[Mesa-dev] [PATCH 6/9] i965: Add support for GL_ARB_texture_buffer_range.

[Eric Anholt]

Supporting this extension turns out to simplify our code a bit over not
supporting this extension, once the glBufferSubData() synchronization code
lands.
---
 docs/GL3.txt                                      |  2 +-
 src/mesa/drivers/dri/i965/brw_context.c           |  1 +
 src/mesa/drivers/dri/i965/brw_wm_surface_state.c  | 15 +++++++++++----
 src/mesa/drivers/dri/i965/gen7_wm_surface_state.c | 14 ++++++++++----
 src/mesa/drivers/dri/i965/intel_extensions.c      |  1 +
 5 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/docs/GL3.txt b/docs/GL3.txt
index c269f19..1b04cc1 100644
--- a/docs/GL3.txt
+++ b/docs/GL3.txt
@@ -157,7 +157,7 @@ ARB_robust_buffer_access_behavior                    not started
 ARB_shader_image_size                                not started
 ARB_shader_storage_buffer_object                     not started
 ARB_stencil_texturing                                not started
-ARB_texture_buffer_range                             DONE (nv50, nvc0)
+ARB_texture_buffer_range                             DONE (nv50, nvc0, i965)
 ARB_texture_query_levels                             DONE (i965)
 ARB_texture_storage_multisample                      DONE (i965)
 ARB_texture_view                                     not started
diff --git a/src/mesa/drivers/dri/i965/brw_context.c b/src/mesa/drivers/dri/i965/brw_context.c
index dee8032..e2bf913 100644
--- a/src/mesa/drivers/dri/i965/brw_context.c
+++ b/src/mesa/drivers/dri/i965/brw_context.c
@@ -249,6 +249,7 @@ brw_initialize_context_constants(struct brw_context *brw)
     *      the element in the buffer."
     */
    ctx->Const.UniformBufferOffsetAlignment = 1;
+   ctx->Const.TextureBufferOffsetAlignment = 1;
 
    ctx->Const.ForceGLSLExtensionsWarn =
       driQueryOptionb(&brw->optionCache, "force_glsl_extensions_warn");
diff --git a/src/mesa/drivers/dri/i965/brw_wm_surface_state.c b/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
index faebc3c..f0f24f8 100644
--- a/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
+++ b/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
@@ -232,20 +232,27 @@ brw_update_buffer_texture_surface(struct gl_context *ctx,
    struct gl_texture_object *tObj = ctx->Texture.Unit[unit]._Current;
    struct intel_buffer_object *intel_obj =
       intel_buffer_object(tObj->BufferObject);
-   drm_intel_bo *bo = intel_obj ? intel_obj->buffer : NULL;
+   uint32_t size = tObj->BufferSize;
+   drm_intel_bo *bo = NULL;
    gl_format format = tObj->_BufferObjectFormat;
    uint32_t brw_format = brw_format_for_mesa_format(format);
    int texel_size = _mesa_get_format_bytes(format);
-   int w = intel_obj ? intel_obj->Base.Size / texel_size : 0;
+
+   if (intel_obj) {
+      bo = intel_obj->buffer;
+      size = MIN2(size, intel_obj->Base.Size);
+   }
 
    if (brw_format == 0 && format != MESA_FORMAT_RGBA_FLOAT32) {
       _mesa_problem(NULL, "bad format %s for texture buffer\n",
 		    _mesa_get_format_name(format));
    }
 
-   gen4_emit_buffer_surface_state(brw, surf_offset, bo, 0,
+   gen4_emit_buffer_surface_state(brw, surf_offset, bo,
+                                  tObj->BufferOffset,
                                   brw_format,
-                                  w, texel_size);
+                                  size / texel_size,
+                                  texel_size);
 }
 
 static void
diff --git a/src/mesa/drivers/dri/i965/gen7_wm_surface_state.c b/src/mesa/drivers/dri/i965/gen7_wm_surface_state.c
index 564ac76..c18593a 100644
--- a/src/mesa/drivers/dri/i965/gen7_wm_surface_state.c
+++ b/src/mesa/drivers/dri/i965/gen7_wm_surface_state.c
@@ -274,7 +274,14 @@ gen7_update_buffer_texture_surface(struct gl_context *ctx,
    struct gl_texture_object *tObj = ctx->Texture.Unit[unit]._Current;
    struct intel_buffer_object *intel_obj =
       intel_buffer_object(tObj->BufferObject);
-   drm_intel_bo *bo = intel_obj ? intel_obj->buffer : NULL;
+   uint32_t size = tObj->BufferSize;
+   drm_intel_bo *bo = NULL;
+
+   if (intel_obj) {
+      bo = intel_obj->buffer;
+      size = MIN2(size, intel_obj->Base.Size);
+   }
+
    gl_format format = tObj->_BufferObjectFormat;
 
    uint32_t surface_format = brw_format_for_mesa_format(format);
@@ -284,14 +291,13 @@ gen7_update_buffer_texture_surface(struct gl_context *ctx,
    }
 
    int texel_size = _mesa_get_format_bytes(format);
-   int w = intel_obj ? intel_obj->Base.Size / texel_size : 0;
 
    gen7_emit_buffer_surface_state(brw,
                                   surf_offset,
                                   bo,
-                                  0,
+                                  tObj->BufferOffset,
                                   surface_format,
-                                  w,
+                                  size / texel_size,
                                   texel_size,
                                   0 /* mocs */);
 }
diff --git a/src/mesa/drivers/dri/i965/intel_extensions.c b/src/mesa/drivers/dri/i965/intel_extensions.c
index 6f024b4..272d8e3 100644
--- a/src/mesa/drivers/dri/i965/intel_extensions.c
+++ b/src/mesa/drivers/dri/i965/intel_extensions.c
@@ -144,6 +144,7 @@ intelInitExtensions(struct gl_context *ctx)
       ctx->Extensions.ARB_shading_language_420pack = true;
       ctx->Extensions.ARB_texture_buffer_object = true;
       ctx->Extensions.ARB_texture_buffer_object_rgb32 = true;
+      ctx->Extensions.ARB_texture_buffer_range = true;
       ctx->Extensions.ARB_texture_cube_map_array = true;
       ctx->Extensions.OES_depth_texture_cube_map = true;
       ctx->Extensions.ARB_shading_language_packing = true;
-- 
1.8.4.rc3