add FPS limit, G_sendWriteCharEvent function to write characters from other threads

src/graphics/sdl_event.h

@@ -0,0 +1,35 @@
+#ifndef SDL_event_h
+#define SDL_event_h
+
+#include <SDL.h>
+#include <stdlib.h>
+#include <graphics/sdl_error.h>
+
+typedef struct G_WriteCharEventData {
+    int x, y;
+    const char *c;
+    Uint32 color;
+} G_WriteCharEventData;
+
+int G_sendWriteCharEvent(int x, int y, const char c[256], Uint32 color) {
+    SDL_Event writeCharEvent;
+    writeCharEvent.type = SDL_USEREVENT;
+
+    G_WriteCharEventData *data = (G_WriteCharEventData*)malloc(sizeof(G_WriteCharEventData));
+    data->x = x;
+    data->y = y;
+    data->color = color;
+    data->c = c;
+
+    writeCharEvent.user.code = 37;
+    writeCharEvent.user.data1 = data;
+    writeCharEvent.user.timestamp = SDL_GetTicks();
+
+    int res = SDL_PushEvent(&writeCharEvent);
+
+    if (res == 1) return 0;
+    if (res == 0) return 1;
+    else G_error();
+}
+
+#endif

src/main.c

@@ -2,12 +2,16 @@
 #include "graphics/sdl_graphics.h"
 #include "graphics/sdl_error.h"
 #include "graphics/sdl_videomem.h"
+#include "graphics/sdl_event.h"
+
 #include "charset_debug.c"
 #include "charset.c"
 
 #include <stdlib.h>
 #include <string.h>
 
+static int fps = 25;
+
 void quit() {
     // Delete video memory
     G_deleteVideomem();
@@ -21,12 +25,19 @@ void handleEvent(SDL_Event e) {
     // User requests quit
     if (e.type == SDL_QUIT)
         quit();
-
-    if (e.type == SDL_KEYDOWN)
+    else if (e.type == SDL_KEYDOWN)
         {} // handle keydown
-    if (e.type == SDL_KEYUP)
+    else if (e.type == SDL_KEYUP)
         {} // handle keyup
+    else if (e.type == SDL_USEREVENT) {
+        if (e.user.code == 37) {
+            G_WriteCharEventData *data = e.user.data1;
 
+            G_writeChar(data->x, data->y, data->c, data->color);
+
+            free(data);
+        }
+    }
 }
 
 int main(int argc, char *argv[]) {
@@ -62,13 +73,20 @@ int main(int argc, char *argv[]) {
 
     // Execution loop
     for (;;) {
-        // run instruction
+        Uint64 ticksStart = SDL_GetTicks64();
 
         SDL_Event event;
         while (SDL_PollEvent(&event))
             handleEvent(event);
 
         G_render();
+
+        Uint64 ticksEnd = SDL_GetTicks64();
+
+        Uint64 ticksPassed = ticksEnd - ticksStart;
+        Uint64 ticksLeft = ticksPassed * 1000 / fps;
+
+        SDL_Delay(ticksLeft);
     }
 
     quit();