gallium: add red-alpha texture formats and a couple of util functions

This is for glGetTexImage and it will be used for samplers only (which some
drivers already implement by reading util_format_description).

v2: incorporate Brian's suggestion

Reviewed-by: Brian Paul <brianp@vmware.com>

3 files changed, 141 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/util/u_format.csv b/src/gallium/auxiliary/util/u_format.csv
index 1d274076b0f..f3925bb3ca2 100644
--- a/src/gallium/auxiliary/util/u_format.csv
+++ b/src/gallium/auxiliary/util/u_format.csv
@@ -360,3 +360,15 @@ PIPE_FORMAT_R16G16B16X16_SINT       , plain, 1, 1, sp16, sp16, sp16, x16, xyz1,
 PIPE_FORMAT_R32G32B32X32_FLOAT      , plain, 1, 1, f32,  f32,  f32,  x32, xyz1, rgb
 PIPE_FORMAT_R32G32B32X32_UINT       , plain, 1, 1, up32, up32, up32, x32, xyz1, rgb
 PIPE_FORMAT_R32G32B32X32_SINT       , plain, 1, 1, sp32, sp32, sp32, x32, xyz1, rgb
+
+PIPE_FORMAT_R8A8_SNORM              , plain, 1, 1, sn8  ,  sn8 ,     ,     , x00y, rgb
+PIPE_FORMAT_R16A16_UNORM            , plain, 1, 1, un16 , un16 ,     ,     , x00y, rgb
+PIPE_FORMAT_R16A16_SNORM            , plain, 1, 1, sn16 , sn16 ,     ,     , x00y, rgb
+PIPE_FORMAT_R16A16_FLOAT            , plain, 1, 1, f16  , f16  ,     ,     , x00y, rgb
+PIPE_FORMAT_R32A32_FLOAT            , plain, 1, 1, f32  , f32  ,     ,     , x00y, rgb
+PIPE_FORMAT_R8A8_UINT               , plain, 1, 1, up8  , up8  ,     ,     , x00y, rgb
+PIPE_FORMAT_R8A8_SINT               , plain, 1, 1, sp8  , sp8  ,     ,     , x00y, rgb
+PIPE_FORMAT_R16A16_UINT             , plain, 1, 1, up16 , up16 ,     ,     , x00y, rgb
+PIPE_FORMAT_R16A16_SINT             , plain, 1, 1, sp16 , sp16 ,     ,     , x00y, rgb
+PIPE_FORMAT_R32A32_UINT             , plain, 1, 1, up32 , up32 ,     ,     , x00y, rgb
+PIPE_FORMAT_R32A32_SINT             , plain, 1, 1, sp32 , sp32 ,     ,     , x00y, rgb
diff --git a/src/gallium/auxiliary/util/u_format.h b/src/gallium/auxiliary/util/u_format.h
index 63015dd50c1..00301265db8 100644
--- a/src/gallium/auxiliary/util/u_format.h
+++ b/src/gallium/auxiliary/util/u_format.h
@@ -888,6 +888,123 @@ util_format_stencil_only(enum pipe_format format)
 }
 
 /**
+ * Converts PIPE_FORMAT_*I* to PIPE_FORMAT_*R*.
+ * This is identity for non-intensity formats.
+ */
+static INLINE enum pipe_format
+util_format_intensity_to_red(enum pipe_format format)
+{
+   switch (format) {
+   case PIPE_FORMAT_I8_UNORM:
+      return PIPE_FORMAT_R8_UNORM;
+   case PIPE_FORMAT_I8_SNORM:
+      return PIPE_FORMAT_R8_SNORM;
+   case PIPE_FORMAT_I16_UNORM:
+      return PIPE_FORMAT_R16_UNORM;
+   case PIPE_FORMAT_I16_SNORM:
+      return PIPE_FORMAT_R16_SNORM;
+   case PIPE_FORMAT_I16_FLOAT:
+      return PIPE_FORMAT_R16_FLOAT;
+   case PIPE_FORMAT_I32_FLOAT:
+      return PIPE_FORMAT_R32_FLOAT;
+   case PIPE_FORMAT_I8_UINT:
+      return PIPE_FORMAT_R8_UINT;
+   case PIPE_FORMAT_I8_SINT:
+      return PIPE_FORMAT_R8_SINT;
+   case PIPE_FORMAT_I16_UINT:
+      return PIPE_FORMAT_R16_UINT;
+   case PIPE_FORMAT_I16_SINT:
+      return PIPE_FORMAT_R16_SINT;
+   case PIPE_FORMAT_I32_UINT:
+      return PIPE_FORMAT_R32_UINT;
+   case PIPE_FORMAT_I32_SINT:
+      return PIPE_FORMAT_R32_SINT;
+   default:
+      assert(!util_format_is_intensity(format));
+      return format;
+   }
+}
+
+/**
+ * Converts PIPE_FORMAT_*L* to PIPE_FORMAT_*R*.
+ * This is identity for non-luminance formats.
+ */
+static INLINE enum pipe_format
+util_format_luminance_to_red(enum pipe_format format)
+{
+   switch (format) {
+   case PIPE_FORMAT_L8_UNORM:
+      return PIPE_FORMAT_R8_UNORM;
+   case PIPE_FORMAT_L8_SNORM:
+      return PIPE_FORMAT_R8_SNORM;
+   case PIPE_FORMAT_L16_UNORM:
+      return PIPE_FORMAT_R16_UNORM;
+   case PIPE_FORMAT_L16_SNORM:
+      return PIPE_FORMAT_R16_SNORM;
+   case PIPE_FORMAT_L16_FLOAT:
+      return PIPE_FORMAT_R16_FLOAT;
+   case PIPE_FORMAT_L32_FLOAT:
+      return PIPE_FORMAT_R32_FLOAT;
+   case PIPE_FORMAT_L8_UINT:
+      return PIPE_FORMAT_R8_UINT;
+   case PIPE_FORMAT_L8_SINT:
+      return PIPE_FORMAT_R8_SINT;
+   case PIPE_FORMAT_L16_UINT:
+      return PIPE_FORMAT_R16_UINT;
+   case PIPE_FORMAT_L16_SINT:
+      return PIPE_FORMAT_R16_SINT;
+   case PIPE_FORMAT_L32_UINT:
+      return PIPE_FORMAT_R32_UINT;
+   case PIPE_FORMAT_L32_SINT:
+      return PIPE_FORMAT_R32_SINT;
+
+   case PIPE_FORMAT_LATC1_UNORM:
+      return PIPE_FORMAT_RGTC1_UNORM;
+   case PIPE_FORMAT_LATC1_SNORM:
+      return PIPE_FORMAT_RGTC1_SNORM;
+
+   case PIPE_FORMAT_L4A4_UNORM:
+      /* XXX A4R4 is defined as x00y in u_format.csv */
+      return PIPE_FORMAT_A4R4_UNORM;
+
+   case PIPE_FORMAT_L8A8_UNORM:
+      return PIPE_FORMAT_R8A8_UNORM;
+   case PIPE_FORMAT_L8A8_SNORM:
+      return PIPE_FORMAT_R8A8_SNORM;
+   case PIPE_FORMAT_L16A16_UNORM:
+      return PIPE_FORMAT_R16A16_UNORM;
+   case PIPE_FORMAT_L16A16_SNORM:
+      return PIPE_FORMAT_R16A16_SNORM;
+   case PIPE_FORMAT_L16A16_FLOAT:
+      return PIPE_FORMAT_R16A16_FLOAT;
+   case PIPE_FORMAT_L32A32_FLOAT:
+      return PIPE_FORMAT_R32A32_FLOAT;
+   case PIPE_FORMAT_L8A8_UINT:
+      return PIPE_FORMAT_R8A8_UINT;
+   case PIPE_FORMAT_L8A8_SINT:
+      return PIPE_FORMAT_R8A8_SINT;
+   case PIPE_FORMAT_L16A16_UINT:
+      return PIPE_FORMAT_R16A16_UINT;
+   case PIPE_FORMAT_L16A16_SINT:
+      return PIPE_FORMAT_R16A16_SINT;
+   case PIPE_FORMAT_L32A32_UINT:
+      return PIPE_FORMAT_R32A32_UINT;
+   case PIPE_FORMAT_L32A32_SINT:
+      return PIPE_FORMAT_R32A32_SINT;
+
+   /* We don't have compressed red-alpha variants for these. */
+   case PIPE_FORMAT_LATC2_UNORM:
+   case PIPE_FORMAT_LATC2_SNORM:
+      return PIPE_FORMAT_NONE;
+
+   default:
+      assert(!util_format_is_luminance(format) &&
+	     !util_format_is_luminance_alpha(format));
+      return format;
+   }
+}
+
+/**
  * Return the number of components stored.
  * Formats with block size != 1x1 will always have 1 component (the block).
  */
diff --git a/src/gallium/include/pipe/p_format.h b/src/gallium/include/pipe/p_format.h
index 5a3d000bbe4..098b25b7dc3 100644
--- a/src/gallium/include/pipe/p_format.h
+++ b/src/gallium/include/pipe/p_format.h
@@ -328,6 +328,18 @@ enum pipe_format {
    PIPE_FORMAT_R32G32B32X32_UINT       = 240,
    PIPE_FORMAT_R32G32B32X32_SINT       = 241,
 
+   PIPE_FORMAT_R8A8_SNORM              = 242,
+   PIPE_FORMAT_R16A16_UNORM            = 243,
+   PIPE_FORMAT_R16A16_SNORM            = 244,
+   PIPE_FORMAT_R16A16_FLOAT            = 245,
+   PIPE_FORMAT_R32A32_FLOAT            = 246,
+   PIPE_FORMAT_R8A8_UINT               = 247,
+   PIPE_FORMAT_R8A8_SINT               = 248,
+   PIPE_FORMAT_R16A16_UINT             = 249,
+   PIPE_FORMAT_R16A16_SINT             = 250,
+   PIPE_FORMAT_R32A32_UINT             = 251,
+   PIPE_FORMAT_R32A32_SINT             = 252,
+
    PIPE_FORMAT_COUNT
 };