Brickmania: Revert to using intersection checks for testing if powerup hit

paddle

r24925 introduced a potential bug: the collision detection with the paddle is
not using the line intersection checks and consequently could cause the powerup
to be missed if the drop speed is fast enough (which varies depending on the
target because of the speed scaling).

Thanks for Karl Kurbjun for noticing and alerting!


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@24934 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 123 insertions, 110 deletions

diff --git a/apps/plugins/brickmania.c b/apps/plugins/brickmania.c
index dbc75bccf7..c95a88ac06 100644
--- a/apps/plugins/brickmania.c
+++ b/apps/plugins/brickmania.c
@@ -1533,6 +1533,13 @@ static int brickmania_game_loop(void)
             if (brick_on_board==0)
                 brick_on_board--;
 
+            /* Setup the pad line-later used in intersection test */
+            pad_line.p1.x = pad_pos_x;
+            pad_line.p1.y = PAD_POS_Y;
+
+            pad_line.p2.x = pad_pos_x + pad_width;
+            pad_line.p2.y = PAD_POS_Y;
+
             if (game_state!=ST_PAUSE)
             {
                 /* move the fires */
@@ -1568,7 +1575,8 @@ static int brickmania_game_loop(void)
                         }
                     }
                 }
-                /* move the powerups */
+
+                /* move and handle the powerups */
                 for (k=0;k<used_powers;k++)
                 {
                     int remove_power = 0;
@@ -1580,114 +1588,126 @@ static int brickmania_game_loop(void)
                         /* power hit bottom */
                         remove_power = 1;
                     }
-                    else if (power[k].top>PAD_POS_Y-POWERUP_HEIGHT &&
-                        power[k].x_pos>=pad_pos_x &&
-                        power[k].x_pos<pad_pos_x+pad_width)
+                    else
                     {
-                        /* power hit paddle */
-                        remove_power = 1;
-                        switch(power[k].type)
+                        /* Use misc_line to check if the center of the powerup
+                         *  hit the paddle.
+                         */
+                        misc_line.p1.x = power[k].x_pos;
+                        misc_line.p1.y = power[k].top;
+
+                        misc_line.p2 = misc_line.p1;
+                        misc_line.p2.y += SPEED_POWER;
+
+                        /* Check if the powerup will hit the paddle */
+                        if (check_lines(&misc_line, &pad_line, &pt_hit))
                         {
-                            case POWER_TYPE_LIFE_GAIN:
-                                life++;
-                                score += SCORE_POWER_LIFE_GAIN;
-                                break;
-                            case POWER_TYPE_LIFE_LOSS:
-                            life--;
-                                if (life>=0)
-                                {
-                                    brickmania_init_game(false);
-                                    brickmania_sleep(2);
-                                }
-                                break;
-                            case POWER_TYPE_PADDLE_STICKY:
-                                score += SCORE_POWER_PADDLE_STICKY;
-                                paddle_type = PADDLE_TYPE_STICKY;
-                                break;
-                            case POWER_TYPE_PADDLE_SHOOTER:
-                                score += SCORE_POWER_PADDLE_SHOOTER;
-                                paddle_type = PADDLE_TYPE_SHOOTER;
-                                for(i=0;i<used_balls;i++)
-                                    ball[i].glue=false;
-                                break;
-                            case POWER_TYPE_PADDLE_NORMAL:
-                                score += SCORE_POWER_PADDLE_NORMAL;
-                                paddle_type = PADDLE_TYPE_NORMAL;
-                                for(i=0;i<used_balls;i++)
-                                    ball[i].glue=false;
-                                flip_sides=false;
-                                pad_pos_x += (pad_width-PAD_WIDTH)/2;
-                                pad_width = PAD_WIDTH;
-                                break;
-                            case POWER_TYPE_PADDLE_FLIP:
-                                score += SCORE_POWER_FLIP;
-                                sec_count = *rb->current_tick+HZ;
-                                flip_sides_delay = FLIP_SIDES_DELAY;
-                                flip_sides = true;
-                                break;
-                            case POWER_TYPE_EXTRA_BALL:
-                                score += SCORE_POWER_EXTRA_BALL;
-                                if(used_balls<MAX_BALLS)
-                                {
-                                    /* Set the speed */
-                                    if(rb->rand()%2 == 0)
-                                        ball[used_balls].speedx=-SPEED_4Q_X;
-                                    else
-                                        ball[used_balls].speedx= SPEED_4Q_X;
-                                    ball[used_balls].speedy= SPEED_4Q_Y;
-                                    /* Ball is not glued */
-                                    ball[used_balls].glue= false;
-                                    used_balls++;
-                                }
-                                break;
-                            case POWER_TYPE_PADDLE_LONG:
-                                score+=SCORE_POWER_LONG_PADDLE;
-                                if (pad_width==PAD_WIDTH)
-                                {
-                                    pad_width = LONG_PAD_WIDTH;
-                                    pad_pos_x -= (LONG_PAD_WIDTH -
-                                                    PAD_WIDTH)/2;
-                                }
-                                else if (pad_width==SHORT_PAD_WIDTH)
-                                {
+
+                            /* power hit paddle */
+                            remove_power = 1;
+                            switch(power[k].type)
+                            {
+                                case POWER_TYPE_LIFE_GAIN:
+                                    life++;
+                                    score += SCORE_POWER_LIFE_GAIN;
+                                    break;
+                                case POWER_TYPE_LIFE_LOSS:
+                                    life--;
+                                    if (life>=0)
+                                    {
+                                        brickmania_init_game(false);
+                                        brickmania_sleep(2);
+                                    }
+                                    break;
+                                case POWER_TYPE_PADDLE_STICKY:
+                                    score += SCORE_POWER_PADDLE_STICKY;
+                                    paddle_type = PADDLE_TYPE_STICKY;
+                                    break;
+                                case POWER_TYPE_PADDLE_SHOOTER:
+                                    score += SCORE_POWER_PADDLE_SHOOTER;
+                                    paddle_type = PADDLE_TYPE_SHOOTER;
+                                    for(i=0;i<used_balls;i++)
+                                        ball[i].glue=false;
+                                    break;
+                                case POWER_TYPE_PADDLE_NORMAL:
+                                    score += SCORE_POWER_PADDLE_NORMAL;
+                                    paddle_type = PADDLE_TYPE_NORMAL;
+                                    for(i=0;i<used_balls;i++)
+                                        ball[i].glue=false;
+                                    flip_sides=false;
+                                    pad_pos_x += (pad_width-PAD_WIDTH)/2;
                                     pad_width = PAD_WIDTH;
-                                    pad_pos_x-=(PAD_WIDTH-
-                                                    SHORT_PAD_WIDTH)/2;
-                                }
-                                if (pad_pos_x < 0)
-                                    pad_pos_x = 0;
-                                else if(pad_pos_x + pad_width >
-                                                        GAMESCREEN_WIDTH)
-                                    pad_pos_x = GAMESCREEN_WIDTH-pad_width;
-                                break;
-                            case POWER_TYPE_PADDLE_SHORT:
-                                if (pad_width==PAD_WIDTH)
-                                {
-                                    pad_width=SHORT_PAD_WIDTH;
-                                    pad_pos_x+=(PAD_WIDTH-
-                                                    SHORT_PAD_WIDTH)/2;
-                                }
-                                else if (pad_width==LONG_PAD_WIDTH)
-                                {
-                                    pad_width=PAD_WIDTH;
-                                    pad_pos_x+=(LONG_PAD_WIDTH-PAD_WIDTH)/2;
-                                }
-                                break;
-                            default:
-                                break;
+                                    break;
+                                case POWER_TYPE_PADDLE_FLIP:
+                                    score += SCORE_POWER_FLIP;
+                                    sec_count = *rb->current_tick+HZ;
+                                    flip_sides_delay = FLIP_SIDES_DELAY;
+                                    flip_sides = true;
+                                    break;
+                                case POWER_TYPE_EXTRA_BALL:
+                                    score += SCORE_POWER_EXTRA_BALL;
+                                    if(used_balls<MAX_BALLS)
+                                    {
+                                        /* Set the speed */
+                                        if(rb->rand()%2 == 0)
+                                            ball[used_balls].speedx=-SPEED_4Q_X;
+                                        else
+                                            ball[used_balls].speedx= SPEED_4Q_X;
+                                        ball[used_balls].speedy= SPEED_4Q_Y;
+                                        /* Ball is not glued */
+                                        ball[used_balls].glue= false;
+                                        used_balls++;
+                                    }
+                                    break;
+                                case POWER_TYPE_PADDLE_LONG:
+                                    score+=SCORE_POWER_LONG_PADDLE;
+                                    if (pad_width==PAD_WIDTH)
+                                    {
+                                        pad_width = LONG_PAD_WIDTH;
+                                        pad_pos_x -= (LONG_PAD_WIDTH -
+                                                PAD_WIDTH)/2;
+                                    }
+                                    else if (pad_width==SHORT_PAD_WIDTH)
+                                    {
+                                        pad_width = PAD_WIDTH;
+                                        pad_pos_x-=(PAD_WIDTH-
+                                                SHORT_PAD_WIDTH)/2;
+                                    }
+                                    if (pad_pos_x < 0)
+                                        pad_pos_x = 0;
+                                    else if(pad_pos_x + pad_width >
+                                            GAMESCREEN_WIDTH)
+                                        pad_pos_x = GAMESCREEN_WIDTH-pad_width;
+                                    break;
+                                case POWER_TYPE_PADDLE_SHORT:
+                                    if (pad_width==PAD_WIDTH)
+                                    {
+                                        pad_width=SHORT_PAD_WIDTH;
+                                        pad_pos_x+=(PAD_WIDTH-
+                                                SHORT_PAD_WIDTH)/2;
+                                    }
+                                    else if (pad_width==LONG_PAD_WIDTH)
+                                    {
+                                        pad_width=PAD_WIDTH;
+                                        pad_pos_x+=(LONG_PAD_WIDTH-PAD_WIDTH)/2;
+                                    }
+                                    break;
+                                default:
+                                    break;
+                            }
                         }
-                    }
 
-                    if (remove_power)
-                    {
-                        used_powers--;
-                        if (k != used_powers)
+                        if (remove_power)
                         {
-                            power[k].top = power[used_powers].top;
-                            power[k].x_pos = power[used_powers].x_pos;
-                            power[k].type = power[used_powers].type;
+                            used_powers--;
+                            if (k != used_powers)
+                            {
+                                power[k].top = power[used_powers].top;
+                                power[k].x_pos = power[used_powers].x_pos;
+                                power[k].type = power[used_powers].type;
+                            }
+                            k--;
                         }
-                        k--;
                     }
                 }
             }
@@ -1711,14 +1731,7 @@ static int brickmania_game_loop(void)
                     INT3(POWERUP_HEIGHT));
             }
 
-            /* Setup the pad line-later used in intersection test */
-            pad_line.p1.x = pad_pos_x;
-            pad_line.p1.y = PAD_POS_Y;
-
-            pad_line.p2.x = pad_pos_x + pad_width;
-            pad_line.p2.y = PAD_POS_Y;
-
-            /* handle all of the bricks/powerups */
+            /* handle all of the bricks */
             for (i=0; i<NUM_BRICKS_ROWS; i++)
             {
                 for (j=0; j<NUM_BRICKS_COLS ;j++)