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| author | Juan J. Martinez <jjm@usebox.net> | 2023-05-10 20:51:15 +0100 |
|---|---|---|
| committer | Juan J. Martinez <jjm@usebox.net> | 2023-05-10 20:51:15 +0100 |
| commit | 710c64fc02390e41ec29667c7a0d32115bf313ec (patch) | |
| tree | 5af5f6c8e300b4ace82dcb9cd9d90a14c21426be | |
| parent | f15e55b960e1aa4d63c29f85d5db931342b617d9 (diff) | |
| download | tr8vm-710c64fc02390e41ec29667c7a0d32115bf313ec.tar.gz tr8vm-710c64fc02390e41ec29667c7a0d32115bf313ec.zip | |
Do clipping in the blitter
| -rw-r--r-- | tr8vm.c | 29 |
1 files changed, 15 insertions, 14 deletions
@@ -191,10 +191,9 @@ uint8_t port(uint8_t p, uint8_t v) if (v & 1) { uint16_t src = blt_param[0] | (blt_param[1] << 8); - uint16_t dst = VIDEO_RAM + blt_param[2] + blt_param[3] * TR8_W; - for (uint8_t y = 0; y < blt_param[5]; y++) - for (uint8_t x = 0; x < blt_param[4]; x++) + for (int16_t y = blt_param[3]; y < blt_param[3] + blt_param[5]; y++) + for (int16_t x = blt_param[2]; x < blt_param[2] + blt_param[4]; x++) { uint8_t b = read_m(src++); @@ -202,26 +201,28 @@ uint8_t port(uint8_t p, uint8_t v) if ((v & 2) && (b & 128)) continue; - write_m(dst + x + y * 128, b); + /* clipping */ + if (x < 0 || x >= TR8_W || y < 0 || y >= TR8_H) + continue; + + write_m((uint16_t)(VIDEO_RAM + x + y * 128), b); } } /* read from vram */ else { - uint16_t src = VIDEO_RAM + blt_param[2] + blt_param[3] * TR8_W; uint16_t dst = blt_param[0] | (blt_param[1] << 8); - for (uint8_t y = 0; y < blt_param[5]; y++) - for (uint8_t x = 0; x < blt_param[4]; x++) + for (int16_t y = blt_param[3]; y < blt_param[3] + blt_param[5]; y++) + for (int16_t x = blt_param[2]; x < blt_param[2] + blt_param[4]; x++) { - uint8_t b = read_m(src + x + y * 128); + uint8_t b = 0; - /* skip transparent if transparent flag is set */ - if ((v & 2) && (b & 128)) - { - dst++; - continue; - } + /* clipping */ + if (x >= 0 && x < TR8_W && y >= 0 && y < TR8_H) + /* skip transparent if transparent flag is set */ + if (!((v & 2) && (b & 128))) + b = read_m(VIDEO_RAM + x + y * 128); write_m(dst++, b); } |