How to render text in SDL2?

Question

I'm using an SDL_Window and SDL_Renderer.

Is it possible to use SDL_TTF with SDL_Render/SDL_Window? If so, how?

Answer 1

Yep, it is possible, given that you have a renderer and a window plus you don't really have any thoughts on dabbling with surfaces then you might want to mind on creating texture, here is a sample code

//this opens a font style and sets a size TTF_Font* Sans = TTF_OpenFont("Sans.ttf", 24);  // this is the color in rgb format, // maxing out all would give you the color white, // and it will be your text's color SDL_Color White = {255, 255, 255};  // as TTF_RenderText_Solid could only be used on // SDL_Surface then you have to create the surface first SDL_Surface* surfaceMessage =     TTF_RenderText_Solid(Sans, "put your text here", White);   // now you can convert it into a texture SDL_Texture* Message = SDL_CreateTextureFromSurface(renderer, surfaceMessage);  SDL_Rect Message_rect; //create a rect Message_rect.x = 0;  //controls the rect's x coordinate  Message_rect.y = 0; // controls the rect's y coordinte Message_rect.w = 100; // controls the width of the rect Message_rect.h = 100; // controls the height of the rect  // (0,0) is on the top left of the window/screen, // think a rect as the text's box, // that way it would be very simple to understand  // Now since it's a texture, you have to put RenderCopy // in your game loop area, the area where the whole code executes  // you put the renderer's name first, the Message, // the crop size (you can ignore this if you don't want // to dabble with cropping), and the rect which is the size // and coordinate of your texture SDL_RenderCopy(renderer, Message, NULL, &Message_rect);  // Don't forget to free your surface and texture SDL_FreeSurface(surfaceMessage); SDL_DestroyTexture(Message); 

I tried to explain the code line by line, you don't see any window right there since I already assumed that you knew how to initialize a renderer which would give me an idea that you also know how to initialize a window, then all you need is the idea on how to initialize a texture.

Minor questions here, did your window open? was it colored black? if so then my thoughts were right, if not, then you can just ask me and I could change this code to implement the whole section which consists of a renderer and a window.

Answer 2

SDL_ttf minimal runnable example

Not super efficient, but easy to integrate. For efficiency see: How to render fonts and text with SDL2 efficiently?

Kept in a separate repo than the main SDL source, but hosted on the same official server, so should be fine: http://hg.libsdl.org/SDL_ttf/

Newlines won't work. You have to work with line heights.

Compile and run:

sudo apt-get install -y libsdl2-dev gcc -lSDL2 -lSDL2_ttf -o ttf ttf.c ./ttf /usr/share/fonts/truetype/freefont/FreeMonoOblique.ttf 

You must pass the path of a TTF font file to the program.

ttf.c

#include <stdlib.h>  #include <SDL2/SDL.h> #include <SDL2/SDL_ttf.h>  #define WINDOW_WIDTH 300 #define WINDOW_HEIGHT (WINDOW_WIDTH)  /* - x, y: upper left corner. - texture, rect: outputs. */ void get_text_and_rect(SDL_Renderer *renderer, int x, int y, char *text,         TTF_Font *font, SDL_Texture **texture, SDL_Rect *rect) {     int text_width;     int text_height;     SDL_Surface *surface;     SDL_Color textColor = {255, 255, 255, 0};      surface = TTF_RenderText_Solid(font, text, textColor);     *texture = SDL_CreateTextureFromSurface(renderer, surface);     text_width = surface->w;     text_height = surface->h;     SDL_FreeSurface(surface);     rect->x = x;     rect->y = y;     rect->w = text_width;     rect->h = text_height; }  int main(int argc, char **argv) {     SDL_Event event;     SDL_Rect rect1, rect2;     SDL_Renderer *renderer;     SDL_Texture *texture1, *texture2;     SDL_Window *window;     char *font_path;     int quit;      if (argc == 1) {         font_path = "FreeSans.ttf";     } else if (argc == 2) {         font_path = argv[1];     } else {         fprintf(stderr, "error: too many arguments\n");         exit(EXIT_FAILURE);     }      /* Inint TTF. */     SDL_Init(SDL_INIT_TIMER | SDL_INIT_VIDEO);     SDL_CreateWindowAndRenderer(WINDOW_WIDTH, WINDOW_WIDTH, 0, &window, &renderer);     TTF_Init();     TTF_Font *font = TTF_OpenFont(font_path, 24);     if (font == NULL) {         fprintf(stderr, "error: font not found\n");         exit(EXIT_FAILURE);     }     get_text_and_rect(renderer, 0, 0, "hello", font, &texture1, &rect1);     get_text_and_rect(renderer, 0, rect1.y + rect1.h, "world", font, &texture2, &rect2);      quit = 0;     while (!quit) {         while (SDL_PollEvent(&event) == 1) {             if (event.type == SDL_QUIT) {                 quit = 1;             }         }         SDL_SetRenderDrawColor(renderer, 0, 0, 0, 0);         SDL_RenderClear(renderer);          /* Use TTF textures. */         SDL_RenderCopy(renderer, texture1, NULL, &rect1);         SDL_RenderCopy(renderer, texture2, NULL, &rect2);          SDL_RenderPresent(renderer);     }      /* Deinit TTF. */     SDL_DestroyTexture(texture1);     SDL_DestroyTexture(texture2);     TTF_Quit();      SDL_DestroyRenderer(renderer);     SDL_DestroyWindow(window);     SDL_Quit();     return EXIT_SUCCESS; } 

GitHub upstream.

Tested in Ubuntu 16.04, SDL 2.0.4.