little raylib example

reaction_time.c

#include <raylib.h>
#include <stdio.h>
#include <stdlib.h>

struct Target {
  Vector2 position;
  int size
};


int main(void)
{
  // Initialization
  const int screenWidth = 800;
  const int screenHeight = 450;

  int timer = 100;
  int reactionTime = 0;
  int lastReactionTime = 0;

  InitWindow(screenWidth, screenHeight, "raylib [core] example - keyboard input");

  Vector2 targetPosition = { (float)screenWidth/2 - 25, (float)screenHeight/2 - 25};

  struct Target target;
  char* reactionMessage;
  target.position = targetPosition;
  target.size = 50;

  Color targetColorPre = DARKBLUE;
  Color targetColorPost = RED;

  SetTargetFPS(60);

  // Main game loop
  while (!WindowShouldClose())
    {
      // Update
      if (timer > 0) {
        timer = timer - 1;
      }

      if (timer <= 0) {
        reactionTime = reactionTime + 1;
        if (IsMouseButtonPressed(MOUSE_LEFT_BUTTON)) {
          lastReactionTime = reactionTime;
          timer = 100;
          reactionTime = 0;
        }
      }

      BeginDrawing();

      ClearBackground(RAYWHITE);

      if (timer > 0) {
        DrawRectangle(target.position.x - (target.size / 2),
                      target.position.y - (target.size / 2),
                      target.size,
                      target.size,
                      targetColorPre);
      } else {
        DrawRectangle(target.position.x - (target.size / 2),
                      target.position.y - (target.size / 2),
                      target.size,
                      target.size,
                      targetColorPost);
      }

      if (lastReactionTime > 0) {

        if (0 < asprintf(&reactionMessage, "reaction time %i frames", lastReactionTime))
          DrawText(reactionMessage, 100, 300, 20, LIGHTGRAY);
      }

      DrawText("Reaction Time tester", 100, 200, 20, LIGHTGRAY);

      EndDrawing();
    }
  CloseWindow();
  return 0;
}