[Mesa-dev] [PATCH 10/10] i965: Support 32 texture image units on Haswell+.

[Kenneth Graunke]

The Intel closed source OpenGL driver recently began supporting 32
texture image units on Haswell.  This makes the open source driver
support 32 as well.

Earlier generations don't have the message header field required to
support more than 16 sampler states, so we continue to advertise 16
there.

On Haswell, this causes us to advertise:
- GL_MAX_TEXTURE_IMAGE_UNITS = 32
- GL_MAX_VERTEX_TEXTURE_IMAGE_UNITS = 32
- GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS = 96
instead of the old values of 16, 16, and 48.

Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
---
 src/mesa/drivers/dri/i965/brw_context.c | 9 ++++++---
 src/mesa/drivers/dri/i965/brw_context.h | 2 +-
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_context.c b/src/mesa/drivers/dri/i965/brw_context.c
index 1b42751..806f3db 100644
--- a/src/mesa/drivers/dri/i965/brw_context.c
+++ b/src/mesa/drivers/dri/i965/brw_context.c
@@ -282,20 +282,23 @@ brw_initialize_context_constants(struct brw_context *brw)
 {
    struct gl_context *ctx = &brw->ctx;
 
+   unsigned max_samplers =
+      brw->gen >= 8 || brw->is_haswell ? BRW_MAX_TEX_UNIT : 16;
+
    ctx->Const.QueryCounterBits.Timestamp = 36;
 
    ctx->Const.StripTextureBorder = true;
 
    ctx->Const.MaxDualSourceDrawBuffers = 1;
    ctx->Const.MaxDrawBuffers = BRW_MAX_DRAW_BUFFERS;
-   ctx->Const.Program[MESA_SHADER_FRAGMENT].MaxTextureImageUnits = BRW_MAX_TEX_UNIT;
+   ctx->Const.Program[MESA_SHADER_FRAGMENT].MaxTextureImageUnits = max_samplers;
    ctx->Const.MaxTextureCoordUnits = 8; /* Mesa limit */
    ctx->Const.MaxTextureUnits =
       MIN2(ctx->Const.MaxTextureCoordUnits,
            ctx->Const.Program[MESA_SHADER_FRAGMENT].MaxTextureImageUnits);
-   ctx->Const.Program[MESA_SHADER_VERTEX].MaxTextureImageUnits = BRW_MAX_TEX_UNIT;
+   ctx->Const.Program[MESA_SHADER_VERTEX].MaxTextureImageUnits = max_samplers;
    if (brw->gen >= 7)
-      ctx->Const.Program[MESA_SHADER_GEOMETRY].MaxTextureImageUnits = BRW_MAX_TEX_UNIT;
+      ctx->Const.Program[MESA_SHADER_GEOMETRY].MaxTextureImageUnits = max_samplers;
    else
       ctx->Const.Program[MESA_SHADER_GEOMETRY].MaxTextureImageUnits = 0;
    ctx->Const.MaxCombinedTextureImageUnits =
diff --git a/src/mesa/drivers/dri/i965/brw_context.h b/src/mesa/drivers/dri/i965/brw_context.h
index 63dd4a0..5908659 100644
--- a/src/mesa/drivers/dri/i965/brw_context.h
+++ b/src/mesa/drivers/dri/i965/brw_context.h
@@ -650,7 +650,7 @@ struct brw_gs_prog_data
 };
 
 /** Number of texture sampler units */
-#define BRW_MAX_TEX_UNIT 16
+#define BRW_MAX_TEX_UNIT 32
 
 /** Max number of render targets in a shader */
 #define BRW_MAX_DRAW_BUFFERS 8
-- 
1.8.5.2