tgsi/ureg: make the dst register match the src indirection

[mesa.git] / src / gallium / auxiliary / draw / draw_pipe_clip.c

diff --git a/src/gallium/auxiliary/draw/draw_pipe_clip.c b/src/gallium/auxiliary/draw/draw_pipe_clip.c
index 7b879c4cd50239c0e7ca6cb37a6ec4860731b168..8da0c41390fd2269dcf8139b197e9a74104c61ea 100644 (file)
--- a/src/gallium/auxiliary/draw/draw_pipe_clip.c
+++ b/src/gallium/auxiliary/draw/draw_pipe_clip.c
@@ -40,6 +40,7 @@
 #include "draw_vs.h"
 #include "draw_pipe.h"
 #include "draw_fs.h"
+#include "draw_gs.h"
 
 
 /** Set to 1 to enable printing of coords before/after clipping */
@@ -167,12 +168,17 @@ static void interp( const struct clip_stage *clip,
    {
       int k;
       t_nopersp = t;
-      for (k = 0; k < 2; k++)
+      /* find either in.x != out.x or in.y != out.y */
+      for (k = 0; k < 2; k++) {
          if (in->clip[k] != out->clip[k]) {
-            t_nopersp = (dst->clip[k] - out->clip[k]) /
-               (in->clip[k] - out->clip[k]);
+            /* do divide by W, then compute linear interpolation factor */
+            float in_coord = in->clip[k] / in->clip[3];
+            float out_coord = out->clip[k] / out->clip[3];
+            float dst_coord = dst->clip[k] / dst->clip[3];
+            t_nopersp = (dst_coord - out_coord) / (in_coord - out_coord);
             break;
          }
+      }
    }
 
    /* Other attributes
@@ -591,8 +597,10 @@ clip_init_state( struct draw_stage *stage )
 {
    struct clip_stage *clipper = clip_stage( stage );
    const struct draw_vertex_shader *vs = stage->draw->vs.vertex_shader;
+   const struct draw_geometry_shader *gs = stage->draw->gs.geometry_shader;
    const struct draw_fragment_shader *fs = stage->draw->fs.fragment_shader;
    uint i;
+   const struct tgsi_shader_info *vs_info = gs ? &gs->info : &vs->info;
 
    /* We need to know for each attribute what kind of interpolation is
     * done on it (flat, smooth or noperspective).  But the information
@@ -635,16 +643,16 @@ clip_init_state( struct draw_stage *stage )
 
    clipper->num_flat_attribs = 0;
    memset(clipper->noperspective_attribs, 0, sizeof(clipper->noperspective_attribs));
-   for (i = 0; i < vs->info.num_outputs; i++) {
+   for (i = 0; i < vs_info->num_outputs; i++) {
       /* Find the interpolation mode for a specific attribute
        */
       int interp;
 
       /* If it's gl_{Front,Back}{,Secondary}Color, pick up the mode
        * from the array we've filled before. */
-      if (vs->info.output_semantic_name[i] == TGSI_SEMANTIC_COLOR ||
-          vs->info.output_semantic_name[i] == TGSI_SEMANTIC_BCOLOR) {
-         interp = indexed_interp[vs->info.output_semantic_index[i]];
+      if (vs_info->output_semantic_name[i] == TGSI_SEMANTIC_COLOR ||
+          vs_info->output_semantic_name[i] == TGSI_SEMANTIC_BCOLOR) {
+         interp = indexed_interp[vs_info->output_semantic_index[i]];
       } else {
          /* Otherwise, search in the FS inputs, with a decent default
           * if we don't find it.
@@ -653,8 +661,8 @@ clip_init_state( struct draw_stage *stage )
          interp = TGSI_INTERPOLATE_PERSPECTIVE;
          if (fs) {
             for (j = 0; j < fs->info.num_inputs; j++) {
-               if (vs->info.output_semantic_name[i] == fs->info.input_semantic_name[j] &&
-                   vs->info.output_semantic_index[i] == fs->info.input_semantic_index[j]) {
+               if (vs_info->output_semantic_name[i] == fs->info.input_semantic_name[j] &&
+                   vs_info->output_semantic_index[i] == fs->info.input_semantic_index[j]) {
                   interp = fs->info.input_interpolate[j];
                   break;
                }