main: Allow for the possibility of GL 3.2 without ARB_geometry_shader4.

Previously, we assumed that the only way Mesa would expose geometry
shader support was via the ARB_geometry_shader4 extension.  But this
extension has some extra complications over GL 3.2 (interactions with
compatibility-only features, and link-time initialization of the
constant gl_VerticesIn).  So we want to allow for the possibility of
supporting GL 3.2 (with GLSL 1.50 style geometry shaders) even if
ctx->Extensions.ARB_geometry_shader4 is false.

This patch adds a new function, _mesa_has_geometry_shaders(), which
returns true if either ARB_geometry_shader4 is supported or the GL
version is at least 3.2 desktop.  Since compute_version() only enables
GL 3.2 functionality when GLSL 1.50 support is present, a sufficient
way for a back-end to advertise geometry shader support is to set
ctx->Const.GLSLVersion >= 150.

v2: Remove unnecessary ctx->Const.GeometryShaders150 constant.

Reviewed-by: Ian Romanick <[email protected]>
Reviewed-by: Kenneth Graunke <[email protected]>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/mesa/main/fbobject.c b/src/mesa/main/fbobject.c
index bf7e85c8826..c6e6dd5c553 100644
--- a/src/mesa/main/fbobject.c
+++ b/src/mesa/main/fbobject.c
@@ -2476,7 +2476,7 @@ _mesa_FramebufferTexture(GLenum target, GLenum attachment,
 {
    GET_CURRENT_CONTEXT(ctx);
 
-   if (ctx->Version >= 32 || ctx->Extensions.ARB_geometry_shader4) {
+   if (_mesa_has_geometry_shaders(ctx)) {
       framebuffer_texture(ctx, "Layer", target, attachment, 0, texture,
                           level, 0, GL_TRUE);
    } else {