C++ SDL Reaction Time Game - c++

Question

Me and my friend needs to create a reaction time game.
Something like this.
Right now we just managed to show an image of the red button, but we need help how to make a hitbox, where if you click the red button, it becomes green.
Would someone could show us how?
We are using SDL, I guess that's important to mention.
Here is our code so far:
#include <SDL/SDL.h>
void Plot(SDL_Surface *sur, int x, int y, SDL_Surface *dest)
{
SDL_Rect rect = {x, y};
SDL_BlitSurface(sur, NULL, dest, &rect);
}
SDL_Surface *LoadImage(const char *filename)
{
SDL_Surface *sur = NULL;
sur = SDL_LoadBMP(filename);
if(sur == NULL)
{
printf("Img not found");
}
SDL_Surface *opsur = NULL;
if(sur != NULL)
{
opsur = SDL_DisplayFormat(sur);
SDL_SetColorKey(opsur, SDL_SRCCOLORKEY, 0xFFFFFF);
if(opsur != NULL)
SDL_FreeSurface(sur);
}
return opsur;
}
int main(int argc, char **argv)
{
SDL_Init(SDL_INIT_EVERYTHING);
SDL_Surface *screen = SDL_SetVideoMode(640, 480, 32, SDL_SWSURFACE);
SDL_WM_SetCaption("Eksamensprojekt", NULL);
SDL_Event Event;
bool Running = true;
SDL_Surface *sur = LoadImage("Red.bmp");
while(Running)
{
while(SDL_PollEvent(&Event))
{
if(Event.type == SDL_QUIT)
Running = false;
}
SDL_FillRect(screen, &screen->clip_rect, 0x000000);
Plot(sur, 215, 140, screen);
SDL_Flip(screen);
}
}

Answer 1

You can use SDL_Rect as a hit box. You can use SDL's own event handling system for checking when mouse button is clicked and the position of it. Then you just need to check if the mouse position is within the SDL_Rect.
You can read more about SDL here.
So... a little help on the way. You have a main loop and you pull events.
if ( event.type == SDL_MOUSEBUTTONDOWN ){
//Get mouse coordinates
int x = event.motion.x;
int y = event.motion.y;
//If the mouse is over the button
if( checkSpriteCollision( x, y ) ){
// Yay, you hit the button
doThings();
}
else
{
// D'oh I missed
}
}
Add this to the while, that will at least get you started.

Answer 2

Like this?
while(Running)
{
while(SDL_PollEvent(&Event))
{
if(Event.type == SDL_QUIT)
Running = false;
if ( event.type == SDL_MOUSEBUTTONDOWN ){
//Get mouse coordinates
int x = event.motion.x;
int y = event.motion.y;
//If the mouse is over the button
if( checkSpriteCollision( x, y ) ){
// Yay, you hit the button
doThings();
}
else {
// D'oh I missed
}
}
}
SDL_FillRect(screen, &screen->clip_rect, 0x000000);
Plot(sur, 215, 140, screen);
SDL_Flip(screen);
}
}