[Mesa-dev] [PATCH 1/2] mesa: Track max enabled tex image unit

[Chris Forbes]

This gives us a better bound for some hot loops in the drivers than
MAX_COMBINED_TEXTURE_IMAGE_UNITS, which is ridiculously large on modern
hardware, and only getting worse as more shader stages are added.

Signed-off-by: Chris Forbes <chrisf at ijw.co.nz>
---
 src/mesa/main/mtypes.h   | 3 +++
 src/mesa/main/texstate.c | 2 ++
 2 files changed, 5 insertions(+)

diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index 4d014d1..6694383 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -1402,6 +1402,9 @@ struct gl_texture_attrib
 
    /** Bitwise-OR of all Texture.Unit[i]._GenFlags */
    GLbitfield _GenFlags;
+
+   /** Upper bound on _ReallyEnabled texunits. */
+   GLint _MaxEnabledTexImageUnit;
 };
 
 
diff --git a/src/mesa/main/texstate.c b/src/mesa/main/texstate.c
index fcae878..b68920c 100644
--- a/src/mesa/main/texstate.c
+++ b/src/mesa/main/texstate.c
@@ -550,6 +550,7 @@ update_texture_state( struct gl_context *ctx )
    ctx->Texture._GenFlags = 0x0;
    ctx->Texture._TexMatEnabled = 0x0;
    ctx->Texture._TexGenEnabled = 0x0;
+   ctx->Texture._MaxEnabledTexImageUnit = -1;
 
    /*
     * Update texture unit state.
@@ -636,6 +637,7 @@ update_texture_state( struct gl_context *ctx )
       /* if we get here, we know this texture unit is enabled */
 
       ctx->Texture._EnabledUnits |= (1 << unit);
+      ctx->Texture._MaxEnabledTexImageUnit = unit;
 
       if (enabledTargetsByStage[MESA_SHADER_FRAGMENT])
          enabledFragUnits |= (1 << unit);
-- 
1.9.2