tgsi: add properties for fragment coord conventions (v3)

Changes in v3:
- Documented the new properties
- Added comments for property values
- Rebased to current master

Changes in v2:
- Caps are added in a separate, subsequent patch

This adds two TGSI fragment program properties that indicate the
fragment coord conventions.

The properties behave as described in the extension spec for
GL_ARB_fragment_coord_conventions, but the default origin in
upper left instead of lower left as in OpenGL.

The syntax is:
PROPERTY FS_COORD_ORIGIN [UPPER_LEFT|LOWER_LEFT]
PROPERTY FS_COORD_PIXEL_CENTER [HALF_INTEGER|INTEGER]

The names have been chosen for consistency with the GS properties
and the OpenGL extension spec.

The defaults are of course the previously assumed conventions:
UPPER_LEFT and HALF_INTEGER.

1 files changed, 32 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/tgsi/tgsi_ureg.c b/src/gallium/auxiliary/tgsi/tgsi_ureg.c
index f2610d0764..0ae46785bb 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_ureg.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_ureg.c
@@ -142,6 +142,8 @@ struct ureg_program
    unsigned property_gs_input_prim;
    unsigned property_gs_output_prim;
    unsigned property_gs_max_vertices;
+   unsigned char property_fs_coord_origin; /* = TGSI_FS_COORD_ORIGIN_* */
+   unsigned char property_fs_coord_pixel_center; /* = TGSI_FS_COORD_PIXEL_CENTER_* */
 
    unsigned nr_addrs;
    unsigned nr_preds;
@@ -265,6 +267,20 @@ ureg_property_gs_max_vertices(struct ureg_program *ureg,
    ureg->property_gs_max_vertices = max_vertices;
 }
 
+void
+ureg_property_fs_coord_origin(struct ureg_program *ureg,
+                            unsigned fs_coord_origin)
+{
+   ureg->property_fs_coord_origin = fs_coord_origin;
+}
+
+void
+ureg_property_fs_coord_pixel_center(struct ureg_program *ureg,
+                            unsigned fs_coord_pixel_center)
+{
+   ureg->property_fs_coord_pixel_center = fs_coord_pixel_center;
+}
+
 
 
 struct ureg_src 
@@ -1202,6 +1218,22 @@ static void emit_decls( struct ureg_program *ureg )
                     ureg->property_gs_max_vertices);
    }
 
+   if (ureg->property_fs_coord_origin) {
+      assert(ureg->processor == TGSI_PROCESSOR_FRAGMENT);
+
+      emit_property(ureg,
+                    TGSI_PROPERTY_FS_COORD_ORIGIN,
+                    ureg->property_fs_coord_origin);
+   }
+
+   if (ureg->property_fs_coord_pixel_center) {
+      assert(ureg->processor == TGSI_PROCESSOR_FRAGMENT);
+
+      emit_property(ureg,
+                    TGSI_PROPERTY_FS_COORD_PIXEL_CENTER,
+                    ureg->property_fs_coord_pixel_center);
+   }
+
    if (ureg->processor == TGSI_PROCESSOR_VERTEX) {
       for (i = 0; i < UREG_MAX_INPUT; i++) {
          if (ureg->vs_inputs[i/32] & (1 << (i%32))) {