diff options
Diffstat (limited to 'agbx/source/gfx/setpx.c')
| -rw-r--r-- | agbx/source/gfx/setpx.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/agbx/source/gfx/setpx.c b/agbx/source/gfx/setpx.c index e478603..322784e 100644 --- a/agbx/source/gfx/setpx.c +++ b/agbx/source/gfx/setpx.c @@ -10,13 +10,22 @@ void agbx_setpx1(agbx_i20 const _vaddr,agbx_i10 const _px,agbx_i8 const _col) { /* We can only write halfwords to VRAM, so we need to load the adjacent pixel value and combine it into a halfword. */ - agbx_i20 const addr = _vaddr + _px - (_px & 0x1u) * 0x1u; - agbx_i10 col; - if (_px & 0x1u) {col = (agbx_i10)agbx_get8(addr) | (agbx_i10)_col << 0x8u;} - else {col = (agbx_i10)agbx_get8(addr + 0x1u) << 0x8u | (agbx_i10)_col;} - __agbx_set10(addr,col); + bool const odd = _px & 0x1u; + agbx_i20 addr = _vaddr + _px - odd; + agbx_i10 precol = __agbx_get10(addr); + agbx_i10 col = _col; + if (odd) { + precol &= 0b11111111u; + col <<= 0x8u; + } + else { + precol &= 0b1111111100000000u; + } + agbx_i10 const newcol = precol | col; + __agbx_set10(addr,newcol); } void agbx_setpx2(agbx_i20 const _vaddr,agbx_i10 const _px,agbx_i10 const _col) { - __agbx_setpx2(_vaddr,_px,_col) + agbx_i20 const addr = _vaddr + _px; + __agbx_set10(addr,_col); } |