mesa: Remove EXT_blend_subtract extension enable flag

All drivers remaining in Mesa support this extension.  This extension
is either required or optional features in desktop OpenGL, OpenGL ES
1.x, and OpenGL ES 2.x.

This extension was previously not supported on i810, mach64, mga,
savage, sis, and tdfx (Voodoo Banshee and Voodoo3).

Signed-off-by: Ian Romanick <[email protected]>
Reviewed-by: Brian Paul <[email protected]>
Reviewed-by: Kenneth Graunke <[email protected]>

4 files changed, 4 insertions, 10 deletions

diff --git a/src/mesa/main/blend.c b/src/mesa/main/blend.c
index 98c14f56171..09acdf5c588 100644
--- a/src/mesa/main/blend.c
+++ b/src/mesa/main/blend.c
@@ -289,13 +289,12 @@ legal_blend_equation(const struct gl_context *ctx, GLenum mode)
 {
    switch (mode) {
    case GL_FUNC_ADD:
+   case GL_FUNC_SUBTRACT:
+   case GL_FUNC_REVERSE_SUBTRACT:
       return GL_TRUE;
    case GL_MIN:
    case GL_MAX:
       return ctx->Extensions.EXT_blend_minmax;
-   case GL_FUNC_SUBTRACT:
-   case GL_FUNC_REVERSE_SUBTRACT:
-      return ctx->Extensions.EXT_blend_subtract;
    default:
       return GL_FALSE;
    }
diff --git a/src/mesa/main/extensions.c b/src/mesa/main/extensions.c
index 0901b2dd63a..3df8c76380e 100644
--- a/src/mesa/main/extensions.c
+++ b/src/mesa/main/extensions.c
@@ -152,7 +152,7 @@ static const struct extension extension_table[] = {
    { "GL_EXT_blend_equation_separate",             o(EXT_blend_equation_separate),             GL,             2003 },
    { "GL_EXT_blend_func_separate",                 o(EXT_blend_func_separate),                 GL,             1999 },
    { "GL_EXT_blend_minmax",                        o(EXT_blend_minmax),                        GL | ES1 | ES2, 1995 },
-   { "GL_EXT_blend_subtract",                      o(EXT_blend_subtract),                      GL,             1995 },
+   { "GL_EXT_blend_subtract",                      o(dummy_true),                              GL,             1995 },
    { "GL_EXT_clip_volume_hint",                    o(EXT_clip_volume_hint),                    GL,             1996 },
    { "GL_EXT_compiled_vertex_array",               o(EXT_compiled_vertex_array),               GL,             1996 },
    { "GL_EXT_copy_texture",                        o(dummy_true),                              GL,             1995 },
@@ -216,7 +216,7 @@ static const struct extension extension_table[] = {
    /* OES extensions */
    { "GL_OES_blend_equation_separate",             o(EXT_blend_equation_separate),                  ES1,       2009 },
    { "GL_OES_blend_func_separate",                 o(EXT_blend_func_separate),                      ES1,       2009 },
-   { "GL_OES_blend_subtract",                      o(EXT_blend_subtract),                           ES1,       2009 },
+   { "GL_OES_blend_subtract",                      o(dummy_true),                                   ES1,       2009 },
    { "GL_OES_byte_coordinates",                    o(dummy_true),                                   ES1,       2002 },
    { "GL_OES_compressed_paletted_texture",         o(dummy_true),                                   ES1,       2003 },
    { "GL_OES_depth24",                             o(EXT_framebuffer_object),                       ES1 | ES2, 2005 },
@@ -448,7 +448,6 @@ _mesa_enable_sw_extensions(struct gl_context *ctx)
    ctx->Extensions.EXT_blend_equation_separate = GL_TRUE;
    ctx->Extensions.EXT_blend_func_separate = GL_TRUE;
    ctx->Extensions.EXT_blend_minmax = GL_TRUE;
-   ctx->Extensions.EXT_blend_subtract = GL_TRUE;
    ctx->Extensions.EXT_depth_bounds_test = GL_TRUE;
    ctx->Extensions.EXT_draw_buffers2 = GL_TRUE;
    ctx->Extensions.EXT_fog_coord = GL_TRUE;
@@ -553,7 +552,6 @@ _mesa_enable_1_4_extensions(struct gl_context *ctx)
    ctx->Extensions.EXT_blend_color = GL_TRUE;
    ctx->Extensions.EXT_blend_func_separate = GL_TRUE;
    ctx->Extensions.EXT_blend_minmax = GL_TRUE;
-   ctx->Extensions.EXT_blend_subtract = GL_TRUE;
    ctx->Extensions.EXT_fog_coord = GL_TRUE;
    ctx->Extensions.EXT_point_parameters = GL_TRUE;
    ctx->Extensions.EXT_secondary_color = GL_TRUE;
diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index 91cbaed88fc..63fd63d225b 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -2804,7 +2804,6 @@ struct gl_extensions
    GLboolean EXT_blend_equation_separate;
    GLboolean EXT_blend_func_separate;
    GLboolean EXT_blend_minmax;
-   GLboolean EXT_blend_subtract;
    GLboolean EXT_clip_volume_hint;
    GLboolean EXT_compiled_vertex_array;
    GLboolean EXT_depth_bounds_test;
diff --git a/src/mesa/main/version.c b/src/mesa/main/version.c
index 586bfd9454e..9c370251731 100644
--- a/src/mesa/main/version.c
+++ b/src/mesa/main/version.c
@@ -98,7 +98,6 @@ compute_version(struct gl_context *ctx)
                               ctx->Extensions.EXT_blend_color &&
                               ctx->Extensions.EXT_blend_func_separate &&
                               ctx->Extensions.EXT_blend_minmax &&
-                              ctx->Extensions.EXT_blend_subtract &&
                               ctx->Extensions.EXT_fog_coord &&
                               ctx->Extensions.EXT_point_parameters &&
                               ctx->Extensions.EXT_secondary_color);
@@ -276,7 +275,6 @@ compute_version_es2(struct gl_context *ctx)
                               ctx->Extensions.EXT_blend_color &&
                               ctx->Extensions.EXT_blend_func_separate &&
                               ctx->Extensions.EXT_blend_minmax &&
-                              ctx->Extensions.EXT_blend_subtract &&
                               ctx->Extensions.ARB_shader_objects &&
                               ctx->Extensions.ARB_vertex_shader &&
                               ctx->Extensions.ARB_fragment_shader &&