[Mesa-dev] [PATCH] mesa: Set minimum possible GLSL version

[Ian Romanick]

From: Ian Romanick <ian.d.romanick at intel.com>

Set the absolute minimum possible GLSL version.  API_OPENGL_CORE can
mean an OpenGL 3.0 forward-compatible context, so that implies a minimum
possible version of 1.30.  Otherwise, the minimum possible version 1.20.
Since Mesa unconditionally advertises GL_ARB_shading_language_100 and
GL_ARB_shader_objects, every driver has GLSL 1.20... even if they don't
advertise any extensions to enable any shader stages (e.g.,
GL_ARB_vertex_shader).

Converts about 2,500 piglit tests from crash to skip on NV18.
---
 src/mesa/main/context.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/mesa/main/context.c b/src/mesa/main/context.c
index e5a89d9c2fc..516660d55d2 100644
--- a/src/mesa/main/context.c
+++ b/src/mesa/main/context.c
@@ -616,6 +616,17 @@ _mesa_init_constants(struct gl_constants *consts, gl_api api)
    consts->MaxProgramMatrices = MAX_PROGRAM_MATRICES;
    consts->MaxProgramMatrixStackDepth = MAX_PROGRAM_MATRIX_STACK_DEPTH;
 
+   /* Set the absolute minimum possible GLSL version.  API_OPENGL_CORE can
+    * mean an OpenGL 3.0 forward-compatible context, so that implies a minimum
+    * possible version of 1.30.  Otherwise, the minimum possible version 1.20.
+    * Since Mesa unconditionally advertises GL_ARB_shading_language_100 and
+    * GL_ARB_shader_objects, every driver has GLSL 1.20... even if they don't
+    * advertise any extensions to enable any shader stages (e.g.,
+    * GL_ARB_vertex_shader).
+    */
+   consts->GLSLVersion = api == API_OPENGL_CORE ? 130 : 120;
+   consts->GLSLVersionCompat = consts->GLSLVersion;
+
    /* Assume that if GLSL 1.30+ (or GLSL ES 3.00+) is supported that
     * gl_VertexID is implemented using a native hardware register with OpenGL
     * semantics.
-- 
2.21.0