3 files changed, 43 insertions, 23 deletions

diff --git a/src/mesa/state_tracker/st_cb_feedback.c b/src/mesa/state_tracker/st_cb_feedback.c
index 5e334e3c857..923e1cdb893 100644
--- a/src/mesa/state_tracker/st_cb_feedback.c
+++ b/src/mesa/state_tracker/st_cb_feedback.c
@@ -93,8 +93,9 @@ feedback_vertex(GLcontext *ctx, const struct draw_context *draw,
    const GLfloat ci = 0;
    GLuint slot;
 
+   /* Recall that Y=0=Top of window for Gallium wincoords */
    win[0] = v->data[0][0];
-   win[1] = v->data[0][1];
+   win[1] = ctx->DrawBuffer->Height - v->data[0][1];
    win[2] = v->data[0][2];
    win[3] = 1.0F / v->data[0][3];
 
@@ -104,13 +105,13 @@ feedback_vertex(GLcontext *ctx, const struct draw_context *draw,
     */
 
    slot = st->vertex_result_to_slot[VERT_RESULT_COL0];
-   if (slot)
+   if (slot != ~0)
       color = v->data[slot];
    else
       color = ctx->Current.Attrib[VERT_ATTRIB_COLOR0];
 
    slot = st->vertex_result_to_slot[VERT_RESULT_TEX0];
-   if (slot)
+   if (slot != ~0)
       texcoord = v->data[slot];
    else
       texcoord = ctx->Current.Attrib[VERT_ATTRIB_TEX0];
@@ -294,13 +295,6 @@ st_RenderMode(GLcontext *ctx, GLenum newMode )
       draw_set_rasterize_stage(draw, st->selection_stage);
       /* Plug in new vbo draw function */
       vbo->draw_prims = st_feedback_draw_vbo;
-      /* setup post-transform vertex attribs */
-      {
-         /* just emit pos as GLfloat[4] */
-         static const uint attrs[1] = { FORMAT_4F };
-         const interp_mode *interp = NULL;
-         draw_set_vertex_attributes(draw, attrs, interp, 1);
-      }
    }
    else {
       if (!st->feedback_stage)
@@ -308,19 +302,8 @@ st_RenderMode(GLcontext *ctx, GLenum newMode )
       draw_set_rasterize_stage(draw, st->feedback_stage);
       /* Plug in new vbo draw function */
       vbo->draw_prims = st_feedback_draw_vbo;
-      /* setup post-transform vertex attribs */
-      {
-         /* emit all attribs as GLfloat[4] */
-         uint attrs[PIPE_MAX_SHADER_OUTPUTS];
-         interp_mode interp[PIPE_MAX_SHADER_OUTPUTS];
-         GLuint n = st->state.vs->state.num_outputs;
-         GLuint i;
-         for (i = 0; i < n; i++) {
-            attrs[i] = FORMAT_4F;
-            interp[i] = INTERP_NONE;
-         }
-         draw_set_vertex_attributes(draw, attrs, interp, n);
-      }
+      /* need to generate/use a vertex program that emits pos/color/tex */
+      st->dirty.st |= ST_NEW_VERTEX_PROGRAM;
    }
 }
 
diff --git a/src/mesa/state_tracker/st_draw.c b/src/mesa/state_tracker/st_draw.c
index 7fcc4d8e65f..1806a1888ba 100644
--- a/src/mesa/state_tracker/st_draw.c
+++ b/src/mesa/state_tracker/st_draw.c
@@ -310,6 +310,35 @@ st_draw_vertices(GLcontext *ctx, unsigned prim,
 }
 
 
+/**
+ * Set the (private) draw module's post-transformed vertex format when in
+ * GL_SELECT or GL_FEEDBACK mode.
+ */
+static void
+set_feedback_vertex_format(GLcontext *ctx)
+{
+   struct st_context *st = ctx->st;
+   uint attrs[PIPE_MAX_SHADER_OUTPUTS];
+   interp_mode interp[PIPE_MAX_SHADER_OUTPUTS];
+   GLuint n, i;
+
+   if (ctx->RenderMode == GL_FEEDBACK) {
+      /* emit all attribs (pos, color, texcoord) as GLfloat[4] */
+      n = st->state.vs->state.num_outputs;
+      for (i = 0; i < n; i++) {
+         attrs[i] = FORMAT_4F;
+         interp[i] = INTERP_NONE;
+      }
+   }
+   else {
+      assert(ctx->RenderMode == GL_SELECT);
+      n = 1;
+      attrs[0] = FORMAT_4F;
+      interp[0] = INTERP_NONE;
+   }
+
+   draw_set_vertex_attributes(st->draw, attrs, interp, n);
+}
 
 
 /**
@@ -359,6 +388,7 @@ st_feedback_draw_vbo(GLcontext *ctx,
    draw_set_clip_state(draw, &st->state.clip);
    draw_set_rasterizer_state(draw, &st->state.rasterizer->state);
    draw_bind_vertex_shader(draw, st->state.vs->data);
+   set_feedback_vertex_format(ctx);
 
    /* loop over TGSI shader inputs to determine vertex buffer
     * and attribute info
diff --git a/src/mesa/tnl/t_vp_build.c b/src/mesa/tnl/t_vp_build.c
index b28102b1b91..a588b0d16b0 100644
--- a/src/mesa/tnl/t_vp_build.c
+++ b/src/mesa/tnl/t_vp_build.c
@@ -134,6 +134,13 @@ static struct state_key *make_state_key( GLcontext *ctx )
    assert(fp);
 
    key->fragprog_inputs_read = fp->Base.InputsRead;
+   if (ctx->RenderMode == GL_FEEDBACK) {
+      /* This is a bit of a hack, but you can imagine feedback mode as using
+       * a special no-op fragment shader that just requires particular
+       * inputs (inputs which satisfy feedback mode).
+       */
+      key->fragprog_inputs_read |= FRAG_BIT_COL0 | FRAG_BIT_TEX0;
+   }
 
    key->separate_specular = (ctx->Light.Model.ColorControl ==
 			     GL_SEPARATE_SPECULAR_COLOR);