Mesa (arb_geometry_shader4): gs: start on fixing fetching of geometry shader inputs

[Zack Rusin]

Module: Mesa
Branch: arb_geometry_shader4
Commit: adf1d0cffcbababa0e4e968b5a916b27199b6dbb
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=adf1d0cffcbababa0e4e968b5a916b27199b6dbb

Author: Zack Rusin <zackr at vmware.com>
Date:   Thu Jul 16 20:39:46 2009 -0400

gs: start on fixing fetching of geometry shader inputs

it's a little wonky, because for geometry shaders some inputs match
vertex shader outputs and some are auto-generated (e.g. gl_VerticesIn or
gl_PrimitiveId) so we need to add those auto-generated ones to the
output stream of the vertex shader.

---

 src/gallium/auxiliary/draw/draw_gs.c |   75 ++++++++++++++++++++--------------
 1 files changed, 44 insertions(+), 31 deletions(-)

diff --git a/src/gallium/auxiliary/draw/draw_gs.c b/src/gallium/auxiliary/draw/draw_gs.c
index bdef375..a09bd2b 100644
--- a/src/gallium/auxiliary/draw/draw_gs.c
+++ b/src/gallium/auxiliary/draw/draw_gs.c
@@ -140,6 +140,48 @@ static INLINE int num_vertices_for_prim(int prim)
    }
 }
 
+static void draw_fetch_geometry_input(struct draw_geometry_shader *shader,
+                                      int start_primitive,
+                                      int num_primitives,
+                                      const float (*input)[4],
+                                      unsigned input_stride)
+{
+   struct tgsi_exec_machine *machine = shader->machine;
+   unsigned slot, k, j;
+   unsigned num_vertices = num_vertices_for_prim(shader->state.input_type);
+
+   for (k = 0; k < num_primitives; ++k) {
+      for (j = 0; j < num_vertices; j++) {
+         int idx = ((start_primitive + k) * num_vertices + j) * shader->info.num_inputs;
+#if 1
+         debug_printf("%d) Prim, %d) Input vert:\n", start_primitive, idx);
+         for (slot = 0; slot < shader->info.num_inputs; slot++) {
+            debug_printf("\t%d: %f %f %f %f\n", slot,
+                         input[idx + slot][0],
+                         input[idx + slot][1],
+                         input[idx + slot][2],
+                         input[idx + slot][3]);
+         }
+#endif
+
+         for (slot = 0; slot < shader->info.num_inputs; slot++) {
+#if 0
+            assert(!util_is_inf_or_nan(input[idx + slot][0]));
+            assert(!util_is_inf_or_nan(input[idx + slot][1]));
+            assert(!util_is_inf_or_nan(input[idx + slot][2]));
+            assert(!util_is_inf_or_nan(input[idx + slot][3]));
+#endif
+            machine->Inputs[idx + slot].xyzw[0].f[j] = input[idx + slot][0];
+            machine->Inputs[idx + slot].xyzw[1].f[j] = input[idx + slot][1];
+            machine->Inputs[idx + slot].xyzw[2].f[j] = input[idx + slot][2];
+            machine->Inputs[idx + slot].xyzw[3].f[j] = input[idx + slot][3];
+         }
+
+         input = (const float (*)[4])((const char *)input + input_stride);
+      }
+   }
+}
+
 void draw_geometry_shader_run(struct draw_geometry_shader *shader,
                               const float (*input)[4],
                               float (*output)[4],
@@ -149,7 +191,7 @@ void draw_geometry_shader_run(struct draw_geometry_shader *shader,
                               unsigned output_stride)
 {
    struct tgsi_exec_machine *machine = shader->machine;
-   unsigned int i, j, k;
+   unsigned int i, j;
    unsigned slot;
    unsigned num_vertices = num_vertices_for_prim(shader->state.input_type);
    unsigned num_primitives = count/num_vertices;
@@ -159,36 +201,7 @@ void draw_geometry_shader_run(struct draw_geometry_shader *shader,
    for (i = 0; i < num_primitives; i += MAX_TGSI_PRIMITIVES) {
       unsigned int max_primitives = MIN2(MAX_TGSI_PRIMITIVES, num_primitives - i);
 
-      for (k = 0; k < max_primitives; ++k) {
-         for (j = 0; j < num_vertices; j++) {
-            int idx = ((i + k) * num_vertices + j) * shader->info.num_inputs;
-#if 1
-            debug_printf("%d) Prim, %d) Input vert:\n", i, idx);
-            for (slot = 0; slot < shader->info.num_inputs; slot++) {
-               debug_printf("\t%d: %f %f %f %f\n", slot,
-                            input[idx + slot][0],
-                            input[idx + slot][1],
-                            input[idx + slot][2],
-                            input[idx + slot][3]);
-            }
-#endif
-
-            for (slot = 0; slot < shader->info.num_inputs; slot++) {
-#if 0
-               assert(!util_is_inf_or_nan(input[idx + slot][0]));
-               assert(!util_is_inf_or_nan(input[idx + slot][1]));
-               assert(!util_is_inf_or_nan(input[idx + slot][2]));
-               assert(!util_is_inf_or_nan(input[idx + slot][3]));
-#endif
-               machine->Inputs[idx + slot].xyzw[0].f[j] = input[idx + slot][0];
-               machine->Inputs[idx + slot].xyzw[1].f[j] = input[idx + slot][1];
-               machine->Inputs[idx + slot].xyzw[2].f[j] = input[idx + slot][2];
-               machine->Inputs[idx + slot].xyzw[3].f[j] = input[idx + slot][3];
-            }
-
-            input = (const float (*)[4])((const char *)input + input_stride);
-         }
-      }
+      draw_fetch_geometry_input(shader, i, max_primitives, input, input_stride);
 
       tgsi_set_exec_mask(machine,
                          1,