[Mesa-dev] [PATCH 7/8] gallium: create TGSI_PROPERTY to disable viewport and clipping

[Automated rebase]

From: Christoph Bumiller <e0425955 at student.tuwien.ac.at>

---
 src/gallium/auxiliary/tgsi/tgsi_strings.c  |  3 ++-
 src/gallium/auxiliary/tgsi/tgsi_ureg.c     | 16 ++++++++++++++++
 src/gallium/auxiliary/tgsi/tgsi_ureg.h     |  4 ++++
 src/gallium/docs/source/tgsi.rst           |  9 +++++++++
 src/gallium/include/pipe/p_shader_tokens.h |  3 ++-
 5 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/src/gallium/auxiliary/tgsi/tgsi_strings.c b/src/gallium/auxiliary/tgsi/tgsi_strings.c
index 5b6e47f..c3e7118 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_strings.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_strings.c
@@ -120,7 +120,8 @@ const char *tgsi_property_names[TGSI_PROPERTY_COUNT] =
    "FS_COORD_PIXEL_CENTER",
    "FS_COLOR0_WRITES_ALL_CBUFS",
    "FS_DEPTH_LAYOUT",
-   "VS_PROHIBIT_UCPS"
+   "VS_PROHIBIT_UCPS",
+   "VS_POSITION_WINDOW_SPACE"
 };
 
 const char *tgsi_type_names[5] =
diff --git a/src/gallium/auxiliary/tgsi/tgsi_ureg.c b/src/gallium/auxiliary/tgsi/tgsi_ureg.c
index 2bf93ee..bd0a3f7 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_ureg.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_ureg.c
@@ -173,6 +173,7 @@ struct ureg_program
    unsigned char property_fs_coord_pixel_center; /* = TGSI_FS_COORD_PIXEL_CENTER_* */
    unsigned char property_fs_color0_writes_all_cbufs; /* = TGSI_FS_COLOR0_WRITES_ALL_CBUFS * */
    unsigned char property_fs_depth_layout; /* TGSI_FS_DEPTH_LAYOUT */
+   boolean property_vs_window_space_position; /* TGSI_VS_WINDOW_SPACE_POSITION */
 
    unsigned nr_addrs;
    unsigned nr_preds;
@@ -331,6 +332,13 @@ ureg_property_fs_depth_layout(struct ureg_program *ureg,
    ureg->property_fs_depth_layout = fs_depth_layout;
 }
 
+void
+ureg_property_vs_window_space_position(struct ureg_program *ureg,
+                                       boolean vs_window_space_position)
+{
+   ureg->property_vs_window_space_position = vs_window_space_position;
+}
+
 struct ureg_src
 ureg_DECL_fs_input_cyl_centroid(struct ureg_program *ureg,
                        unsigned semantic_name,
@@ -1508,6 +1516,14 @@ static void emit_decls( struct ureg_program *ureg )
                     ureg->property_fs_depth_layout);
    }
 
+   if (ureg->property_vs_window_space_position) {
+      assert(ureg->processor == TGSI_PROCESSOR_VERTEX);
+
+      emit_property(ureg,
+                    TGSI_PROPERTY_VS_WINDOW_SPACE_POSITION,
+                    ureg->property_vs_window_space_position);
+   }
+
    if (ureg->processor == TGSI_PROCESSOR_VERTEX) {
       for (i = 0; i < UREG_MAX_INPUT; i++) {
          if (ureg->vs_inputs[i/32] & (1 << (i%32))) {
diff --git a/src/gallium/auxiliary/tgsi/tgsi_ureg.h b/src/gallium/auxiliary/tgsi/tgsi_ureg.h
index a0a50b7..28edea6 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_ureg.h
+++ b/src/gallium/auxiliary/tgsi/tgsi_ureg.h
@@ -184,6 +184,10 @@ void
 ureg_property_fs_depth_layout(struct ureg_program *ureg,
                               unsigned fs_depth_layout);
 
+void
+ureg_property_vs_window_space_position(struct ureg_program *ureg,
+                                       boolean vs_window_space_position);
+
 
 /***********************************************************************
  * Build shader declarations:
diff --git a/src/gallium/docs/source/tgsi.rst b/src/gallium/docs/source/tgsi.rst
index 9500b9d..2ca3c3b 100644
--- a/src/gallium/docs/source/tgsi.rst
+++ b/src/gallium/docs/source/tgsi.rst
@@ -2848,6 +2848,15 @@ input primitive. Each invocation will have a different
 TGSI_SEMANTIC_INVOCATIONID system value set. If not specified, assumed to
 be 1.
 
+VS_WINDOW_SPACE_POSITION
+""""""""""""""""""""""""""
+If this property is set on the vertex shader, the TGSI_SEMANTIC_POSITION output
+is assumed to contain window space coordinates.
+Division of X,Y,Z by W and the viewport transformation are disabled, and 1/W is
+directly taken from the 4-th component of the shader output.
+Naturally, clipping is not performed on window coordinates either.
+The effect of this property is undefined if a geometry or tessellation shader
+are in use.
 
 Texture Sampling and Texture Formats
 ------------------------------------
diff --git a/src/gallium/include/pipe/p_shader_tokens.h b/src/gallium/include/pipe/p_shader_tokens.h
index d095bd3..9261b79 100644
--- a/src/gallium/include/pipe/p_shader_tokens.h
+++ b/src/gallium/include/pipe/p_shader_tokens.h
@@ -237,7 +237,8 @@ union tgsi_immediate_data
 #define TGSI_PROPERTY_FS_DEPTH_LAYOUT        6
 #define TGSI_PROPERTY_VS_PROHIBIT_UCPS       7
 #define TGSI_PROPERTY_GS_INVOCATIONS         8
-#define TGSI_PROPERTY_COUNT                  9
+#define TGSI_PROPERTY_VS_WINDOW_SPACE_POSITION 9
+#define TGSI_PROPERTY_COUNT                  10
 
 struct tgsi_property {
    unsigned Type         : 4;  /**< TGSI_TOKEN_TYPE_PROPERTY */
-- 
1.9.2