mesa: add new signed rgba texture format

This is a (partial) backport of the signed texture format support in OGL 3.1.
Since it wasn't promoted from an existing extension roll our own.

1 files changed, 41 insertions, 3 deletions

diff --git a/src/mesa/main/texformat.c b/src/mesa/main/texformat.c
index c372b49398..0ceaaf3ece 100644
--- a/src/mesa/main/texformat.c
+++ b/src/mesa/main/texformat.c
@@ -699,9 +699,7 @@ const struct gl_texture_format _mesa_texformat_intensity_float16 = {
 const struct gl_texture_format _mesa_texformat_dudv8 = {
    MESA_FORMAT_DUDV8,			/* MesaFormat */
    GL_DUDV_ATI,				/* BaseFormat */
-   /* FIXME: spec doesn't say since that parameter didn't exist then,
-      but this should be something like SIGNED_NORMALIZED */
-   GL_UNSIGNED_NORMALIZED_ARB,		/* DataType */
+   GL_SIGNED_NORMALIZED,		/* DataType */
    /* maybe should add dudvBits field, but spec seems to be
       lacking the ability to query with GetTexLevelParameter anyway */
    0,					/* RedBits */
@@ -724,6 +722,30 @@ const struct gl_texture_format _mesa_texformat_dudv8 = {
    NULL					/* StoreTexel */
 };
 
+const struct gl_texture_format _mesa_texformat_signed_rgba8888 = {
+   MESA_FORMAT_SIGNED_RGBA8888,		/* MesaFormat */
+   GL_RGBA,				/* BaseFormat */
+   GL_SIGNED_NORMALIZED,		/* DataType */
+   8,					/* RedBits */
+   8,					/* GreenBits */
+   8,					/* BlueBits */
+   8,					/* AlphaBits */
+   0,					/* LuminanceBits */
+   0,					/* IntensityBits */
+   0,					/* IndexBits */
+   0,					/* DepthBits */
+   0,					/* StencilBits */
+   4,					/* TexelBytes */
+   _mesa_texstore_signed_rgba8888,	/* StoreTexImageFunc */
+   NULL,				/* FetchTexel1D */
+   NULL,				/* FetchTexel2D */
+   NULL,				/* FetchTexel3D */
+   fetch_texel_1d_signed_rgba8888,	/* FetchTexel1Df */
+   fetch_texel_2d_signed_rgba8888,	/* FetchTexel2Df */
+   fetch_texel_3d_signed_rgba8888,	/* FetchTexel3Df */
+   store_texel_signed_rgba8888		/* StoreTexel */
+};
+
 /*@}*/
 
 
@@ -1671,6 +1693,17 @@ _mesa_choose_tex_format( GLcontext *ctx, GLint internalFormat,
       }
    }
 
+   if (ctx->Extensions.MESA_texture_signed_rgba) {
+      switch (internalFormat) {
+         case GL_RGBA_SNORM:
+         case GL_RGBA8_SNORM:
+            return &_mesa_texformat_signed_rgba8888;
+         default:
+            ; /* fallthrough */
+      }
+   }
+
+
 #if FEATURE_EXT_texture_sRGB
    if (ctx->Extensions.EXT_texture_sRGB) {
       switch (internalFormat) {
@@ -1820,6 +1853,11 @@ _mesa_format_to_type_and_comps(const struct gl_texture_format *format,
       *comps = 2;
       return;
 
+   case MESA_FORMAT_SIGNED_RGBA8888:
+      *datatype = GL_BYTE;
+      *comps = 4;
+      return;
+
 #if FEATURE_EXT_texture_sRGB
    case MESA_FORMAT_SRGB8:
       *datatype = GL_UNSIGNED_BYTE;