gallium/radeon: fix Nine with its slightly shifted viewports

just need to do the calculation in floating-point and then round things
properly

Reviewed-by: Axel Davy <axel.davy@ens.fr>

diff --git a/src/gallium/drivers/radeon/r600_viewport.c b/src/gallium/drivers/radeon/r600_viewport.c
index 980c5ef17e652620b342015aed03ea20626a25b0..5c998c8c435b6fc01910e58b237aec1abe35e879 100644 (file)
--- a/src/gallium/drivers/radeon/r600_viewport.c
+++ b/src/gallium/drivers/radeon/r600_viewport.c
@@ -51,32 +51,38 @@ static void r600_get_scissor_from_viewport(struct r600_common_context *rctx,
                                           const struct pipe_viewport_state *vp,
                                           struct r600_signed_scissor *scissor)
 {
-       int tmp;
+       float tmp, minx, miny, maxx, maxy;
 
        /* Convert (-1, -1) and (1, 1) from clip space into window space. */
-       scissor->minx = -vp->scale[0] + vp->translate[0];
-       scissor->miny = -vp->scale[1] + vp->translate[1];
-       scissor->maxx = vp->scale[0] + vp->translate[0];
-       scissor->maxy = vp->scale[1] + vp->translate[1];
+       minx = -vp->scale[0] + vp->translate[0];
+       miny = -vp->scale[1] + vp->translate[1];
+       maxx = vp->scale[0] + vp->translate[0];
+       maxy = vp->scale[1] + vp->translate[1];
 
        /* r600_draw_rectangle sets this. Disable the scissor. */
-       if (scissor->minx == -1 && scissor->miny == -1 &&
-           scissor->maxx == 1 && scissor->maxy == 1) {
+       if (minx == -1 && miny == -1 && maxx == 1 && maxy == 1) {
                scissor->minx = scissor->miny = 0;
                scissor->maxx = scissor->maxy = GET_MAX_SCISSOR(rctx);
+               return;
        }
 
        /* Handle inverted viewports. */
-       if (scissor->minx > scissor->maxx) {
-               tmp = scissor->minx;
-               scissor->minx = scissor->maxx;
-               scissor->maxx = tmp;
+       if (minx > maxx) {
+               tmp = minx;
+               minx = maxx;
+               maxx = tmp;
        }
-       if (scissor->miny > scissor->maxy) {
-               tmp = scissor->miny;
-               scissor->miny = scissor->maxy;
-               scissor->maxy = tmp;
+       if (miny > maxy) {
+               tmp = miny;
+               miny = maxy;
+               maxy = tmp;
        }
+
+       /* Convert to integer and round up the max bounds. */
+       scissor->minx = minx;
+       scissor->miny = miny;
+       scissor->maxx = ceilf(maxx);
+       scissor->maxy = ceilf(maxy);
 }
 
 static void r600_clamp_scissor(struct r600_common_context *rctx,