freedreno/a4xx: fake LINEAR_PIXEL varying support for u_blitter

Signed-off-by: Jonathan Marek <jonathan@marek.ca>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5582>

diff --git a/src/gallium/drivers/freedreno/a4xx/fd4_program.c b/src/gallium/drivers/freedreno/a4xx/fd4_program.c
index 1a9c43ab9f57d3bdfb2ae6942eea56f345d2a5b3..4e98be45999f5fa8f2f5b7e8200e2f65f000842d 100644 (file)
--- a/src/gallium/drivers/freedreno/a4xx/fd4_program.c
+++ b/src/gallium/drivers/freedreno/a4xx/fd4_program.c
@@ -164,7 +164,7 @@ fd4_program_emit(struct fd_ringbuffer *ring, struct fd4_emit *emit,
 {
        struct stage s[MAX_STAGES];
        uint32_t pos_regid, posz_regid, psize_regid, color_regid[8];
-       uint32_t face_regid, coord_regid, zwcoord_regid, vcoord_regid;
+       uint32_t face_regid, coord_regid, zwcoord_regid, vcoord_regid, lcoord_regid;
        enum a3xx_threadsize fssz;
        int constmode;
        int i, j;
@@ -210,6 +210,16 @@ fd4_program_emit(struct fd_ringbuffer *ring, struct fd4_emit *emit,
        coord_regid     = ir3_find_sysval_regid(s[FS].v, SYSTEM_VALUE_FRAG_COORD);
        zwcoord_regid   = (coord_regid == regid(63,0)) ? regid(63,0) : (coord_regid + 2);
        vcoord_regid    = ir3_find_sysval_regid(s[FS].v, SYSTEM_VALUE_BARYCENTRIC_PERSP_PIXEL);
+       lcoord_regid    = ir3_find_sysval_regid(s[FS].v, SYSTEM_VALUE_BARYCENTRIC_LINEAR_PIXEL);
+
+       /* XXX since we don't know how to support noperspective varyings on a4xx,
+        * use this little hack to support u_blitter, which should be the only
+        * case with noperspective varyings on a4xx:
+        */
+       if (VALIDREG(lcoord_regid)) {
+               assert(!VALIDREG(vcoord_regid));
+               vcoord_regid = lcoord_regid;
+       }
 
        /* we could probably divide this up into things that need to be
         * emitted if frag-prog is dirty vs if vert-prog is dirty..