keii.dev
1/*
2 * This example creates an SDL window and renderer, and then draws some text
3 * using SDL_RenderDebugText() every frame.
4 *
5 * This code is public domain. Feel free to use it for any purpose!
6 */
7
8#define SDL_MAIN_USE_CALLBACKS 1 /* use the callbacks instead of main() */
9#include <SDL3/SDL.h>
10#include <SDL3/SDL_main.h>
11
12/* We will use this renderer to draw into this window every frame. */
13static SDL_Window *window = NULL;
14static SDL_Renderer *renderer = NULL;
15
16#define WINDOW_WIDTH 640
17#define WINDOW_HEIGHT 480
18
19/* This function runs once at startup. */
20SDL_AppResult SDL_AppInit(void **appstate, int argc, char *argv[])
21{
22 SDL_SetAppMetadata("Example Renderer Debug Texture", "1.0", "com.example.renderer-debug-text");
23
24 if (!SDL_Init(SDL_INIT_VIDEO)) {
25 SDL_Log("Couldn't initialize SDL: %s", SDL_GetError());
26 return SDL_APP_FAILURE;
27 }
28
29 if (!SDL_CreateWindowAndRenderer("examples/renderer/debug-text", WINDOW_WIDTH, WINDOW_HEIGHT, 0, &window, &renderer)) {
30 SDL_Log("Couldn't create window/renderer: %s", SDL_GetError());
31 return SDL_APP_FAILURE;
32 }
33
34 return SDL_APP_CONTINUE; /* carry on with the program! */
35}
36
37/* This function runs when a new event (mouse input, keypresses, etc) occurs. */
38SDL_AppResult SDL_AppEvent(void *appstate, SDL_Event *event)
39{
40 if (event->type == SDL_EVENT_QUIT) {
41 return SDL_APP_SUCCESS; /* end the program, reporting success to the OS. */
42 }
43 return SDL_APP_CONTINUE; /* carry on with the program! */
44}
45
46/* This function runs once per frame, and is the heart of the program. */
47SDL_AppResult SDL_AppIterate(void *appstate)
48{
49 const int charsize = SDL_DEBUG_TEXT_FONT_CHARACTER_SIZE;
50
51 /* as you can see from this, rendering draws over whatever was drawn before it. */
52 SDL_SetRenderDrawColor(renderer, 0, 0, 0, SDL_ALPHA_OPAQUE); /* black, full alpha */
53 SDL_RenderClear(renderer); /* start with a blank canvas. */
54
55 SDL_SetRenderDrawColor(renderer, 255, 255, 255, SDL_ALPHA_OPAQUE); /* white, full alpha */
56 SDL_RenderDebugText(renderer, 272, 100, "Hello world!");
57 SDL_RenderDebugText(renderer, 224, 150, "This is some debug text.");
58
59 SDL_SetRenderDrawColor(renderer, 51, 102, 255, SDL_ALPHA_OPAQUE); /* light blue, full alpha */
60 SDL_RenderDebugText(renderer, 184, 200, "You can do it in different colors.");
61 SDL_SetRenderDrawColor(renderer, 255, 255, 255, SDL_ALPHA_OPAQUE); /* white, full alpha */
62
63 SDL_SetRenderScale(renderer, 4.0f, 4.0f);
64 SDL_RenderDebugText(renderer, 14, 65, "It can be scaled.");
65 SDL_SetRenderScale(renderer, 1.0f, 1.0f);
66 SDL_RenderDebugText(renderer, 64, 350, "This only does ASCII chars. So this laughing emoji won't draw: 🤣");
67
68 SDL_RenderDebugTextFormat(renderer, (float) ((WINDOW_WIDTH - (charsize * 46)) / 2), 400, "(This program has been running for %" SDL_PRIu64 " seconds.)", SDL_GetTicks() / 1000);
69
70 SDL_RenderPresent(renderer); /* put it all on the screen! */
71
72 return SDL_APP_CONTINUE; /* carry on with the program! */
73}
74
75/* This function runs once at shutdown. */
76void SDL_AppQuit(void *appstate, SDL_AppResult result)
77{
78 /* SDL will clean up the window/renderer for us. */
79}
80