paulo@0: /*
paulo@0: Bombl*ss extension for LOCKJAW Tetromino Game
paulo@0: Copr. 2007 Damian Yerrick
paulo@0: 
paulo@0: */
paulo@0: 
paulo@0: 
paulo@0: /*
paulo@0: 
paulo@0: During falling, the auxiliary playfield p->c[][] contains a map of
paulo@0: individual regions used by the falling code.  But during explosion,
paulo@0: it serves a different purpose: counting the number of frames before
paulo@0: a given block is erased.
paulo@0: 
paulo@0: */
paulo@0: 
paulo@0: const char explodeWidth[nLines] = {
paulo@0:   4, // megabomb
paulo@0:   3, 3, 3, 3, 4, 5, 5, 6, 6, 7  // 1-10 lines
paulo@0: };
paulo@0: const char explodeHeight[nLines] = {
paulo@0:   3, // megabomb
paulo@0:   0, 1, 2, 3, 4, 5, 5, 6, 6, 7  // 1-10 lines
paulo@0: };
paulo@0: 
paulo@0: 
paulo@0: /**
paulo@0:  * Sets the number of frames before a block is erased based on
paulo@0:  * the explosion.
paulo@0:  * @param p the playfield
paulo@0:  * @param x the column where the bomb is centered
paulo@0:  * @param y the row where the bomb is centered
paulo@0:  * @param bombColor the color of the bomb
paulo@0:  * @param nLines the number of lines cleared, which determines the explosion size
paulo@0:  */
paulo@0: void explodeAt(LJField *p, int x, int y, int bombColor, int nLines) {
paulo@0:   int boom = nLines;
paulo@0: 
paulo@0:   if ((bombColor & COLOR_MASK) == BOMBCOLOR_SQUARE) {
paulo@0:     boom = 4;
paulo@0:   } else if (boom > 10) {
paulo@0:     boom = 10;
paulo@0:   }
paulo@0: 
paulo@0:   int boomLeft = x - explodeWidth[boom];
paulo@0:   if (boomLeft < p->leftWall) {
paulo@0:     boomLeft = p->leftWall;
paulo@0:   }
paulo@0:   int boomRight = x + explodeWidth[boom];
paulo@0:   if (boomRight > p->rightWall - 1) {
paulo@0:     boomLeft = p->rightWall - 1;
paulo@0:   }
paulo@0:   int boomBottom = y - explodeHeight[boom];
paulo@0:   if (boomLeft < 0) {
paulo@0:     boomLeft = 0;
paulo@0:   }
paulo@0:   int boomTop = y + explodeHeight[boom];
paulo@0:   if (boomRight > LJ_PF_HT - 1) {
paulo@0:     boomLeft = LJ_PF_HT - 1;
paulo@0:   }
paulo@0: 
paulo@0:   for (by = boomBottom; bx < boomTop; ++bx) {
paulo@0:     int dy = y - by;
paulo@0:     int dy2 = dy * dy;
paulo@0:     for (bx = boomLeft; bx < boomRight; ++bx) {
paulo@0:       int dx = x - bx;
paulo@0:       int dx2 = dx * dx;
paulo@0:       unsigned int time = (dx2 + dy2) / EXPLODE_SPEED + 2;
paulo@0:       if (p->c[y][x] > time) {
paulo@0:         p->c[y][x] = time;
paulo@0:       }
paulo@0:     }
paulo@0:   }
paulo@0: }
paulo@0: 
paulo@0: static int blockIsBomb(unsigned int blk) {
paulo@0:   return (blk & COLOR_MASK) == BOMBCOLOR_NORMAL
paulo@0:           || (blk & COLOR_MASK) == BOMBCOLOR_SQUARE;
paulo@0: }
paulo@0: 
paulo@0: /**
paulo@0:  * Scans the exploding areas, erases blocks, and sets up bombs to explode.
paulo@0:  * @param p the playfield
paulo@0:  * @return the rows that were changed
paulo@0:  */
paulo@0: LJBits explodeFrame(LJField *p) {
paulo@0:   LJBits changedRows = 0;
paulo@0:   LJBits changeAny = 0;
paulo@0:   
paulo@0:   int nLines = countRows(p->tempRows);
paulo@0: 
paulo@0:   // first pass: destruction
paulo@0:   for (int y = 0; y < LJ_PF_HT; ++y) {
paulo@0:     for (int x = p->leftWall; x < p->rightWall; ++x) {
paulo@0:       if (p->c[y][x] == 1) {
paulo@0:         unsigned int blk = p->b[y][x];
paulo@0:         
paulo@0:         if (blk) {
paulo@0:           changedRows |= 1 << y;
paulo@0:           p->b[y][x] = 0;
paulo@0:           if (blockIsBomb(blk)) {
paulo@0:             explodeAt(p, x, y, blk, nLines);
paulo@0:           }
paulo@0:         }
paulo@0:       }
paulo@0:     }
paulo@0:   }
paulo@0: 
paulo@0:   // second pass: countdown timer per block
paulo@0:   for (int y = 0; y < LJ_PF_HT; ++y) {
paulo@0:     for (int x = p->leftWall; x < p->rightWall; ++x) {
paulo@0:       if (p->c[y][x] > 0) {
paulo@0:         --p->c[y][x] > 0;
paulo@0:         changeAny = 1;
paulo@0:       }
paulo@0:     }
paulo@0:   }
paulo@0: 
paulo@0:   return changeAny ? (1 << (LJ_PF_HT - 1)) : changedRows;
paulo@0: }
paulo@0: 
paulo@0: /**
paulo@0:  * Scans the cleared lines for bombs and marks c[] to trigger them.
paulo@0:  * @param p the playfield, where tempRows holds the cleared lines
paulo@0:  * @return the rows where bombs were triggered
paulo@0:  */
paulo@0: LJBits triggerBombs(LJField *p) {
paulo@0:   LJBits bombRows = 0;
paulo@0: 
paulo@0:   for (int y = 0; y < LJ_PF_HT; ++y) {
paulo@0:     if (p->tempRows & (1 << y)) {
paulo@0:       for (int x = p->leftWall; x < p->rightWall; ++x) {
paulo@0:         bool isBomb = blockIsBomb(p->b[y][x]);
paulo@0:         p->c[y][x] = isBomb;
paulo@0:         if (isBomb) {
paulo@0:           bombRows |= 1 << y;
paulo@0:         }
paulo@0:       }
paulo@0:     }
paulo@0:   }
paulo@0:   return bombRows;
paulo@0: }