gallium: Add a cap for offset_units_unscaled

D3D9 has a different behaviour for depth bias.

For OGL/D3D1X, the depth bias unit is the
minimal resolvable value for the depth buffer,
which depends on the format (and has different
behaviour for float depth buffers).

For D3D9, the depth bias unit is 1.0f.

Signed-off-by: Axel Davy <[email protected]>
Reviewed-by: Marek Olšák <[email protected]>

19 files changed, 31 insertions, 0 deletions

diff --git a/src/gallium/docs/source/cso/rasterizer.rst b/src/gallium/docs/source/cso/rasterizer.rst
index 8d473b8446e..616e4511a2d 100644
--- a/src/gallium/docs/source/cso/rasterizer.rst
+++ b/src/gallium/docs/source/cso/rasterizer.rst
@@ -127,6 +127,12 @@ offset_tri
 
 offset_units
     Specifies the polygon offset bias
+offset_units_unscaled
+    Specifies the unit of the polygon offset bias. If false, use the
+    GL/D3D1X behaviour. If true, offset_units is a floating point offset
+    which isn't scaled (D3D9). Note that GL/D3D1X behaviour has different
+    formula whether the depth buffer is unorm or float, which is not
+    the case for D3D9.
 offset_scale
     Specifies the polygon offset scale
 offset_clamp
diff --git a/src/gallium/docs/source/screen.rst b/src/gallium/docs/source/screen.rst
index a20b372b1a9..141b45aa805 100644
--- a/src/gallium/docs/source/screen.rst
+++ b/src/gallium/docs/source/screen.rst
@@ -343,6 +343,8 @@ The integer capabilities:
 * ``PIPE_CAP_TGSI_VOTE``: Whether the ``VOTE_*`` ops can be used in shaders.
 * ``PIPE_CAP_MAX_WINDOW_RECTANGLES``: The maxium number of window rectangles
   supported in ``set_window_rectangles``.
+* ``PIPE_CAP_POLYGON_OFFSET_UNITS_UNSCALED``: If true, the driver implements support
+  for ``pipe_rasterizer_state::offset_units_unscaled``.
 
 
 .. _pipe_capf:
diff --git a/src/gallium/drivers/freedreno/freedreno_screen.c b/src/gallium/drivers/freedreno/freedreno_screen.c
index 91380241f3c..93b70e0884e 100644
--- a/src/gallium/drivers/freedreno/freedreno_screen.c
+++ b/src/gallium/drivers/freedreno/freedreno_screen.c
@@ -264,6 +264,7 @@ fd_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
 	case PIPE_CAP_PRIMITIVE_RESTART_FOR_PATCHES:
 	case PIPE_CAP_TGSI_VOTE:
 	case PIPE_CAP_MAX_WINDOW_RECTANGLES:
+	case PIPE_CAP_POLYGON_OFFSET_UNITS_UNSCALED:
 		return 0;
 
 	case PIPE_CAP_MAX_VIEWPORTS:
diff --git a/src/gallium/drivers/i915/i915_screen.c b/src/gallium/drivers/i915/i915_screen.c
index e898f7ee20a..3f0ab98a3c5 100644
--- a/src/gallium/drivers/i915/i915_screen.c
+++ b/src/gallium/drivers/i915/i915_screen.c
@@ -275,6 +275,7 @@ i915_get_param(struct pipe_screen *screen, enum pipe_cap cap)
    case PIPE_CAP_PRIMITIVE_RESTART_FOR_PATCHES:
    case PIPE_CAP_TGSI_VOTE:
    case PIPE_CAP_MAX_WINDOW_RECTANGLES:
+   case PIPE_CAP_POLYGON_OFFSET_UNITS_UNSCALED:
       return 0;
 
    case PIPE_CAP_MAX_DUAL_SOURCE_RENDER_TARGETS:
diff --git a/src/gallium/drivers/ilo/ilo_screen.c b/src/gallium/drivers/ilo/ilo_screen.c
index a775aa60dc2..2024688ecdb 100644
--- a/src/gallium/drivers/ilo/ilo_screen.c
+++ b/src/gallium/drivers/ilo/ilo_screen.c
@@ -504,6 +504,7 @@ ilo_get_param(struct pipe_screen *screen, enum pipe_cap param)
    case PIPE_CAP_PRIMITIVE_RESTART_FOR_PATCHES:
    case PIPE_CAP_TGSI_VOTE:
    case PIPE_CAP_MAX_WINDOW_RECTANGLES:
+   case PIPE_CAP_POLYGON_OFFSET_UNITS_UNSCALED:
       return 0;
 
    case PIPE_CAP_VENDOR_ID:
diff --git a/src/gallium/drivers/llvmpipe/lp_screen.c b/src/gallium/drivers/llvmpipe/lp_screen.c
index 7d01e6458f7..684c7a539ef 100644
--- a/src/gallium/drivers/llvmpipe/lp_screen.c
+++ b/src/gallium/drivers/llvmpipe/lp_screen.c
@@ -327,6 +327,7 @@ llvmpipe_get_param(struct pipe_screen *screen, enum pipe_cap param)
    case PIPE_CAP_PRIMITIVE_RESTART_FOR_PATCHES:
    case PIPE_CAP_TGSI_VOTE:
    case PIPE_CAP_MAX_WINDOW_RECTANGLES:
+   case PIPE_CAP_POLYGON_OFFSET_UNITS_UNSCALED:
       return 0;
    }
    /* should only get here on unhandled cases */
diff --git a/src/gallium/drivers/nouveau/nv30/nv30_screen.c b/src/gallium/drivers/nouveau/nv30/nv30_screen.c
index 0a3d8b2faba..68d8317bd60 100644
--- a/src/gallium/drivers/nouveau/nv30/nv30_screen.c
+++ b/src/gallium/drivers/nouveau/nv30/nv30_screen.c
@@ -198,6 +198,7 @@ nv30_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
    case PIPE_CAP_PRIMITIVE_RESTART_FOR_PATCHES:
    case PIPE_CAP_TGSI_VOTE:
    case PIPE_CAP_MAX_WINDOW_RECTANGLES:
+   case PIPE_CAP_POLYGON_OFFSET_UNITS_UNSCALED:
       return 0;
 
    case PIPE_CAP_VENDOR_ID:
diff --git a/src/gallium/drivers/nouveau/nv50/nv50_screen.c b/src/gallium/drivers/nouveau/nv50/nv50_screen.c
index 042148e7455..303ecf121ae 100644
--- a/src/gallium/drivers/nouveau/nv50/nv50_screen.c
+++ b/src/gallium/drivers/nouveau/nv50/nv50_screen.c
@@ -252,6 +252,7 @@ nv50_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
    case PIPE_CAP_ROBUST_BUFFER_ACCESS_BEHAVIOR:
    case PIPE_CAP_PRIMITIVE_RESTART_FOR_PATCHES:
    case PIPE_CAP_TGSI_VOTE:
+   case PIPE_CAP_POLYGON_OFFSET_UNITS_UNSCALED:
       return 0;
 
    case PIPE_CAP_VENDOR_ID:
diff --git a/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c b/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c
index 08ec4136880..a5c37c5b713 100644
--- a/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c
+++ b/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c
@@ -263,6 +263,7 @@ nvc0_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
    case PIPE_CAP_PCI_BUS:
    case PIPE_CAP_PCI_DEVICE:
    case PIPE_CAP_PCI_FUNCTION:
+   case PIPE_CAP_POLYGON_OFFSET_UNITS_UNSCALED:
       return 0;
 
    case PIPE_CAP_VENDOR_ID:
diff --git a/src/gallium/drivers/r300/r300_screen.c b/src/gallium/drivers/r300/r300_screen.c
index 8822b4d11bd..d47b70d65b3 100644
--- a/src/gallium/drivers/r300/r300_screen.c
+++ b/src/gallium/drivers/r300/r300_screen.c
@@ -220,6 +220,7 @@ static int r300_get_param(struct pipe_screen* pscreen, enum pipe_cap param)
         case PIPE_CAP_PRIMITIVE_RESTART_FOR_PATCHES:
         case PIPE_CAP_TGSI_VOTE:
         case PIPE_CAP_MAX_WINDOW_RECTANGLES:
+        case PIPE_CAP_POLYGON_OFFSET_UNITS_UNSCALED:
             return 0;
 
         /* SWTCL-only features. */
diff --git a/src/gallium/drivers/r600/r600_pipe.c b/src/gallium/drivers/r600/r600_pipe.c
index f4811c4feaa..fe1af7c64bb 100644
--- a/src/gallium/drivers/r600/r600_pipe.c
+++ b/src/gallium/drivers/r600/r600_pipe.c
@@ -370,6 +370,7 @@ static int r600_get_param(struct pipe_screen* pscreen, enum pipe_cap param)
 	case PIPE_CAP_PRIMITIVE_RESTART_FOR_PATCHES:
 	case PIPE_CAP_TGSI_VOTE:
 	case PIPE_CAP_MAX_WINDOW_RECTANGLES:
+	case PIPE_CAP_POLYGON_OFFSET_UNITS_UNSCALED:
 		return 0;
 
 	case PIPE_CAP_MAX_SHADER_PATCH_VARYINGS:
diff --git a/src/gallium/drivers/radeonsi/si_pipe.c b/src/gallium/drivers/radeonsi/si_pipe.c
index 3259d5f42b2..37406aa27d6 100644
--- a/src/gallium/drivers/radeonsi/si_pipe.c
+++ b/src/gallium/drivers/radeonsi/si_pipe.c
@@ -415,6 +415,7 @@ static int si_get_param(struct pipe_screen* pscreen, enum pipe_cap param)
 	case PIPE_CAP_PRIMITIVE_RESTART_FOR_PATCHES:
 	case PIPE_CAP_TGSI_VOTE:
 	case PIPE_CAP_MAX_WINDOW_RECTANGLES:
+	case PIPE_CAP_POLYGON_OFFSET_UNITS_UNSCALED:
 		return 0;
 
 	case PIPE_CAP_MAX_SHADER_PATCH_VARYINGS:
diff --git a/src/gallium/drivers/softpipe/sp_screen.c b/src/gallium/drivers/softpipe/sp_screen.c
index a4b2299c26f..93022db8055 100644
--- a/src/gallium/drivers/softpipe/sp_screen.c
+++ b/src/gallium/drivers/softpipe/sp_screen.c
@@ -277,6 +277,7 @@ softpipe_get_param(struct pipe_screen *screen, enum pipe_cap param)
    case PIPE_CAP_PRIMITIVE_RESTART_FOR_PATCHES:
    case PIPE_CAP_TGSI_VOTE:
    case PIPE_CAP_MAX_WINDOW_RECTANGLES:
+   case PIPE_CAP_POLYGON_OFFSET_UNITS_UNSCALED:
       return 0;
    case PIPE_CAP_SHADER_BUFFER_OFFSET_ALIGNMENT:
       return 4;
diff --git a/src/gallium/drivers/svga/svga_screen.c b/src/gallium/drivers/svga/svga_screen.c
index f6f53afe7ea..4c2774d3f17 100644
--- a/src/gallium/drivers/svga/svga_screen.c
+++ b/src/gallium/drivers/svga/svga_screen.c
@@ -410,6 +410,7 @@ svga_get_param(struct pipe_screen *screen, enum pipe_cap param)
    case PIPE_CAP_PRIMITIVE_RESTART_FOR_PATCHES:
    case PIPE_CAP_TGSI_VOTE:
    case PIPE_CAP_MAX_WINDOW_RECTANGLES:
+   case PIPE_CAP_POLYGON_OFFSET_UNITS_UNSCALED:
       return 0;
    }
 
diff --git a/src/gallium/drivers/swr/swr_screen.cpp b/src/gallium/drivers/swr/swr_screen.cpp
index 792b09cd438..d4784057512 100644
--- a/src/gallium/drivers/swr/swr_screen.cpp
+++ b/src/gallium/drivers/swr/swr_screen.cpp
@@ -363,6 +363,7 @@ swr_get_param(struct pipe_screen *screen, enum pipe_cap param)
    case PIPE_CAP_PRIMITIVE_RESTART_FOR_PATCHES:
    case PIPE_CAP_TGSI_VOTE:
    case PIPE_CAP_MAX_WINDOW_RECTANGLES:
+   case PIPE_CAP_POLYGON_OFFSET_UNITS_UNSCALED:
       return 0;
    }
 
diff --git a/src/gallium/drivers/vc4/vc4_screen.c b/src/gallium/drivers/vc4/vc4_screen.c
index c38e4f4381f..0f0d119b1df 100644
--- a/src/gallium/drivers/vc4/vc4_screen.c
+++ b/src/gallium/drivers/vc4/vc4_screen.c
@@ -213,6 +213,7 @@ vc4_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
         case PIPE_CAP_PRIMITIVE_RESTART_FOR_PATCHES:
         case PIPE_CAP_TGSI_VOTE:
         case PIPE_CAP_MAX_WINDOW_RECTANGLES:
+        case PIPE_CAP_POLYGON_OFFSET_UNITS_UNSCALED:
                 return 0;
 
                 /* Stream output. */
diff --git a/src/gallium/drivers/virgl/virgl_screen.c b/src/gallium/drivers/virgl/virgl_screen.c
index 65574fae788..b94b0171674 100644
--- a/src/gallium/drivers/virgl/virgl_screen.c
+++ b/src/gallium/drivers/virgl/virgl_screen.c
@@ -245,6 +245,7 @@ virgl_get_param(struct pipe_screen *screen, enum pipe_cap param)
    case PIPE_CAP_PRIMITIVE_RESTART_FOR_PATCHES:
    case PIPE_CAP_TGSI_VOTE:
    case PIPE_CAP_MAX_WINDOW_RECTANGLES:
+   case PIPE_CAP_POLYGON_OFFSET_UNITS_UNSCALED:
       return 0;
    case PIPE_CAP_VENDOR_ID:
       return 0x1af4;
diff --git a/src/gallium/include/pipe/p_defines.h b/src/gallium/include/pipe/p_defines.h
index c46ac5a6a63..62fa67374f2 100644
--- a/src/gallium/include/pipe/p_defines.h
+++ b/src/gallium/include/pipe/p_defines.h
@@ -731,6 +731,7 @@ enum pipe_cap
    PIPE_CAP_PRIMITIVE_RESTART_FOR_PATCHES,
    PIPE_CAP_TGSI_VOTE,
    PIPE_CAP_MAX_WINDOW_RECTANGLES,
+   PIPE_CAP_POLYGON_OFFSET_UNITS_UNSCALED,
 };
 
 #define PIPE_QUIRK_TEXTURE_BORDER_COLOR_SWIZZLE_NV50 (1 << 0)
diff --git a/src/gallium/include/pipe/p_state.h b/src/gallium/include/pipe/p_state.h
index 9c693555c7e..1543e90972e 100644
--- a/src/gallium/include/pipe/p_state.h
+++ b/src/gallium/include/pipe/p_state.h
@@ -140,6 +140,13 @@ struct pipe_rasterizer_state
    unsigned clip_halfz:1;
 
    /**
+    * When true do not scale offset_units and use same rules for unorm and
+    * float depth buffers (D3D9). When false use GL/D3D1X behaviour.
+    * This depends on PIPE_CAP_POLYGON_OFFSET_UNITS_UNSCALED.
+    */
+   unsigned offset_units_unscaled:1;
+
+   /**
     * Enable bits for clipping half-spaces.
     * This applies to both user clip planes and shader clip distances.
     * Note that if the bound shader exports any clip distances, these