ref: 2e231162fee12ebe546a06e92cb6f2f4c25931f5
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; f |= g_config.skip_intro_on_keypress * kFeatures0_SkipIntroOnKeypress; f |= g_config.show_max_items_in_yellow * kFeatures0_ShowMaxItemsInYellow; 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; }