| 87 | } |
| 88 | |
| 89 | void Blitter_8bppBase::ScrollBuffer(void *video, int &left, int &top, int &width, int &height, int scroll_x, int scroll_y) |
| 90 | { |
| 91 | const uint8_t *src; |
| 92 | uint8_t *dst; |
| 93 | |
| 94 | if (scroll_y > 0) { |
| 95 | /* Calculate pointers */ |
| 96 | dst = (uint8_t *)video + left + (top + height - 1) * _screen.pitch; |
| 97 | src = dst - scroll_y * _screen.pitch; |
| 98 | |
| 99 | /* Decrease height and increase top */ |
| 100 | top += scroll_y; |
| 101 | height -= scroll_y; |
| 102 | assert(height > 0); |
| 103 | |
| 104 | /* Adjust left & width */ |
| 105 | if (scroll_x >= 0) { |
| 106 | dst += scroll_x; |
| 107 | left += scroll_x; |
| 108 | width -= scroll_x; |
| 109 | } else { |
| 110 | src -= scroll_x; |
| 111 | width += scroll_x; |
| 112 | } |
| 113 | |
| 114 | Blitter::MovePixels(src, dst, width, height, -_screen.pitch); |
| 115 | } else { |
| 116 | /* Calculate pointers */ |
| 117 | dst = (uint8_t *)video + left + top * _screen.pitch; |
| 118 | src = dst - scroll_y * _screen.pitch; |
| 119 | |
| 120 | /* Decrease height. (scroll_y is <=0). */ |
| 121 | height += scroll_y; |
| 122 | assert(height > 0); |
| 123 | |
| 124 | /* Adjust left & width */ |
| 125 | if (scroll_x >= 0) { |
| 126 | dst += scroll_x; |
| 127 | left += scroll_x; |
| 128 | width -= scroll_x; |
| 129 | } else { |
| 130 | src -= scroll_x; |
| 131 | width += scroll_x; |
| 132 | } |
| 133 | |
| 134 | Blitter::MovePixels(src, dst, width, height, _screen.pitch); |
| 135 | } |
| 136 | } |
| 137 | |
| 138 | size_t Blitter_8bppBase::BufferSize(uint width, uint height) |
| 139 | { |