));
}
// Emulate one whole frame.
if (InputGetKey(input, KEY_F).pressed) {
// Clock enough times to draw a single frame.
do { BusTick(bus); } while (!PpuIsFrameComplete(ppu));
// Use residual clock cycles to complete the
// current instruction.
do { BusTick(bus); } while (!CpuIsComplete(cpu));
// Reset frame completion flag.
PpuResetFrameCompletion(ppu);
}
}
GraphicsDrawLine(graphics, NES_SCREEN_WIDTH, 0, NES_SCREEN_WIDTH, HEIGHT, ColorBlack.rgba);
DrawCpuState(NES_SCREEN_WIDTH + 10, HEIGHT - (FONT_HEADER_SCALE + 5));
GraphicsDrawLine(graphics, NES_SCREEN_WIDTH, HEIGHT - 160, WIDTH, HEIGHT - 160, ColorBlack.rgba);
DrawDisassembly(disassembly, NES_SCREEN_WIDTH + 10, HEIGHT - 160 - (FONT_HEADER_SCALE + 5), 20);
// Iterate through each palette.
for (int p = 0; p < 8; p++)
for (int s = 0; s < 4; s++) {
struct color *color = PpuGetColorFromPaletteRam(ppu, p, s);
int x = NES_SCREEN_WIDTH + 1 + (p * 5 * (SWATCH_SIZE + 1)) + (s * (SWATCH_SIZE + 1));
int y = NES_SCREEN_HEIGHT - 590;
GraphicsDrawFilledRect(graphics, x, y, SWATCH_SIZE, SWATCH_SIZE, color->rgba);
}
// Draw selection reticule around selected palette.
GraphicsDrawRect(graphics, NES_SCREEN_WIDTH + (selectedPalette * 5 * (SWATCH_SIZE + 1)), NES_SCREEN_HEIGHT - 591, SWATCH_SIZE * 4 + 4, SWATCH_SIZE + 1, ColorBlack.rgba);
// Draw the pattern tables.
GraphicsDrawSprite(graphics, NES_SCREEN_WIDTH, HEIGHT - 719, PpuGetPatternTable(ppu, 0, selectedPalette), 1);
GraphicsDrawSprite(graphics, NES_SCREEN_WIDTH + 129, HEIGHT - 719, PpuGetPatternTable(ppu, 1, selectedPalette), 1);
GraphicsDrawSprite(graphics, 0, 0, PpuScreen(ppu), 3);
GraphicsEnd(graphics);
}
DisassemblyDeinit(disassembly);
// Reset
BusReset(bus);
Deinit(0);
return 0;
}