ref: cc5a879a848c161253bf5e9d543aaff70ac38ec2
dir: /textscreen/txt_sdl.c/
// // Copyright(C) 2005-2014 Simon Howard // // This program 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. // // This program 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. // // // Text mode emulation in SDL // #include "SDL.h" #include <ctype.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include "doomkeys.h" #include "txt_main.h" #include "txt_sdl.h" #include "txt_utf8.h" #if defined(_MSC_VER) && !defined(__cplusplus) #define inline __inline #endif typedef struct { const char *name; const uint8_t *data; unsigned int w; unsigned int h; } txt_font_t; // Fonts: #include "fonts/small.h" #include "fonts/normal.h" #include "fonts/large.h" #include "fonts/codepage.h" // Time between character blinks in ms #define BLINK_PERIOD 250 SDL_Window *TXT_SDLWindow; static SDL_Surface *screenbuffer; static unsigned char *screendata; static SDL_Renderer *renderer; // Current input mode. static txt_input_mode_t input_mode = TXT_INPUT_NORMAL; // Dimensions of the screen image in screen coordinates (not pixels); this // is the value that was passed to SDL_CreateWindow(). static int screen_image_w, screen_image_h; static TxtSDLEventCallbackFunc event_callback; static void *event_callback_data; // Font we are using: static const txt_font_t *font; // Dummy "font" that means to try highdpi rendering, or fallback to // normal_font otherwise. static const txt_font_t highdpi_font = { "normal-highdpi", NULL, 8, 16 }; // Mapping from SDL keyboard scancode to internal key code. static const int scancode_translate_table[] = SCANCODE_TO_KEYS_ARRAY; // String names of keys. This is a fallback; we usually use the SDL API. static const struct { int key; const char *name; } key_names[] = KEY_NAMES_ARRAY; // Unicode key mapping; see codepage.h. static const short code_page_to_unicode[] = CODE_PAGE_TO_UNICODE; static SDL_Color ega_colors[] = { {0x00, 0x00, 0x00, 0xff}, // 0: Black {0x00, 0x00, 0xa8, 0xff}, // 1: Blue {0x00, 0xa8, 0x00, 0xff}, // 2: Green {0x00, 0xa8, 0xa8, 0xff}, // 3: Cyan {0xa8, 0x00, 0x00, 0xff}, // 4: Red {0xa8, 0x00, 0xa8, 0xff}, // 5: Magenta {0xa8, 0x54, 0x00, 0xff}, // 6: Brown {0xa8, 0xa8, 0xa8, 0xff}, // 7: Grey {0x54, 0x54, 0x54, 0xff}, // 8: Dark grey {0x54, 0x54, 0xfe, 0xff}, // 9: Bright blue {0x54, 0xfe, 0x54, 0xff}, // 10: Bright green {0x54, 0xfe, 0xfe, 0xff}, // 11: Bright cyan {0xfe, 0x54, 0x54, 0xff}, // 12: Bright red {0xfe, 0x54, 0xfe, 0xff}, // 13: Bright magenta {0xfe, 0xfe, 0x54, 0xff}, // 14: Yellow {0xfe, 0xfe, 0xfe, 0xff}, // 15: Bright white }; #ifdef _WIN32 #define WIN32_LEAN_AND_MEAN #include <windows.h> // Examine system DPI settings to determine whether to use the large font. static int Win32_UseLargeFont(void) { HDC hdc = GetDC(NULL); int dpix; if (!hdc) { return 0; } dpix = GetDeviceCaps(hdc, LOGPIXELSX); ReleaseDC(NULL, hdc); // 144 is the DPI when using "150%" scaling. If the user has this set // then consider this an appropriate threshold for using the large font. return dpix >= 144; } #endif static const txt_font_t *FontForName(const char *name) { int i; const txt_font_t *fonts[] = { &small_font, &normal_font, &large_font, &highdpi_font, NULL, }; for (i = 0; fonts[i]->name != NULL; ++i) { if (!strcmp(fonts[i]->name, name)) { return fonts[i]; } } return NULL; } // // Select the font to use, based on screen resolution // // If the highest screen resolution available is less than // 640x480, use the small font. // static void ChooseFont(void) { SDL_DisplayMode desktop_info; char *env; // Allow normal selection to be overridden from an environment variable: env = getenv("TEXTSCREEN_FONT"); if (env != NULL) { font = FontForName(env); if (font != NULL) { return; } } // Get desktop resolution. // If in doubt and we can't get a list, always prefer to // fall back to the normal font: if (SDL_GetCurrentDisplayMode(0, &desktop_info)) { font = &highdpi_font; return; } // On tiny low-res screens (eg. palmtops) use the small font. // If the screen resolution is at least 1920x1080, this is // a modern high-resolution display, and we can use the // large font. if (desktop_info.w < 640 || desktop_info.h < 480) { font = &small_font; } #ifdef _WIN32 // On Windows we can use the system DPI settings to make a // more educated guess about whether to use the large font. else if (Win32_UseLargeFont()) { font = &large_font; } #endif // TODO: Detect high DPI on Linux by inquiring about Gtk+ scale // settings. This looks like it should just be a case of shelling // out to invoke the 'gsettings' command, eg. // gsettings get org.gnome.desktop.interface text-scaling-factor // and using large_font if the result is >= 2. else { // highdpi_font usually means normal_font (the normal resolution // version), but actually means "set the HIGHDPI flag and try // to use large_font if we initialize successfully". font = &highdpi_font; } } // // Initialize text mode screen // // Returns 1 if successful, 0 if an error occurred // int TXT_Init(void) { int flags = 0; if (SDL_Init(SDL_INIT_VIDEO) < 0) { return 0; } ChooseFont(); screen_image_w = TXT_SCREEN_W * font->w; screen_image_h = TXT_SCREEN_H * font->h; // If highdpi_font is selected, try to initialize high dpi rendering. if (font == &highdpi_font) { flags |= SDL_WINDOW_ALLOW_HIGHDPI; } TXT_SDLWindow = SDL_CreateWindow("", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, screen_image_w, screen_image_h, flags); if (TXT_SDLWindow == NULL) return 0; renderer = SDL_CreateRenderer(TXT_SDLWindow, -1, 0); // Special handling for OS X retina display. If we successfully set the // highdpi flag, check the output size for the screen renderer. If we get // the 2x doubled size we expect from a retina display, use the large font // for drawing the screen. if ((SDL_GetWindowFlags(TXT_SDLWindow) & SDL_WINDOW_ALLOW_HIGHDPI) != 0) { int render_w, render_h; if (SDL_GetRendererOutputSize(renderer, &render_w, &render_h) == 0 && render_w >= TXT_SCREEN_W * large_font.w && render_h >= TXT_SCREEN_H * large_font.h) { font = &large_font; // Note that we deliberately do not update screen_image_{w,h} // since these are the dimensions of textscreen image in screen // coordinates, not pixels. } } // Failed to initialize for high dpi (retina display) rendering? If so // then use the normal resolution font instead. if (font == &highdpi_font) { font = &normal_font; } // Instead, we draw everything into an intermediate 8-bit surface // the same dimensions as the screen. SDL then takes care of all the // 8->32 bit (or whatever depth) color conversions for us. screenbuffer = SDL_CreateRGBSurface(0, TXT_SCREEN_W * font->w, TXT_SCREEN_H * font->h, 8, 0, 0, 0, 0); SDL_LockSurface(screenbuffer); SDL_SetPaletteColors(screenbuffer->format->palette, ega_colors, 0, 16); SDL_UnlockSurface(screenbuffer); screendata = malloc(TXT_SCREEN_W * TXT_SCREEN_H * 2); memset(screendata, 0, TXT_SCREEN_W * TXT_SCREEN_H * 2); return 1; } void TXT_Shutdown(void) { free(screendata); screendata = NULL; SDL_FreeSurface(screenbuffer); screenbuffer = NULL; SDL_QuitSubSystem(SDL_INIT_VIDEO); } unsigned char *TXT_GetScreenData(void) { return screendata; } static inline void UpdateCharacter(int x, int y) { unsigned char character; const uint8_t *p; unsigned char *s, *s1; unsigned int bit; int bg, fg; unsigned int x1, y1; p = &screendata[(y * TXT_SCREEN_W + x) * 2]; character = p[0]; fg = p[1] & 0xf; bg = (p[1] >> 4) & 0xf; if (bg & 0x8) { // blinking bg &= ~0x8; if (((SDL_GetTicks() / BLINK_PERIOD) % 2) == 0) { fg = bg; } } // How many bytes per line? p = &font->data[(character * font->w * font->h) / 8]; bit = 0; s = ((unsigned char *) screenbuffer->pixels) + (y * font->h * screenbuffer->pitch) + (x * font->w); for (y1=0; y1<font->h; ++y1) { s1 = s; for (x1=0; x1<font->w; ++x1) { if (*p & (1 << bit)) { *s1++ = fg; } else { *s1++ = bg; } ++bit; if (bit == 8) { ++p; bit = 0; } } s += screenbuffer->pitch; } } static int LimitToRange(int val, int min, int max) { if (val < min) { return min; } else if (val > max) { return max; } else { return val; } } static void GetDestRect(SDL_Rect *rect) { int w, h; SDL_GetRendererOutputSize(renderer, &w, &h); rect->x = (w - screenbuffer->w) / 2; rect->y = (h - screenbuffer->h) / 2; rect->w = screenbuffer->w; rect->h = screenbuffer->h; } void TXT_UpdateScreenArea(int x, int y, int w, int h) { SDL_Texture *screentx; SDL_Rect rect; int x1, y1; int x_end; int y_end; SDL_LockSurface(screenbuffer); x_end = LimitToRange(x + w, 0, TXT_SCREEN_W); y_end = LimitToRange(y + h, 0, TXT_SCREEN_H); x = LimitToRange(x, 0, TXT_SCREEN_W); y = LimitToRange(y, 0, TXT_SCREEN_H); for (y1=y; y1<y_end; ++y1) { for (x1=x; x1<x_end; ++x1) { UpdateCharacter(x1, y1); } } SDL_UnlockSurface(screenbuffer); SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "linear"); // TODO: This is currently creating a new texture every time we render // the screen; find a more efficient way to do it. screentx = SDL_CreateTextureFromSurface(renderer, screenbuffer); SDL_RenderClear(renderer); GetDestRect(&rect); SDL_RenderCopy(renderer, screentx, NULL, &rect); SDL_RenderPresent(renderer); SDL_DestroyTexture(screentx); } void TXT_UpdateScreen(void) { TXT_UpdateScreenArea(0, 0, TXT_SCREEN_W, TXT_SCREEN_H); } void TXT_GetMousePosition(int *x, int *y) { int window_w, window_h; int origin_x, origin_y; SDL_GetMouseState(x, y); // Translate mouse position from 'pixel' position into character position. // We are working here in screen coordinates and not pixels, since this is // what SDL_GetWindowSize() returns; we must calculate and subtract the // origin position since we center the image within the window. SDL_GetWindowSize(TXT_SDLWindow, &window_w, &window_h); origin_x = (window_w - screen_image_w) / 2; origin_y = (window_h - screen_image_h) / 2; *x = ((*x - origin_x) * TXT_SCREEN_W) / screen_image_w; *y = ((*y - origin_y) * TXT_SCREEN_H) / screen_image_h; if (*x < 0) { *x = 0; } else if (*x >= TXT_SCREEN_W) { *x = TXT_SCREEN_W - 1; } if (*y < 0) { *y = 0; } else if (*y >= TXT_SCREEN_H) { *y = TXT_SCREEN_H - 1; } } // // Translates the SDL key // // XXX: duplicate from doomtype.h #define arrlen(array) (sizeof(array) / sizeof(*array)) static int TranslateScancode(SDL_Scancode scancode) { switch (scancode) { case SDL_SCANCODE_LCTRL: case SDL_SCANCODE_RCTRL: return KEY_RCTRL; case SDL_SCANCODE_LSHIFT: case SDL_SCANCODE_RSHIFT: return KEY_RSHIFT; case SDL_SCANCODE_LALT: return KEY_LALT; case SDL_SCANCODE_RALT: return KEY_RALT; default: if (scancode < arrlen(scancode_translate_table)) { return scancode_translate_table[scancode]; } else { return 0; } } } static int TranslateKeysym(const SDL_Keysym *sym) { int translated; // We cheat here and make use of TranslateScancode. The range of keys // associated with printable characters is pretty contiguous, so if it's // inside that range we want the localized version of the key instead. translated = TranslateScancode(sym->scancode); if (translated >= 0x20 && translated < 0x7f) { return sym->sym; } else { return translated; } } // Convert an SDL button index to textscreen button index. // // Note special cases because 2 == mid in SDL, 3 == mid in textscreen/setup static int SDLButtonToTXTButton(int button) { switch (button) { case SDL_BUTTON_LEFT: return TXT_MOUSE_LEFT; case SDL_BUTTON_RIGHT: return TXT_MOUSE_RIGHT; case SDL_BUTTON_MIDDLE: return TXT_MOUSE_MIDDLE; default: return TXT_MOUSE_BASE + button - 1; } } // Convert an SDL wheel motion to a textscreen button index. static int SDLWheelToTXTButton(const SDL_MouseWheelEvent *wheel) { if (wheel->y <= 0) { return TXT_MOUSE_SCROLLDOWN; } else { return TXT_MOUSE_SCROLLUP; } } static int MouseHasMoved(void) { static int last_x = 0, last_y = 0; int x, y; TXT_GetMousePosition(&x, &y); if (x != last_x || y != last_y) { last_x = x; last_y = y; return 1; } else { return 0; } } signed int TXT_GetChar(void) { SDL_Event ev; while (SDL_PollEvent(&ev)) { // If there is an event callback, allow it to intercept this // event. if (event_callback != NULL) { if (event_callback(&ev, event_callback_data)) { continue; } } // Process the event. switch (ev.type) { case SDL_MOUSEBUTTONDOWN: if (ev.button.button < TXT_MAX_MOUSE_BUTTONS) { return SDLButtonToTXTButton(ev.button.button); } break; case SDL_MOUSEWHEEL: return SDLWheelToTXTButton(&ev.wheel); case SDL_KEYDOWN: switch (input_mode) { case TXT_INPUT_RAW: return TranslateScancode(ev.key.keysym.scancode); case TXT_INPUT_NORMAL: return TranslateKeysym(&ev.key.keysym); case TXT_INPUT_TEXT: // We ignore key inputs in this mode, except for a // few special cases needed during text input: if (ev.key.keysym.sym == SDLK_ESCAPE || ev.key.keysym.sym == SDLK_BACKSPACE || ev.key.keysym.sym == SDLK_RETURN) { return TranslateKeysym(&ev.key.keysym); } break; } break; case SDL_TEXTINPUT: if (input_mode == TXT_INPUT_TEXT) { // TODO: Support input of more than just the first char? const char *p = ev.text.text; int result = TXT_DecodeUTF8(&p); // 0-127 is ASCII, but we map non-ASCII Unicode chars into // a higher range to avoid conflicts with special keys. return TXT_UNICODE_TO_KEY(result); } break; case SDL_QUIT: // Quit = escape return 27; case SDL_MOUSEMOTION: if (MouseHasMoved()) { return 0; } default: break; } } return -1; } int TXT_GetModifierState(txt_modifier_t mod) { SDL_Keymod state; state = SDL_GetModState(); switch (mod) { case TXT_MOD_SHIFT: return (state & KMOD_SHIFT) != 0; case TXT_MOD_CTRL: return (state & KMOD_CTRL) != 0; case TXT_MOD_ALT: return (state & KMOD_ALT) != 0; default: return 0; } } int TXT_UnicodeCharacter(unsigned int c) { unsigned int i; // Check the code page mapping to see if this character maps // to anything. for (i = 0; i < arrlen(code_page_to_unicode); ++i) { if (code_page_to_unicode[i] == c) { return i; } } return -1; } // Returns true if the given UTF8 key name is printable to the screen. static int PrintableName(const char *s) { const char *p; unsigned int c; p = s; while (*p != '\0') { c = TXT_DecodeUTF8(&p); if (TXT_UnicodeCharacter(c) < 0) { return 0; } } return 1; } static const char *NameForKey(int key) { const char *result; int i; // Overrides purely for aesthetical reasons, so that default // window accelerator keys match those of setup.exe. switch (key) { case KEY_ESCAPE: return "ESC"; case KEY_ENTER: return "ENTER"; default: break; } // This key presumably maps to a scan code that is listed in the // translation table. Find which mapping and once we have a scancode, // we can convert it into a virtual key, then a string via SDL. for (i = 0; i < arrlen(scancode_translate_table); ++i) { if (scancode_translate_table[i] == key) { result = SDL_GetKeyName(SDL_GetKeyFromScancode(i)); if (TXT_UTF8_Strlen(result) > 6 || !PrintableName(result)) { break; } return result; } } // Use US English fallback names, if the localized name is too long, // not found in the scancode table, or contains unprintable chars // (non-extended ASCII character set): for (i = 0; i < arrlen(key_names); ++i) { if (key_names[i].key == key) { return key_names[i].name; } } return NULL; } void TXT_GetKeyDescription(int key, char *buf, size_t buf_len) { const char *keyname; int i; keyname = NameForKey(key); if (keyname != NULL) { TXT_StringCopy(buf, keyname, buf_len); // Key description should be all-uppercase to match setup.exe. for (i = 0; buf[i] != '\0'; ++i) { buf[i] = toupper(buf[i]); } } else { TXT_snprintf(buf, buf_len, "??%i", key); } } // Searches the desktop screen buffer to determine whether there are any // blinking characters. int TXT_ScreenHasBlinkingChars(void) { int x, y; unsigned char *p; // Check all characters in screen buffer for (y=0; y<TXT_SCREEN_H; ++y) { for (x=0; x<TXT_SCREEN_W; ++x) { p = &screendata[(y * TXT_SCREEN_W + x) * 2]; if (p[1] & 0x80) { // This character is blinking return 1; } } } // None found return 0; } // Sleeps until an event is received, the screen needs to be redrawn, // or until timeout expires (if timeout != 0) void TXT_Sleep(int timeout) { unsigned int start_time; if (TXT_ScreenHasBlinkingChars()) { int time_to_next_blink; time_to_next_blink = BLINK_PERIOD - (SDL_GetTicks() % BLINK_PERIOD); // There are blinking characters on the screen, so we // must time out after a while if (timeout == 0 || timeout > time_to_next_blink) { // Add one so it is always positive timeout = time_to_next_blink + 1; } } if (timeout == 0) { // We can just wait forever until an event occurs SDL_WaitEvent(NULL); } else { // Sit in a busy loop until the timeout expires or we have to // redraw the blinking screen start_time = SDL_GetTicks(); while (SDL_GetTicks() < start_time + timeout) { if (SDL_PollEvent(NULL) != 0) { // Received an event, so stop waiting break; } // Don't hog the CPU SDL_Delay(1); } } } void TXT_SetInputMode(txt_input_mode_t mode) { if (mode == TXT_INPUT_TEXT && !SDL_IsTextInputActive()) { SDL_StartTextInput(); } else if (SDL_IsTextInputActive() && mode != TXT_INPUT_TEXT) { SDL_StopTextInput(); } input_mode = mode; } void TXT_SetWindowTitle(const char *title) { SDL_SetWindowTitle(TXT_SDLWindow, title); } void TXT_SDL_SetEventCallback(TxtSDLEventCallbackFunc callback, void *user_data) { event_callback = callback; event_callback_data = user_data; } // Safe string functions. void TXT_StringCopy(char *dest, const char *src, size_t dest_len) { if (dest_len < 1) { return; } dest[dest_len - 1] = '\0'; strncpy(dest, src, dest_len - 1); } void TXT_StringConcat(char *dest, const char *src, size_t dest_len) { size_t offset; offset = strlen(dest); if (offset > dest_len) { offset = dest_len; } TXT_StringCopy(dest + offset, src, dest_len - offset); } // On Windows, vsnprintf() is _vsnprintf(). #ifdef _WIN32 #if _MSC_VER < 1400 /* not needed for Visual Studio 2008 */ #define vsnprintf _vsnprintf #endif #endif // Safe, portable vsnprintf(). int TXT_vsnprintf(char *buf, size_t buf_len, const char *s, va_list args) { int result; if (buf_len < 1) { return 0; } // Windows (and other OSes?) has a vsnprintf() that doesn't always // append a trailing \0. So we must do it, and write into a buffer // that is one byte shorter; otherwise this function is unsafe. result = vsnprintf(buf, buf_len, s, args); // If truncated, change the final char in the buffer to a \0. // A negative result indicates a truncated buffer on Windows. if (result < 0 || result >= buf_len) { buf[buf_len - 1] = '\0'; result = buf_len - 1; } return result; } // Safe, portable snprintf(). int TXT_snprintf(char *buf, size_t buf_len, const char *s, ...) { va_list args; int result; va_start(args, s); result = TXT_vsnprintf(buf, buf_len, s, args); va_end(args); return result; }