diff options
Diffstat (limited to 'src/mesa/pipe')
| -rw-r--r-- | src/mesa/pipe/draw/draw_wide_prims.c | 55 |
1 files changed, 47 insertions, 8 deletions
diff --git a/src/mesa/pipe/draw/draw_wide_prims.c b/src/mesa/pipe/draw/draw_wide_prims.c index e61cc2e025..76b8a5319b 100644 --- a/src/mesa/pipe/draw/draw_wide_prims.c +++ b/src/mesa/pipe/draw/draw_wide_prims.c @@ -100,17 +100,56 @@ static void wide_line( struct draw_stage *stage, const float dx = FABSF(pos0[0] - pos2[0]); const float dy = FABSF(pos0[1] - pos2[1]); + /* + * Draw wide line as a quad (two tris) by "stretching" the line along + * X or Y. + * XXX For AA lines, the quad corners have to be computed in a + * more sophisticated way. + */ + + /* need to tweak coords in several ways to be conformant here */ + if (dx > dy) { - pos0[1] -= half_width; - pos1[1] += half_width; - pos2[1] -= half_width; - pos3[1] += half_width; + /* x-major line */ + pos0[1] = pos0[1] - half_width - 0.25; + pos1[1] = pos1[1] + half_width - 0.25; + pos2[1] = pos2[1] - half_width - 0.25; + pos3[1] = pos3[1] + half_width - 0.25; + if (pos0[0] < pos2[0]) { + /* left to right line */ + pos0[0] -= 0.5; + pos1[0] -= 0.5; + pos2[0] -= 0.5; + pos3[0] -= 0.5; + } + else { + /* right to left line */ + pos0[0] += 0.5; + pos1[0] += 0.5; + pos2[0] += 0.5; + pos3[0] += 0.5; + } } else { - pos0[0] -= half_width; - pos1[0] += half_width; - pos2[0] -= half_width; - pos3[0] += half_width; + /* y-major line */ + pos0[0] = pos0[0] - half_width + 0.25; + pos1[0] = pos1[0] + half_width + 0.25; + pos2[0] = pos2[0] - half_width + 0.25; + pos3[0] = pos3[0] + half_width + 0.25; + if (pos0[1] < pos2[1]) { + /* top to bottom line */ + pos0[1] -= 0.5; + pos1[1] -= 0.5; + pos2[1] -= 0.5; + pos3[1] -= 0.5; + } + else { + /* bottom to top line */ + pos0[1] += 0.5; + pos1[1] += 0.5; + pos2[1] += 0.5; + pos3[1] += 0.5; + } } tri.det = header->det; /* only the sign matters */ |