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(svn r21768) -Fix [FS#4396]: Diagonal tile iterator needed a special case for A * 0 selections.
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@ -139,26 +139,38 @@ TileIterator &DiagonalTileIterator::operator++()
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{
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{
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assert(this->tile != INVALID_TILE);
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assert(this->tile != INVALID_TILE);
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/* Determine the next tile, while clipping at map borders */
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bool new_line = false;
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bool new_line = false;
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do {
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do {
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/* Iterate using the rotated coordinates. */
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/* Iterate using the rotated coordinates. */
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if (this->a_max > 0) {
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if (this->a_max == 1 || this->a_max == -1) {
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this->a_cur += 2;
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/* Special case: Every second column has zero length, skip them completely */
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new_line = this->a_cur >= this->a_max;
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this->a_cur = 0;
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} else {
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this->a_cur -= 2;
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new_line = this->a_cur <= this->a_max;
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}
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if (new_line) {
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/* offset of initial a_cur: one tile in the same direction as a_max
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* every second line.
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*/
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this->a_cur = abs(this->a_cur) % 2 ? 0 : (this->a_max > 0 ? 1 : -1);
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if (this->b_max > 0) {
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if (this->b_max > 0) {
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++this->b_cur;
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this->b_cur = min(this->b_cur + 2, this->b_max);
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} else {
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} else {
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--this->b_cur;
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this->b_cur = max(this->b_cur - 2, this->b_max);
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}
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} else {
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/* Every column has at least one tile to process */
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if (this->a_max > 0) {
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this->a_cur += 2;
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new_line = this->a_cur >= this->a_max;
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} else {
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this->a_cur -= 2;
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new_line = this->a_cur <= this->a_max;
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}
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if (new_line) {
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/* offset of initial a_cur: one tile in the same direction as a_max
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* every second line.
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*/
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this->a_cur = abs(this->a_cur) % 2 ? 0 : (this->a_max > 0 ? 1 : -1);
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if (this->b_max > 0) {
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++this->b_cur;
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} else {
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--this->b_cur;
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}
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}
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}
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}
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}
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