ref: 7f02a74717a95e830b84e523a8ab1a275701403e
dir: /main.c/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <stdbool.h>
#include <SDL.h>
#ifdef _WIN32
#include <direct.h>
#else
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#endif
#include <math.h>
#include "snes/snes.h"
#include "tracing.h"
#include "types.h"
#include "variables.h"
#include "zelda_rtl.h"
#include "config.h"
extern Dsp *GetDspForRendering();
extern Snes *g_snes;
extern uint8 g_emulated_ram[0x20000];
void PatchRom(uint8 *rom);
void SetSnes(Snes *snes);
void RunAudioPlayer();
void CopyStateAfterSnapshotRestore(bool is_reset);
void SaveLoadSlot(int cmd, int which);
void PatchCommand(char cmd);
bool RunOneFrame(Snes *snes, int input_state, bool turbo);
static bool LoadRom(const char *name, Snes *snes);
static void PlayAudio(Snes *snes, SDL_AudioDeviceID device, int channels, int16 *audioBuffer);
static void RenderScreen(SDL_Window *window, SDL_Renderer *renderer, SDL_Texture *texture, bool fullscreen);
static void HandleInput(int keyCode, int modCode, bool pressed);
static void HandleGamepadInput(int button, bool pressed);
static void HandleGamepadAxisInput(int gamepad_id, int axis, int value);
static void OpenOneGamepad(int i);
enum {
kDefaultFullscreen = 0,
kDefaultWindowScale = 2,
kMaxWindowScale = 10,
kDefaultFreq = 44100,
kDefaultChannels = 2,
kDefaultSamples = 2048,
};
static const char kWindowTitle[] = "The Legend of Zelda: A Link to the Past";
static uint32 g_win_flags = SDL_WINDOW_RESIZABLE;
static SDL_Window *g_window;
static SDL_Renderer *g_renderer;
static uint8 g_paused, g_turbo = true, g_cursor = true;
static uint8 g_current_window_scale;
static int g_samples_per_block;
static uint8 g_gamepad_buttons;
static int g_input1_state;
static bool g_display_perf;
static int g_curr_fps;
static int g_ppu_render_flags = 0;
static bool g_run_without_emu = false;
static int g_snes_width, g_snes_height;
void NORETURN Die(const char *error) {
fprintf(stderr, "Error: %s\n", error);
exit(1);
}
void SetButtonState(int button, bool pressed) {
// set key in constroller
if (pressed) {
g_input1_state |= 1 << button;
} else {
g_input1_state &= ~(1 << button);
}
}
void ChangeWindowScale(int scale_step) {
int screen = SDL_GetWindowDisplayIndex(g_window);
if (screen < 0) screen = 0;
int max_scale = kMaxWindowScale;
SDL_Rect bounds;
int bt = -1, bl, bb, br;
// note this takes into effect Windows display scaling, i.e., resolution is divided by scale factor
if (SDL_GetDisplayUsableBounds(screen, &bounds) == 0) {
// this call may take a while before it is reported by Windows (or not at all in my testing)
if (SDL_GetWindowBordersSize(g_window, &bt, &bl, &bb, &br) != 0) {
// guess based on Windows 10/11 defaults
bl = br = bb = 1;
bt = 31;
}
// Allow a scale level slightly above the max that fits on screen
int mw = (bounds.w - bl - br + (g_snes_width / kDefaultWindowScale) / 4) / (g_snes_width / kDefaultWindowScale);
int mh = (bounds.h - bt - bb + (g_snes_height / kDefaultWindowScale) / 4) / (g_snes_height / kDefaultWindowScale);
max_scale = IntMin(mw, mh);
}
int new_scale = IntMax(IntMin(g_current_window_scale + scale_step, max_scale), 1);
g_current_window_scale = new_scale;
int w = new_scale * (g_snes_width / kDefaultWindowScale);
int h = new_scale * (g_snes_height / kDefaultWindowScale);
//SDL_RenderSetLogicalSize(g_renderer, w, h);
SDL_SetWindowSize(g_window, w, h);
if (bt >= 0) {
// Center the window on top of the mouse
int mx, my;
SDL_GetGlobalMouseState(&mx, &my);
int wx = IntMax(IntMin(mx - w / 2, bounds.x + bounds.w - bl - br - w), bounds.x + bl);
int wy = IntMax(IntMin(my - h / 2, bounds.y + bounds.h - bt - bb - h), bounds.y + bt);
SDL_SetWindowPosition(g_window, wx, wy);
} else {
SDL_SetWindowPosition(g_window, SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED);
}
}
static SDL_HitTestResult HitTestCallback(SDL_Window *win, const SDL_Point *area, void *data) {
uint32 flags = SDL_GetWindowFlags(win);
return ((flags & SDL_WINDOW_FULLSCREEN_DESKTOP) == 0 || (flags & SDL_WINDOW_FULLSCREEN) == 0) &&
(SDL_GetModState() & KMOD_CTRL) != 0 ? SDL_HITTEST_DRAGGABLE : SDL_HITTEST_NORMAL;
}
static bool RenderScreenWithPerf(uint8 *pixel_buffer, size_t pitch, uint32 render_flags) {
bool rv;
if (g_display_perf || g_config.display_perf_title) {
static float history[64], average;
static int history_pos;
uint64 before = SDL_GetPerformanceCounter();
rv = ZeldaDrawPpuFrame(pixel_buffer, pitch, render_flags);
uint64 after = SDL_GetPerformanceCounter();
float v = (double)SDL_GetPerformanceFrequency() / (after - before);
average += v - history[history_pos];
history[history_pos] = v;
history_pos = (history_pos + 1) & 63;
g_curr_fps = average * (1.0f / 64);
} else {
rv = ZeldaDrawPpuFrame(pixel_buffer, pitch, render_flags);
}
return rv;
}
// Go some steps up and find zelda3.ini
static void SwitchDirectory() {
char buf[4096];
if (!getcwd(buf, sizeof(buf) - 32))
return;
size_t pos = strlen(buf);
for (int step = 0; pos != 0 && step < 3; step++) {
memcpy(buf + pos, "/zelda3.ini", 12);
FILE *f = fopen(buf, "rb");
if (f) {
fclose(f);
buf[pos] = 0;
if (step != 0) {
printf("Found zelda3.ini in %s\n", buf);
chdir(buf);
}
return;
}
pos--;
while (pos != 0 && buf[pos] != '/' && buf[pos] != '\\')
pos--;
}
}
#undef main
int main(int argc, char** argv) {
SwitchDirectory();
ParseConfigFile();
AfterConfigParse();
ZeldaInitialize();
g_zenv.ppu->extraLeftRight = UintMin(g_config.extended_aspect_ratio, kPpuExtraLeftRight);
g_snes_width = 2 * (g_config.extended_aspect_ratio * 2 + 256);
g_snes_height = (g_config.extend_y ? 240 : 224) * 2;
// Delay actually setting those features in ram until any snapshots finish playing.
{
uint32 f = 0;
f |= (g_zenv.ppu->extraLeftRight && !g_config.extended_aspect_ratio_nospr) ? kFeatures0_ExtendScreen64 : 0;
f |= g_config.item_switch_lr * kFeatures0_SwitchLR;
f |= g_config.turn_while_dashing * kFeatures0_TurnWhileDashing;
f |= g_config.mirror_to_darkworld * kFeatures0_MirrorToDarkworld;
f |= g_config.collect_items_with_sword * kFeatures0_CollectItemsWithSword;
f |= g_config.break_pots_with_sword * kFeatures0_BreakPotsWithSword;
f |= g_config.disable_low_health_beep * kFeatures0_DisableLowHealthBeep;
g_wanted_zelda_features = f;
}
g_ppu_render_flags = g_config.new_renderer * kPpuRenderFlags_NewRenderer |
g_config.enhanced_mode7 * kPpuRenderFlags_4x4Mode7 |
g_config.extend_y * kPpuRenderFlags_Height240;
msu_enabled = g_config.enable_msu;
if (g_config.fullscreen == 1)
g_win_flags ^= SDL_WINDOW_FULLSCREEN_DESKTOP;
else if (g_config.fullscreen == 2)
g_win_flags ^= SDL_WINDOW_FULLSCREEN;
// Window scale (1=100%, 2=200%, 3=300%, etc.)
g_current_window_scale = (g_config.window_scale == 0) ? 2 : IntMin(g_config.window_scale, kMaxWindowScale);
// audio_freq: Use common sampling rates (see user config file. values higher than 48000 are not supported.)
if (g_config.audio_freq < 11025 || g_config.audio_freq > 48000)
g_config.audio_freq = kDefaultFreq;
// Currently, the SPC/DSP implementation �only supports up to stereo.
if (g_config.audio_channels < 1 || g_config.audio_channels > 2)
g_config.audio_channels = kDefaultChannels;
// audio_samples: power of 2
if (g_config.audio_samples <= 0 || ((g_config.audio_samples & (g_config.audio_samples - 1)) != 0))
g_config.audio_samples = kDefaultSamples;
// set up SDL
if(SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_GAMECONTROLLER) != 0) {
printf("Failed to init SDL: %s\n", SDL_GetError());
return 1;
}
int window_width = g_current_window_scale * (g_snes_width / kDefaultWindowScale);
int window_height = g_current_window_scale * (g_snes_height / kDefaultWindowScale);
SDL_Window* window = SDL_CreateWindow(kWindowTitle, SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, window_width, window_height, g_win_flags);
if(window == NULL) {
printf("Failed to create window: %s\n", SDL_GetError());
return 1;
}
g_window = window;
SDL_SetWindowHitTest(window, HitTestCallback, NULL);
SDL_Renderer* renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);
if(renderer == NULL) {
printf("Failed to create renderer: %s\n", SDL_GetError());
return 1;
}
SDL_RendererInfo renderer_info;
SDL_GetRendererInfo(renderer, &renderer_info);
printf("Supported texture formats:");
for (int i = 0; i < renderer_info.num_texture_formats; i++)
printf(" %s", SDL_GetPixelFormatName(renderer_info.texture_formats[i]));
printf("\n");
g_renderer = renderer;
if (!g_config.ignore_aspect_ratio)
SDL_RenderSetLogicalSize(renderer, g_snes_width, g_snes_height);
SDL_Texture* texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_STREAMING, g_snes_width * 2, g_snes_height * 2);
if(texture == NULL) {
printf("Failed to create texture: %s\n", SDL_GetError());
return 1;
}
SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "best");
SDL_AudioDeviceID device;
SDL_AudioSpec want = { 0 }, have;
int16_t* audioBuffer = NULL;
if (g_config.enable_audio) {
want.freq = g_config.audio_freq;
want.format = AUDIO_S16;
want.channels = g_config.audio_channels;
want.samples = g_config.audio_samples;
device = SDL_OpenAudioDevice(NULL, 0, &want, &have, 0);
if (device == 0) {
printf("Failed to open audio device: %s\n", SDL_GetError());
return 1;
}
g_samples_per_block = (534 * have.freq) / 32000;
audioBuffer = (int16_t*)malloc(g_samples_per_block * have.channels * sizeof(int16));
SDL_PauseAudioDevice(device, 0);
}
Snes *snes = snes_init(g_emulated_ram), *snes_run = NULL;
if (argc >= 2 && !g_run_without_emu) {
// init snes, load rom
bool loaded = LoadRom(argv[1], snes);
if (!loaded) {
puts("No rom loaded");
return 1;
}
snes_run = snes;
} else {
snes_reset(snes, true);
}
#if defined(_WIN32)
_mkdir("saves");
#else
mkdir("saves", 0755);
#endif
SetSnes(snes);
ZeldaReadSram(snes);
for (int i = 0; i < SDL_NumJoysticks(); i++)
OpenOneGamepad(i);
bool running = true;
SDL_Event event;
uint32 lastTick = SDL_GetTicks();
uint32 curTick = 0;
uint32 frameCtr = 0;
if (g_config.autosave)
SaveLoadSlot(kSaveLoad_Load, 0);
while(running) {
while(SDL_PollEvent(&event)) {
switch(event.type) {
case SDL_CONTROLLERDEVICEADDED:
OpenOneGamepad(event.cdevice.which);
break;
case SDL_CONTROLLERAXISMOTION:
HandleGamepadAxisInput(event.caxis.which, event.caxis.axis, event.caxis.value);
break;
case SDL_CONTROLLERBUTTONDOWN:
HandleGamepadInput(event.cbutton.button, event.cbutton.state == SDL_PRESSED);
break;
case SDL_CONTROLLERBUTTONUP:
HandleGamepadInput(event.cbutton.button, event.cbutton.state == SDL_PRESSED);
break;
case SDL_MOUSEWHEEL:
if (((g_win_flags & SDL_WINDOW_FULLSCREEN_DESKTOP) == 0 || (g_win_flags & SDL_WINDOW_FULLSCREEN) == 0) && event.wheel.y != 0 && SDL_GetModState() & KMOD_CTRL)
ChangeWindowScale(event.wheel.y > 0 ? 1 : -1);
break;
case SDL_MOUSEBUTTONDOWN:
if (event.button.button == SDL_BUTTON_LEFT && event.button.state == SDL_PRESSED && event.button.clicks == 2) {
if (((g_win_flags & SDL_WINDOW_FULLSCREEN_DESKTOP) == 0 || (g_win_flags & SDL_WINDOW_FULLSCREEN) == 0) && SDL_GetModState() & KMOD_SHIFT) {
g_win_flags ^= SDL_WINDOW_BORDERLESS;
SDL_SetWindowBordered(g_window, (g_win_flags & SDL_WINDOW_BORDERLESS) == 0);
}
}
break;
case SDL_KEYDOWN:
HandleInput(event.key.keysym.sym, event.key.keysym.mod, true);
break;
case SDL_KEYUP:
HandleInput(event.key.keysym.sym, event.key.keysym.mod, false);
break;
case SDL_QUIT:
running = false;
break;
}
}
if (g_paused) {
SDL_Delay(16);
continue;
}
// Clear gamepad inputs when joypad directional inputs to avoid wonkiness
int inputs = g_input1_state;
if (g_input1_state & 0xf0)
g_gamepad_buttons = 0;
uint64 t0 = SDL_GetPerformanceCounter();
bool is_turbo = RunOneFrame(snes_run, g_input1_state | g_gamepad_buttons, (frameCtr++ & 0x7f) != 0 && g_turbo);
if (is_turbo)
continue;
uint64 t1 = SDL_GetPerformanceCounter();
if (audioBuffer)
PlayAudio(snes_run, device, have.channels, audioBuffer);
uint64 t2 = SDL_GetPerformanceCounter();
RenderScreen(window, renderer, texture, (g_win_flags & SDL_WINDOW_FULLSCREEN_DESKTOP) != 0);
uint64 t3 = SDL_GetPerformanceCounter();
SDL_RenderPresent(renderer); // vsyncs to 60 FPS?
uint64 t4 = SDL_GetPerformanceCounter();
double f = 1e3 / (double)SDL_GetPerformanceFrequency();
if (0) printf("Perf %6.2f %6.2f %6.2f %6.2f\n",
(t1 - t0) * f,
(t2 - t1) * f,
(t3 - t2) * f,
(t4 - t3) * f
);
// if vsync isn't working, delay manually
curTick = SDL_GetTicks();
static const uint8 delays[3] = { 17, 17, 16 }; // 60 fps
#if 1
lastTick += delays[frameCtr % 3];
if (lastTick > curTick) {
uint32 delta = lastTick - curTick;
if (delta > 500) {
lastTick = curTick - 500;
delta = 500;
}
SDL_Delay(delta);
} else if (curTick - lastTick > 500) {
lastTick = curTick;
}
#endif
}
if (g_config.autosave)
SaveLoadSlot(kSaveLoad_Save, 0);
// clean snes
snes_free(snes);
// clean sdl
if (g_config.enable_audio) {
SDL_PauseAudioDevice(device, 1);
SDL_CloseAudioDevice(device);
}
free(audioBuffer);
SDL_DestroyTexture(texture);
SDL_DestroyRenderer(renderer);
SDL_DestroyWindow(window);
SDL_Quit();
//SaveConfigFile();
return 0;
}
static void PlayAudio(Snes *snes, SDL_AudioDeviceID device, int channels, int16 *audioBuffer) {
// generate enough samples
if (snes) {
while (snes->apu->dsp->sampleOffset < 534)
apu_cycle(snes->apu);
snes->apu->dsp->sampleOffset = 0;
}
dsp_getSamples(GetDspForRendering(), audioBuffer, g_samples_per_block, channels);
// Mixin the msu data?
if (channels == 2)
MixinMsuAudioData(audioBuffer, g_samples_per_block);
for (int i = 0; i < 10; i++) {
if (SDL_GetQueuedAudioSize(device) <= g_samples_per_block * channels * sizeof(int16) * 6) {
// don't queue audio if buffer is still filled
SDL_QueueAudio(device, audioBuffer, g_samples_per_block * channels * sizeof(int16));
return;
}
SDL_Delay(1);
}
}
static void RenderDigit(uint8 *dst, size_t pitch, int digit, uint32 color, bool big) {
static const uint8 kFont[] = {
0x1c, 0x36, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x36, 0x1c,
0x18, 0x1c, 0x1e, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x7e,
0x3e, 0x63, 0x60, 0x30, 0x18, 0x0c, 0x06, 0x03, 0x63, 0x7f,
0x3e, 0x63, 0x60, 0x60, 0x3c, 0x60, 0x60, 0x60, 0x63, 0x3e,
0x30, 0x38, 0x3c, 0x36, 0x33, 0x7f, 0x30, 0x30, 0x30, 0x78,
0x7f, 0x03, 0x03, 0x03, 0x3f, 0x60, 0x60, 0x60, 0x63, 0x3e,
0x1c, 0x06, 0x03, 0x03, 0x3f, 0x63, 0x63, 0x63, 0x63, 0x3e,
0x7f, 0x63, 0x60, 0x60, 0x30, 0x18, 0x0c, 0x0c, 0x0c, 0x0c,
0x3e, 0x63, 0x63, 0x63, 0x3e, 0x63, 0x63, 0x63, 0x63, 0x3e,
0x3e, 0x63, 0x63, 0x63, 0x7e, 0x60, 0x60, 0x60, 0x30, 0x1e,
};
const uint8 *p = kFont + digit * 10;
if (!big) {
for (int y = 0; y < 10; y++, dst += pitch) {
int v = *p++;
for (int x = 0; v; x++, v >>= 1) {
if (v & 1)
((uint32 *)dst)[x] = color;
}
}
} else {
for (int y = 0; y < 10; y++, dst += pitch * 2) {
int v = *p++;
for (int x = 0; v; x++, v >>= 1) {
if (v & 1) {
((uint32 *)dst)[x * 2 + 1] = ((uint32 *)dst)[x * 2] = color;
((uint32 *)(dst+pitch))[x * 2 + 1] = ((uint32 *)(dst + pitch))[x * 2] = color;
}
}
}
}
}
static void RenderNumber(uint8 *dst, size_t pitch, int n, bool big) {
char buf[32], *s;
int i;
sprintf(buf, "%d", n);
for (s = buf, i = 2 * 4; *s; s++, i += 8 * 4)
RenderDigit(dst + ((pitch + i + 4) << big), pitch, *s - '0', 0x404040, big);
for (s = buf, i = 2 * 4; *s; s++, i += 8 * 4)
RenderDigit(dst + (i << big), pitch, *s - '0', 0xffffff, big);
}
static void RenderScreen(SDL_Window *window, SDL_Renderer *renderer, SDL_Texture *texture, bool fullscreen) {
uint8* pixels = NULL;
int pitch = 0;
uint64 t0 = SDL_GetPerformanceCounter();
if(SDL_LockTexture(texture, NULL, (void**)&pixels, &pitch) != 0) {
printf("Failed to lock texture: %s\n", SDL_GetError());
return;
}
uint64 t1 = SDL_GetPerformanceCounter();
bool hq = RenderScreenWithPerf(pixels, pitch, g_ppu_render_flags);
if (g_display_perf) {
RenderNumber(pixels + (pitch * 2 << hq), pitch, g_curr_fps, hq);
}
if (g_config.display_perf_title) {
char title[60];
snprintf(title, sizeof(title), "%s | FPS: %d", kWindowTitle, g_curr_fps);
SDL_SetWindowTitle(window, title);
}
uint64 t2 = SDL_GetPerformanceCounter();
SDL_UnlockTexture(texture);
uint64 t3 = SDL_GetPerformanceCounter();
SDL_RenderClear(renderer);
uint64 t4 = SDL_GetPerformanceCounter();
SDL_Rect src_rect = { 0, 0, g_snes_width, g_snes_height };
SDL_RenderCopy(renderer, texture, hq ? NULL : &src_rect, NULL);
uint64 t5 = SDL_GetPerformanceCounter();
double f = 1e3 / (double)SDL_GetPerformanceFrequency();
if (0) printf("RenderPerf %6.2f %6.2f %6.2f %6.2f %6.2f\n",
(t1 - t0) * f,
(t2 - t1) * f,
(t3 - t2) * f,
(t4 - t3) * f,
(t5 - t4) * f
);
}
static void HandleCommand(uint32 j, bool pressed) {
if (j <= kKeys_Controls_Last) {
static const uint8 kKbdRemap[12] = { 4, 5, 6, 7, 2, 3, 8, 0, 9, 1, 10, 11 };
SetButtonState(kKbdRemap[j], pressed);
return;
}
if (!pressed)
return;
if (j <= kKeys_Load_Last) {
SaveLoadSlot(kSaveLoad_Load, j - kKeys_Load);
} else if (j <= kKeys_Save_Last) {
SaveLoadSlot(kSaveLoad_Save, j - kKeys_Save);
} else if (j <= kKeys_Replay_Last) {
SaveLoadSlot(kSaveLoad_Replay, j - kKeys_Replay);
} else if (j <= kKeys_LoadRef_Last) {
SaveLoadSlot(kSaveLoad_Load, 256 + j - kKeys_LoadRef);
} else if (j <= kKeys_ReplayRef_Last) {
SaveLoadSlot(kSaveLoad_Replay, 256 + j - kKeys_ReplayRef);
} else {
switch (j) {
case kKeys_CheatLife: PatchCommand('w'); break;
case kKeys_CheatEquipment: PatchCommand('W'); break;
case kKeys_CheatKeys: PatchCommand('o'); break;
case kKeys_ClearKeyLog: PatchCommand('k'); break;
case kKeys_StopReplay: PatchCommand('l'); break;
case kKeys_Fullscreen:
g_win_flags ^= SDL_WINDOW_FULLSCREEN_DESKTOP;
SDL_SetWindowFullscreen(g_window, g_win_flags & SDL_WINDOW_FULLSCREEN_DESKTOP);
g_cursor = !g_cursor;
SDL_ShowCursor(g_cursor);
break;
case kKeys_Reset:
snes_reset(g_snes, true);
ZeldaReadSram(g_snes);
CopyStateAfterSnapshotRestore(true);
break;
case kKeys_Pause: g_paused = !g_paused; break;
case kKeys_PauseDimmed:
g_paused = !g_paused;
if (g_paused) {
SDL_SetRenderDrawBlendMode(g_renderer, SDL_BLENDMODE_BLEND);
SDL_SetRenderDrawColor(g_renderer, 0, 0, 0, 159);
SDL_RenderFillRect(g_renderer, NULL);
SDL_RenderPresent(g_renderer);
}
break;
case kKeys_Turbo: g_turbo = !g_turbo; break;
case kKeys_WindowBigger: ChangeWindowScale(1); break;
case kKeys_WindowSmaller: ChangeWindowScale(-1); break;
case kKeys_DisplayPerf: g_display_perf ^= 1; break;
case kKeys_ToggleRenderer: g_ppu_render_flags ^= kPpuRenderFlags_NewRenderer; break;
default: assert(0);
}
}
}
static void HandleInput(int keyCode, int keyMod, bool pressed) {
int j = FindCmdForSdlKey(keyCode, keyMod);
if (j >= 0)
HandleCommand(j, pressed);
}
static void OpenOneGamepad(int i) {
if (SDL_IsGameController(i)) {
SDL_GameController *controller = SDL_GameControllerOpen(i);
if (!controller)
fprintf(stderr, "Could not open gamepad %d: %s\n", i, SDL_GetError());
}
}
static void HandleGamepadInput(int button, bool pressed) {
switch (button) {
case SDL_CONTROLLER_BUTTON_A: SetButtonState(0, pressed); break;
case SDL_CONTROLLER_BUTTON_X: SetButtonState(1, pressed); break;
case SDL_CONTROLLER_BUTTON_BACK: SetButtonState(2, pressed); break;
case SDL_CONTROLLER_BUTTON_START: SetButtonState(3, pressed); break;
case SDL_CONTROLLER_BUTTON_DPAD_UP: SetButtonState(4, pressed); break;
case SDL_CONTROLLER_BUTTON_DPAD_DOWN: SetButtonState(5, pressed); break;
case SDL_CONTROLLER_BUTTON_DPAD_LEFT: SetButtonState(6, pressed); break;
case SDL_CONTROLLER_BUTTON_DPAD_RIGHT: SetButtonState(7, pressed); break;
case SDL_CONTROLLER_BUTTON_B: SetButtonState(8, pressed); break;
case SDL_CONTROLLER_BUTTON_Y: SetButtonState(9, pressed); break;
case SDL_CONTROLLER_BUTTON_LEFTSHOULDER: SetButtonState(10, pressed); break;
case SDL_CONTROLLER_BUTTON_RIGHTSHOULDER: SetButtonState(11, pressed); break;
}
}
// Approximates atan2(y, x) normalized to the [0,4) range
// with a maximum error of 0.1620 degrees
// normalized_atan(x) ~ (b x + x^2) / (1 + 2 b x + x^2)
static float ApproximateAtan2(float y, float x) {
uint32 sign_mask = 0x80000000;
float b = 0.596227f;
// Extract the sign bits
uint32 ux_s = sign_mask & *(uint32 *)&x;
uint32 uy_s = sign_mask & *(uint32 *)&y;
// Determine the quadrant offset
float q = (float)((~ux_s & uy_s) >> 29 | ux_s >> 30);
// Calculate the arctangent in the first quadrant
float bxy_a = fabs(b * x * y);
float num = bxy_a + y * y;
float atan_1q = num / (x * x + bxy_a + num + 0.000001f);
// Translate it to the proper quadrant
uint32_t uatan_2q = (ux_s ^ uy_s) | *(uint32 *)&atan_1q;
return q + *(float *)&uatan_2q;
}
static void HandleGamepadAxisInput(int gamepad_id, int axis, int value) {
static int last_gamepad_id, last_x, last_y;
if (axis == SDL_CONTROLLER_AXIS_LEFTX || axis == SDL_CONTROLLER_AXIS_LEFTY) {
// ignore other gamepads unless they have a big input
if (last_gamepad_id != gamepad_id) {
if (value > -16000 && value < 16000)
return;
last_gamepad_id = gamepad_id;
last_x = last_y = 0;
}
*(axis == SDL_CONTROLLER_AXIS_LEFTX ? &last_x : &last_y) = value;
int buttons = 0;
if (last_x * last_x + last_y * last_y >= 10000 * 10000) {
// in the non deadzone part, divide the circle into eight 45 degree
// segments rotated by 22.5 degrees that control which direction to move.
// todo: do this without floats?
static const uint8 kSegmentToButtons[8] = {
1 << 4, // 0 = up
1 << 4 | 1 << 7, // 1 = up, right
1 << 7, // 2 = right
1 << 7 | 1 << 5, // 3 = right, down
1 << 5, // 4 = down
1 << 5 | 1 << 6, // 5 = down, left
1 << 6, // 6 = left
1 << 6 | 1 << 4, // 7 = left, up
};
uint8 angle = (uint8)(int)(ApproximateAtan2(last_y, last_x) * 64.0f + 0.5f);
buttons = kSegmentToButtons[(uint8)(angle + 16 + 64) >> 5];
}
g_gamepad_buttons = buttons;
}
}
static bool LoadRom(const char *name, Snes *snes) {
size_t length = 0;
uint8 *file = ReadFile(name, &length);
if(!file) Die("Failed to read file");
PatchRom(file);
bool result = snes_loadRom(snes, file, (int)length);
free(file);
return result;
}