i965: add software fallback for conformant 3D textures and GL_CLAMP

The i965 hardware cannot do GL_CLAMP behavior on textures; an earlier
commit forced a software fallback if strict conformance was required
(i.e. the INTEL_STRICT_CONFORMANCE environment variable was set) and
2D textures were used, but it was somewhat flawed - it could trigger
the software fallback even if 2D textures weren't enabled, as long
as one texture unit was enabled.

This fixes that, and adds software fallback for GL_CLAMP behavior with
1D and 3D textures.

It also adds support for a particular setting of the INTEL_STRICT_CONFORMANCE
environment variable, which forces software fallbacks to be taken *all*
the time.  This is helpful with debugging.  The value is:
   export INTEL_STRICT_CONFORMANCE=2

1 files changed, 8 insertions, 2 deletions

diff --git a/src/mesa/drivers/dri/intel/intel_context.c b/src/mesa/drivers/dri/intel/intel_context.c
index b3f6fc02df..65853234f1 100644
--- a/src/mesa/drivers/dri/intel/intel_context.c
+++ b/src/mesa/drivers/dri/intel/intel_context.c
@@ -506,10 +506,16 @@ intelInitContext(struct intel_context *intel,
     * start.
     */
    if (getenv("INTEL_STRICT_CONFORMANCE")) {
-      intel->strict_conformance = 1;
+      unsigned int value = atoi(getenv("INTEL_STRICT_CONFORMANCE"));
+      if (value > 0) {
+         intel->conformance_mode = value;
+      }
+      else {
+         intel->conformance_mode = 1;
+      }
    }
 
-   if (intel->strict_conformance) {
+   if (intel->conformance_mode > 0) {
       ctx->Const.MinLineWidth = 1.0;
       ctx->Const.MinLineWidthAA = 1.0;
       ctx->Const.MaxLineWidth = 1.0;