From 06472ad7e835813ef7c9bf8a5cd8b62a25fa9cc3 Mon Sep 17 00:00:00 2001 From: José Fonseca Date: Wed, 6 Oct 2010 09:40:51 +0100 Subject: llvmpipe: Fix sprite coord perspective interpolation of Q. Q coordinate's coefficients also need to be multiplied by w, otherwise it will have 1/w, causing problems with TXP. --- src/gallium/drivers/llvmpipe/lp_setup_point.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) (limited to 'src/gallium/drivers') diff --git a/src/gallium/drivers/llvmpipe/lp_setup_point.c b/src/gallium/drivers/llvmpipe/lp_setup_point.c index c91e85f9159..1295aeecd87 100644 --- a/src/gallium/drivers/llvmpipe/lp_setup_point.c +++ b/src/gallium/drivers/llvmpipe/lp_setup_point.c @@ -105,6 +105,8 @@ texcoord_coef(struct lp_setup_context *setup, unsigned sprite_coord_origin, boolean perspective) { + float w0 = info->v0[0][3]; + assert(i < 4); if (i == 0) { @@ -118,13 +120,6 @@ texcoord_coef(struct lp_setup_context *setup, point->inputs.a0[slot][0] = 0.5 - (dadx * x0 + dady * y0); if (perspective) { - /* Divide coefficients by vertex.w here. - * - * It would be clearer to always multiply by w0 above and - * then divide it out for perspective projection here, but - * doing it this way involves less algebra. - */ - float w0 = info->v0[0][3]; point->inputs.dadx[slot][0] *= w0; point->inputs.dady[slot][0] *= w0; point->inputs.a0[slot][0] *= w0; @@ -145,7 +140,6 @@ texcoord_coef(struct lp_setup_context *setup, point->inputs.a0[slot][1] = 0.5 - (dadx * x0 + dady * y0); if (perspective) { - float w0 = info->v0[0][3]; point->inputs.dadx[slot][1] *= w0; point->inputs.dady[slot][1] *= w0; point->inputs.a0[slot][1] *= w0; @@ -157,7 +151,7 @@ texcoord_coef(struct lp_setup_context *setup, point->inputs.dady[slot][2] = 0.0f; } else { - point->inputs.a0[slot][3] = 1.0f; + point->inputs.a0[slot][3] = perspective ? w0 : 1.0f; point->inputs.dadx[slot][3] = 0.0f; point->inputs.dady[slot][3] = 0.0f; } -- cgit v1.2.3