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This thread is locked; no one can reply to it.
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| How to remove magnetic effect in collision! |
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varynoob
Member #14,058
February 2012
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Hello everyone, Looking for some realism in collision and updation, i mean i have a ball in centre, squares coming from right to left, 1for(int i=0; i < ssize ; i++)
2 {
3 if(shapeS[i].live) // checks whether the square is on the screen
4 {
5 if(((shapeS[i].pos_rect_x1 < shapeB.pos_X + shapeB.boundx +7)
6 &&(shapeS[i].pos_rect_x1+ 40 > shapeB.pos_X - shapeB.boundx))
7 &&!((shapeS[i].pos_rect_y1 < shapeB.pos_Y + shapeB.boundy)
8 &&(shapeS[i].pos_rect_y1+40 > shapeB.pos_Y - shapeB.boundy)))// basic collision detection for top
9 {
10 shapeB.LeftCollision = false;
11 shapeB.pos_Y = shapeS[i].pos_rect_y1 - shapeB.boundy - 7 ; // this updates ball position and causes magnetic effect
12 shapeB.isOnSquare = true;
13 }
14
15 else if((shapeS[i].pos_rect_x1 < shapeB.pos_X + shapeB.boundx+ 7)
16 &&(shapeS[i].pos_rect_x1 > shapeB.pos_X - shapeB.boundx)) // checks for left collision
17 {
18 shapeB.LeftCollision = true;
19 }
20
21 else
22 {
23 shapeB.LeftCollision = false;
24
25 }
26 }
27 }
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Steve Terry
Member #1,989
March 2002
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You are only snapping y to the top of the box, if you want to make it roll off you need to apply gravity and forward momentum. ___________________________________ |
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varynoob
Member #14,058
February 2012
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Is it like, adding and && comdition in the JUMP mechanism ? (!isOnGround && LeftCollision) ? ? How do i apply forward momentum ? ? |
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Steve Terry
Member #1,989
March 2002
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changing anything in your if statement won't get the ball rolling forward. You will need to post more code if we are to figure out how to apply forward momentum. Usually it just means incrementing x. ___________________________________ |
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varynoob
Member #14,058
February 2012
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The code goes as this(excluding code fr BG, Explosions, Globals, main() part b4 game loop), so where do i apply momentum ? How do i go for it, i understand it is just some logic, but what i want to ask is, should i take triangle and square in the same struct and same loop in else if conditions or do as i have done here with different structs. I can attach the setup as well, if needed, the game is running, but with triangle-triangle overlap and square-triangle overlap and that magnetic effect!! 1
2/***********************
3 GAME LOOP
4************************/
5 while(!done)
6 {
7 ALLEGRO_EVENT ev;
8 al_wait_for_event(event_queue, &ev);
9
10
11 time_remaining --;
12 if((time_remaining/60) % 3 == 0)
13 inc_speed +=0.001;
14
15
16 if(ev.type == ALLEGRO_EVENT_KEY_DOWN)
17 {
18 switch(ev.keyboard.keycode)
19 {
20 case ALLEGRO_KEY_LEFT:
21 keys[LEFT] = true;
22 break;
23 case ALLEGRO_KEY_RIGHT:
24 keys[RIGHT] = true;
25 break;
26 case ALLEGRO_KEY_SPACE:
27 keys[SPACE] = true;
28 if(state == TITLE)
29 ChangeState(state, PLAYING);
30 else if(state == LOST)
31 ChangeState(state, PLAYING);
32
33 break;
34
35 }
36
37 }
38 else if(ev.type == ALLEGRO_EVENT_KEY_UP)
39 {
40 switch(ev.keyboard.keycode)
41 {
42 case ALLEGRO_KEY_LEFT:
43 keys[LEFT] = false;
44 break;
45 case ALLEGRO_KEY_RIGHT:
46 keys[RIGHT] = false;
47 break;
48 case ALLEGRO_KEY_ESCAPE:
49 done=true;
50 break;
51 case ALLEGRO_KEY_SPACE:
52 keys[SPACE] = false;
53 break;
54 }
55 }
56 else if(ev.type == ALLEGRO_EVENT_DISPLAY_CLOSE)
57 {
58 done = true;
59 }
60
61 /***********************
62 UPDATE
63 ************************/
64
65
66 else if(ev.type == ALLEGRO_EVENT_TIMER)
67 {
68 redraw = true;
69 /*if(keys[LEFT])
70 MoveLeftBall(shapeB);
71 if(keys[RIGHT])
72 MoveRightBall(shapeB);*/
73
74
75
76 if (shapeB.isOnGround || shapeB.isOnSquare )
77 { // means the ball is on the ground
78 if(keys[SPACE])
79 {
80 if (shapeB.canJump) //CAN JUMP
81 {
82 shapeB.dy= -10; //VELOCITY UPWARDS
83 shapeB.canJump = false;
84 }
85 }
86 else
87 shapeB.canJump = true;
88 }
89
90
91
92 if(!shapeB.isOnGround || !shapeB.isOnSquare)
93 {
94 shapeB.dy += 0.5;
95 speed = 5+inc_speed ;
96 }
97 else
98 speed = 3+inc_speed;
99
100 if (keys[SPACE] && shapeB.isOnGround && shapeB.isOnSquare && shapeB.dy > 0)
101 shapeB.dy -= 0.1; // got to be LESS than 0.5 here.
102
103 if(shapeB.dy>5)
104 shapeB.dy = 5;
105
106 shapeB.pos_Y += shapeB.dy;
107
108 if(shapeB.pos_Y > HEIGHT-20)
109 {
110 shapeB.pos_Y = HEIGHT-20;
111 shapeB.dy = 0;
112 }
113
114
115 if(state == TITLE)
116 {}
117 else if(state == PLAYING)
118 {
119 if(shapeB.LeftCollision == false)
120 {
121
122 UpdateBackground(BG);
123
124 UpdateTriangle(shapeT,NUM_TRIANGLES, shapeB);
125
126 UpdateSquare(shapeS,NUM_TRIANGLES, shapeB);
127 }
128 UpdateExplosions(explosions);
129 UpdateBall(shapeB);
130 StartTriangle(shapeT, NUM_TRIANGLES);
131 StartSquare(shapeS, NUM_TRIANGLES);
132 CollideTriangle(shapeT,shapeS, NUM_TRIANGLES, shapeB, explosions);
133 CollideSquare(shapeS, NUM_TRIANGLES, shapeB, explosions);
134 if(shapeB.lives <=0 || time_remaining < 1)
135 ChangeState(state, LOST);
136 }
137 else if(state == LOST)
138 {}
139
140
141 /***********************
142 RENDERING
143 ************************/
144
145
146 if(redraw && al_is_event_queue_empty(event_queue))
147 {
148 redraw= false;
149
150 if(state == TITLE)
151 {
152 al_draw_bitmap(title, 0 ,0 ,0);
153 }
154 else if(state == PLAYING)
155 {
156 DrawBackground(BG);
157 DrawBall(shapeB);
158 DrawTriangle(shapeT,NUM_TRIANGLES);
159 DrawSquare(shapeS,NUM_TRIANGLES);
160 DrawExplosions(explosions);
161
162 al_draw_textf(font18, al_map_rgb(255,255,255),0,0,0,
163 "Player has %i lives. Score : %i",shapeB.lives,shapeB.score);
164
165 al_draw_textf(font18, al_map_rgb(255,255,255),600,0,0,
166 "Time Remaining: %i",time_remaining/60);
167
168 }
169 else if(state == LOST)
170 {
171 al_draw_bitmap(lost, 0, 0, 0);
172 al_draw_textf(font18, al_map_rgb(0,255,255),WIDTH - 10 ,20,ALLEGRO_ALIGN_RIGHT,
173 "Final Score : %i",shapeB.score);
174 }
175
176
177 al_flip_display();
178 al_clear_to_color(al_map_rgb(0,0,0));
179
180 }
181 }
182
183 }
184
185 /**********************************
186 DESTROYING GAME OBJECTS
187 **********************************/
188
189 al_destroy_sample(boom);
190 al_destroy_sample_instance(songInstance);
191 al_destroy_bitmap(bgImage);
192 al_destroy_bitmap(title);
193 al_destroy_bitmap(lost);
194 al_destroy_bitmap(expImage);
195 al_destroy_bitmap(ballImage);
196 al_destroy_event_queue(event_queue);
197 al_destroy_timer(timer);
198 al_destroy_font(font18);
199 al_destroy_display(display);
200
201 return 0;
202}
203
204
205
206void InitBall(Ball &shapeB, ALLEGRO_BITMAP *image = NULL)
207{
208 shapeB.ID=BALL;
209 shapeB.pos_X= WIDTH/2;
210 shapeB.pos_Y= HEIGHT;
211 shapeB.lives = 3;
212 shapeB.speed = 6;
213 shapeB.score = 0;
214 shapeB.boundx = 23;
215 shapeB.boundy = 16;
216 shapeB.dx = 1;
217 shapeB.dy = 1;
218 shapeB.canJump = false;
219 shapeB.isOnGround = true;
220 shapeB.isOnSquare = false;
221 shapeB.LeftCollision = false;
222
223 shapeB.maxFrame = 8;
224 shapeB.curFrame = 0;
225 shapeB.frameCount = 0;
226 shapeB.frameDelay = 5;
227 shapeB.frameWidth = 64;
228 shapeB.frameHeight = 48;
229 shapeB.animationColumns = 8;
230 shapeB.animationDirection = 1;
231 shapeB.animationRow = 0;
232
233 time_remaining = 10800; //A calculated value to display remainging time
234 speed=0;
235 inc_speed=0;
236
237 if(image != NULL)
238 shapeB.image = image;
239
240}
241void DrawBall(Ball &shapeB)
242{
243
244 int fx = (shapeB.curFrame % shapeB.animationColumns) * shapeB.frameWidth;
245 int fy = shapeB.animationRow * shapeB.frameHeight;
246
247 al_draw_bitmap_region(shapeB.image, fx, fy, shapeB.frameWidth,
248 shapeB.frameHeight, (shapeB.pos_X - shapeB.frameWidth/2), (shapeB.pos_Y - shapeB.frameHeight/2), 0);
249
250 //al_draw_filled_rectangle(shapeB.pos_X - shapeB.boundx, shapeB.pos_Y - shapeB.boundy,
251 // shapeB.pos_X + shapeB.boundx, shapeB.pos_Y + shapeB.boundy, al_map_rgba(255,0,255,100));
252
253
254}
255//void MoveLeftBall(Ball &shapeB)
256//{
257// shapeB.pos_X -=shapeB.speed;
258// if(shapeB.pos_X <(WIDTH/2) - 100)
259// shapeB.pos_X = (WIDTH/2) - 100;
260//}
261//void MoveRightBall(Ball &shapeB)
262//{
263// shapeB.pos_X += shapeB.speed;
264// if(shapeB.pos_X >(WIDTH/2)+100)
265// shapeB.pos_X = (WIDTH/2)+100 ;
266//}
267
268
269void UpdateBall(Ball &shapeB)
270{
271 if(shapeB.pos_Y < HEIGHT-20)
272 shapeB.isOnGround = false;
273 else
274 shapeB.isOnGround = true;
275
276 if(!shapeB.LeftCollision)
277 {
278 if(++shapeB.frameCount >= shapeB.frameDelay)
279 {
280 if(++shapeB.curFrame >= shapeB.maxFrame)
281 {
282 shapeB.curFrame = 0;
283
284 }
285
286 shapeB.frameCount = 0;
287
288 }
289
290 }
291}
292
293
294void InitTriangle(Triangle shapeT[], int size)
295{
296 for(int i=0; i<size; i++)
297 {
298 shapeT[i].ID = TRIANGLE;
299 shapeT[i].live = false;
300
301
302 shapeT[i].bound_triangle_x = 10;
303 shapeT[i].bound_triangle_y = 16;
304 shapeT[i].collidingS = false;
305 shapeT[i].collidingT = false;
306
307 }
308}
309
310void DrawTriangle(Triangle shapeT[], int size)
311{
312 for(int i=0; i<size; i++)
313 {
314 if(shapeT[i].live && shapeT[i].collidingT == false)
315 {
316
317
318 al_draw_triangle(shapeT[i].pos_x1-8,shapeT[i].pos_y1 + 10,shapeT[i].pos_x1,shapeT[i].pos_y1-10,
319 shapeT[i].pos_x1+8,shapeT[i].pos_y1+10,al_map_rgb(255,0,255),2);
320
321
322 }
323 }
324}
325
326void StartTriangle(Triangle shapeT[], int size)
327{
328 for (int i = 0 ; i < size; i++)
329 {
330 if(!shapeT[i].live)
331 {
332 if(rand() % 400 == 0)
333 {
334 if(time_remaining % 2 == 0 && time_remaining % 25 != 0)
335 {
336 shapeT[i].live = true;
337 shapeT[i].pos_x1 = WIDTH;
338 shapeT[i].pos_y1 = HEIGHT-10;
339
340 break;
341 }
342 }
343 }
344 }
345}
346
347void UpdateTriangle(Triangle shapeT[], int size, Ball &shapeB)
348{
349 for(int i=0; i<size; i++)
350 {
351 if((shapeT[i].live) && shapeT[i].collidingT == false)
352 {
353 shapeT[i].pos_x1 -= speed;
354
355
356
357 if(shapeT[i].pos_x1-15 < 0)
358 {
359 shapeT[i].live = false;
360 shapeB.score++;
361 }
362 }
363 }
364}
365
366void CollideTriangle(Triangle shapeT[], Square shapeS[], int csize, Ball &shapeB, Explosion &explosion)
367{
368 for(int i = 0; i < csize; i++)
369 {
370 if(shapeT[i].live)
371 {
372
373
374 if((shapeT[i].pos_x1 - shapeT[i].bound_triangle_x < shapeB.pos_X + shapeB.boundx)
375 && (shapeT[i].pos_x1 + shapeT[i].bound_triangle_x > shapeB.pos_X - shapeB.boundx)
376 &&(shapeT[i].pos_y1 - shapeT[i].bound_triangle_y < shapeB.pos_Y + shapeB.boundy)
377 &&(shapeT[i].pos_y1 + shapeT[i].bound_triangle_y > shapeB.pos_Y - shapeB.boundy))
378 {
379
380 shapeT[i].live = false;
381 shapeB.pos_Y = shapeT[i].pos_y1 - shapeT[i].bound_triangle_y - shapeB.boundy - 20;
382
383 StartExplosions(explosion,shapeB.pos_X, shapeB.pos_Y);
384 al_play_sample(boom, 1,0,1,ALLEGRO_PLAYMODE_ONCE,0);
385 shapeB.lives--;
386
387 }
388 /*if(time_remaining % 25 == 0)
389 {
390 if(shapeT[i].pos_x1 - shapeT[i].bound_triangle_x < shapeS[i].pos_rect_x1 + 40
391 && shapeT[i].pos_y1 - shapeT[i].bound_triangle_y < shapeS[i].pos_rect_y1+40
392 && shapeS[i].pos_rect_x1 < shapeT[i].pos_x1+shapeT[i].bound_triangle_x
393 && shapeS[i].pos_rect_y1 < shapeT[i].pos_y1+shapeT[i].bound_triangle_y)
394 {
395 shapeT[i].collidingT = true;
396
397 }
398
399 }*/
400
401
402
403
404
405
406
407
408 }
409 }
410
411}
412
413
414void InitSquare(Square shapeS[], int size)
415{
416 for(int i = 0; i < size ; i++)
417 {
418 shapeS[i].ID = SQUARE;
419 shapeS[i].live = false;
420 shapeS[i].collidingS = false;
421 }
422}
423void DrawSquare(Square shapeS[], int size)
424{
425 for(int i = 0; i<size; i++)
426 {
427 if(shapeS[i].live)
428 {
429 al_draw_rounded_rectangle(shapeS[i].pos_rect_x1,shapeS[i].pos_rect_y1,
430 shapeS[i].pos_rect_x1+40,shapeS[i].pos_rect_y1+40,6,6,al_map_rgb(255,255,255),2);
431 }
432 }
433}
434void StartSquare(Square shapeS[], int size)
435{
436 for (int i = 0 ; i < size; i++)
437 {
438 if(!shapeS[i].live)
439 {
440 if(rand() % 100 == 0)
441 {
442 if((time_remaining % 25) == 0)
443 shapeS[i].live = true;
444 shapeS[i].pos_rect_x1 = WIDTH+40;
445 shapeS[i].pos_rect_y1 = HEIGHT-40;
446
447 break;
448
449 }
450 }
451 }
452}
453void UpdateSquare(Square shapeS[], int size, Ball &shapeB)
454{
455 for(int i=0; i<size; i++)
456 {
457 if(shapeS[i].live)
458 {
459 shapeS[i].pos_rect_x1 -= speed;
460
461 if(shapeS[i].pos_rect_x1+40 <= 0)
462 {
463 shapeS[i].live = false;
464 shapeB.score++;
465 }
466 }
467 }
468}
469
470void CollideSquare(Square shapeS[], int ssize, Ball &shapeB, Explosion &explosion)
471{
472 for(int i=0; i < ssize ; i++)
473 {
474 if(shapeS[i].live)
475 {
476 if(((shapeS[i].pos_rect_x1 < shapeB.pos_X + shapeB.boundx +7)
477 &&(shapeS[i].pos_rect_x1+ 40 > shapeB.pos_X - shapeB.boundx))
478 &&!((shapeS[i].pos_rect_y1 < shapeB.pos_Y + shapeB.boundy)
479 &&(shapeS[i].pos_rect_y1+40 > shapeB.pos_Y - shapeB.boundy)))
480 {
481 shapeB.LeftCollision = false;
482 shapeB.pos_Y = shapeS[i].pos_rect_y1 - shapeB.boundy - 7 ;
483 shapeB.isOnSquare = true;
484 }
485
486 else if((shapeS[i].pos_rect_x1 < shapeB.pos_X + shapeB.boundx+ 7)
487 &&(shapeS[i].pos_rect_x1 > shapeB.pos_X - shapeB.boundx))
488 {
489 shapeB.LeftCollision = true;
490 }
491
492 else
493 {
494 shapeB.LeftCollision = false;
495
496 }
497 }
498 }
499}
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Steve Terry
Member #1,989
March 2002
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I still don't see anywhere where you are updating your x position. If you are on top of a square just keep your x position incrementing. ___________________________________ |
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varynoob
Member #14,058
February 2012
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The x position, increments by itself. i.e the Square keeps on scrolling towards left, while ball is in the same position during the gameplay! Also, the LeftCollision value does not get updated in the Update() section!! 1#include "GameObject.h"
2
3GameObject :: GameObject()
4{
5 x = 0;
6 y = 0;
7
8 velX = 0;
9 velY = 0;
10
11 dirX = 0;
12 dirY = 0;
13
14 boundX = 0;
15 boundY = 0;
16
17 LeftCollision = false;
18
19
20 maxFrame = 0;
21 curFrame = 0;
22 frameCount = 0;
23 frameDelay = 0;
24 frameWidth = 0;
25 frameHeight = 0;
26 animationColumns = 0;
27 animationDirection = 0;
28
29 image = NULL;
30
31 alive = true;
32 collidable = true;
33}
34
35void GameObject :: Destroy()
36{
37
38}
39
40void GameObject :: Init(float x, float y, float velX, float velY, int dirX, int dirY, int boundX, int boundY)
41{
42 GameObject :: x = x;
43 GameObject :: y = y;
44
45 GameObject :: velX = velX;
46 GameObject :: velY = velY;
47
48 GameObject :: dirX = dirX;
49 GameObject :: dirY = dirY;
50
51 GameObject :: boundX = boundX;
52 GameObject :: boundY = boundY;
53}
54void GameObject :: Update()
55{
56 if(LeftCollision == false) // Always remains false!! Inspite of it being updated to TRUE, below in the Check Collision section!!
57 {
58 x += velX * dirX;
59 y += velY * dirY;
60 }
61}
62void GameObject :: Render()
63{
64}
65
66bool GameObject :: CheckCollisions(GameObject *otherObject)
67{
68 float oX = otherObject->GetX();
69 float oY = otherObject->GetY();
70
71 int obX = otherObject->GetBoundX();
72 int obY = otherObject->GetBoundY();
73
74
75 if( x + boundX > oX - obX &&
76 x - boundX < oX + obX &&
77 y + boundY > oY - obY &&
78 y - boundY < oY + obY && otherObject->GetID() == TRIANGLE)
79 {
80 return true;
81 }
82 else if(((oX < x + boundX + 14)&&(oX+ 40 >x - boundX))&&!((oY < y + boundY)&&(oY+40 > y - boundY))
83 && otherObject->GetID() == SQUARE)
84 {
85 y = oY - boundX;
86 //x = oX + 40;
87 return true;
88 }
89 else if((oX < x + boundX + 14) && (oX > x - boundX) && otherObject->GetID() == SQUARE)
90 {
91 LeftCollision = true; //this becomes true, as and when condition is me
92 return false;
93 }
94 else
95 {
96 return false;
97 LeftCollision = false;
98 }
99}
100void GameObject :: Collided(int objectID)
101{
102
103}
104bool GameObject :: Collidable()
105{
106 return alive && collidable;
107}
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