| r3dhatter |
05-30-2004 01:46 AM |
Tank Game Collision Detection and Bullets SDL/C++
How should I go about making the collision detection for the tanks, rocks, and tree's? Arrays?
Also, what should I use to make the bullets appear, and then move across the screen?
This is my first graphical game, so I am not too sure how do go about this, but I am willing to learn.
Any suggestions on fixing the code overall would be great too.
Thanks, and here's the code:
Code:
#include <SDL/SDL.h>
#define SCREEN_WIDTH 1024
#define SCREEN_HEIGHT 768
#define TANK_SIZE 32
//trying different arrays to work on collision detection
int main(int argc, char *argv[]) //*argv[3]
{
//argv[3] = "*rock, rcRock";
//argv[1] = "*tank, rcTank";
//argv[2] = "*tank2, rcTank2";
////////////////////
// VARIABLES //
///////////////////
SDL_Surface *screen, *temp, *sprite, *tank, *tank2, *grass, *rock, *tree, *bullet;
SDL_Rect rcTank, rcTank2, rcGrass, rcRock, rcTree, rcBullet;
SDL_Event event;
Uint8 *keystate;
int colorkey, gameover, position;
///////////////////
// END VARIABLES //
///////////////////
///////////////////
// LOAD GRAPHICS //
///////////////////
// initialize sdl
SDL_Init(SDL_INIT_VIDEO);
// window title
SDL_WM_SetCaption("Tank", "Tank");
screen = SDL_SetVideoMode(SCREEN_WIDTH, SCREEN_HEIGHT, 0, 0);
// load tank 1
temp = SDL_LoadBMP("tank.bmp");
tank = SDL_DisplayFormat(temp);
SDL_FreeSurface(temp);
// tank 1 color key
colorkey = SDL_MapRGB(screen->format, 255, 0, 255);
SDL_SetColorKey(tank, SDL_SRCCOLORKEY | SDL_RLEACCEL, colorkey);
// load tank 2
temp = SDL_LoadBMP("tank2.bmp");
tank2 = SDL_DisplayFormat(temp);
SDL_FreeSurface(temp);
// tank 2 color key
colorkey = SDL_MapRGB(screen->format, 255, 0, 255);
SDL_SetColorKey(tank2, SDL_SRCCOLORKEY | SDL_RLEACCEL, colorkey);
// load bullet
temp = SDL_LoadBMP("bullet.bmp");
bullet = SDL_DisplayFormat(temp);
SDL_FreeSurface(temp);
// bullet colorkey
colorkey = SDL_MapRGB(screen->format, 255, 0, 255);
SDL_SetColorKey(bullet, SDL_SRCCOLORKEY | SDL_RLEACCEL, colorkey);
// load grass
temp = SDL_LoadBMP("grass.bmp");
grass = SDL_DisplayFormat(temp);
SDL_FreeSurface(temp);
// load rock
temp = SDL_LoadBMP("rock.bmp");
rock = SDL_DisplayFormat(temp);
SDL_FreeSurface(temp);
// rock color key
colorkey = SDL_MapRGB(screen->format, 255, 0, 255);
SDL_SetColorKey(rock, SDL_SRCCOLORKEY | SDL_RLEACCEL, colorkey);
// load tree
temp = SDL_LoadBMP("tree.bmp");
tree = SDL_DisplayFormat(temp);
SDL_FreeSurface(temp);
// tree color key
colorkey = SDL_MapRGB(screen->format, 255, 0, 255);
SDL_SetColorKey(tree, SDL_SRCCOLORKEY | SDL_RLEACCEL, colorkey);
///////////////////////
// END LOAD GRAPHICS //
///////////////////////
/////////////////
// LOCATIONS ///
/////////////////
rcTank.x = 80;
rcTank.y = 80;
rcTank2.x = 900;
rcTank2.y = 600;
// NUETRAL UNITS //
rcRock.x = 200;
rcRock.y = 300;
rcTree.x = 250;
rcTree.y = 250;
gameover = 0;
while(!gameover)
{
// look for an event
if (SDL_PollEvent(&event)){
// event was found
switch (event.type){
// close button (X) clicked
case SDL_QUIT:
gameover = 1;
break;
// handle keyboard
case SDL_KEYDOWN:
switch (event.key.keysym.sym){
case SDLK_ESCAPE:
case SDLK_q:
gameover = 1;
break;
}
break;
}
}
////////////////////////////
// tank 1 movement //
////////////////////////////
keystate = SDL_GetKeyState(NULL);
if (keystate[SDLK_LEFT] ){
rcTank.x -= 2;
}
if (keystate[SDLK_RIGHT] ){
rcTank.x += 2;
}
if (keystate[SDLK_UP] ){
rcTank.y -= 2;
}
if (keystate[SDLK_DOWN] ){
rcTank.y += 2;
}
if (keystate[SDLK_SPACE] ){
SDL_BlitSurface(bullet, NULL, screen, &rcBullet);
SDL_UpdateRect(screen, 0, 0, 0, 0);
}
/////////////////////////
// COLLISION DETECTION //
/////////////////////////
if (rcTank.x < 0){
rcTank.x = 0;
}
else if (rcTank.x > SCREEN_WIDTH-TANK_SIZE){
rcTank.x = SCREEN_WIDTH-TANK_SIZE;
}
if (rcTank.y < 0){
rcTank.y = 0;
}
else if (rcTank.y > SCREEN_HEIGHT-TANK_SIZE){
rcTank.y = SCREEN_HEIGHT-TANK_SIZE;
}
// still trying to figure how I am going to input collision
// detection
///if (rcTank.x > 3)return(0);// || (rcTank.x 3)){
//if (rcTank.x*y == rcRock.x*y){
// rcTank.x -= rcRock.x;
// }
//if (rcTank.y == rcRock.y){
// rcTank.y -= rcRock.y;
// }
//
/// END ///
/*if (rcRock.x = 3){
rcRock.x = 3;
}
if (rcRock.y = 3){
rcRock.y = 3;
} */
/////////////////////////////////
// tank 2 movement //
/////////////////////////////////
keystate = SDL_GetKeyState(NULL);
if (keystate[SDLK_d] ){
rcTank2.x -= 2;
}
if (keystate[SDLK_g] ){
rcTank2.x += 2;
}
if (keystate[SDLK_r] ){
rcTank2.y -= 2;
}
if (keystate[SDLK_f] ){
rcTank2.y += 2;
}
if (rcTank2.x < 3 ){ // 0
rcTank2.x = 3;
}
else if (rcTank2.x > SCREEN_WIDTH-TANK_SIZE){
rcTank2.x = SCREEN_WIDTH-TANK_SIZE;
}
if (rcTank2.y < 3){
rcTank2.y = 3; // 0
}
else if (rcTank2.y > SCREEN_HEIGHT-TANK_SIZE){
rcTank2.y = SCREEN_HEIGHT-TANK_SIZE;
}
/// END ///
//////////////////////////
// DRAW SPRITES //
//////////////////////////
// draw grass //
for (int x = 0; x < SCREEN_WIDTH / TANK_SIZE; x++){
for (int y = 0; y < SCREEN_HEIGHT / TANK_SIZE; y++){
rcGrass.x = x * TANK_SIZE;
rcGrass.y = y * TANK_SIZE;
SDL_BlitSurface(grass, NULL, screen, &rcGrass);
}
}
// draw tank 1 //
SDL_BlitSurface(tank, NULL, screen, &rcTank);
// draw tank 2 //
SDL_BlitSurface(tank2, NULL, screen, &rcTank2);
// draw rock //
SDL_BlitSurface(rock, NULL, screen, &rcRock);
// draw tree //
SDL_BlitSurface(tree, NULL, screen, &rcTree);
///////////////////////
// END //
///////////////////////
// update screen //
SDL_UpdateRect(screen, 0, 0, 0, 0);
}
// clean up sdl //
SDL_FreeSurface(tank);
SDL_FreeSurface(tank2);
SDL_FreeSurface(grass);
SDL_FreeSurface(rock);
SDL_FreeSurface(bullet);
SDL_Quit();
return 0;
}
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