i965: Define and initialize image parameter structure.

This will be used to pass image meta-data to the shader when we cannot
use typed surface reads and writes.  All entries except surface_idx
and size are otherwise unused and will get eliminated by the uniform
packing pass.  size will be used for bounds checking with some image
formats and will be useful for ARB_shader_image_size too.  surface_idx
is always used.

v2: Add CS support.  Move the image_params array back to
    brw_stage_prog_data.
v3: Improve documentation.

Reviewed-by: Topi Pohjolainen <[email protected]>
Reviewed-by: Jason Ekstrand <[email protected]>

1 files changed, 54 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_context.h b/src/mesa/drivers/dri/i965/brw_context.h
index 3aff9246db8..b851f3830a2 100644
--- a/src/mesa/drivers/dri/i965/brw_context.h
+++ b/src/mesa/drivers/dri/i965/brw_context.h
@@ -361,6 +361,7 @@ struct brw_stage_prog_data {
 
    GLuint nr_params;       /**< number of float params/constants */
    GLuint nr_pull_params;
+   unsigned nr_image_params;
 
    unsigned curb_read_length;
    unsigned total_scratch;
@@ -381,6 +382,59 @@ struct brw_stage_prog_data {
     */
    const gl_constant_value **param;
    const gl_constant_value **pull_param;
+
+   /**
+    * Image metadata passed to the shader as uniforms.  This is deliberately
+    * ignored by brw_stage_prog_data_compare() because its contents don't have
+    * any influence on program compilation.
+    */
+   struct brw_image_param *image_param;
+};
+
+/*
+ * Image metadata structure as laid out in the shader parameter
+ * buffer.  Entries have to be 16B-aligned for the vec4 back-end to be
+ * able to use them.  That's okay because the padding and any unused
+ * entries [most of them except when we're doing untyped surface
+ * access] will be removed by the uniform packing pass.
+ */
+#define BRW_IMAGE_PARAM_SURFACE_IDX_OFFSET      0
+#define BRW_IMAGE_PARAM_OFFSET_OFFSET           4
+#define BRW_IMAGE_PARAM_SIZE_OFFSET             8
+#define BRW_IMAGE_PARAM_STRIDE_OFFSET           12
+#define BRW_IMAGE_PARAM_TILING_OFFSET           16
+#define BRW_IMAGE_PARAM_SWIZZLING_OFFSET        20
+#define BRW_IMAGE_PARAM_SIZE                    24
+
+struct brw_image_param {
+   /** Surface binding table index. */
+   uint32_t surface_idx;
+
+   /** Offset applied to the X and Y surface coordinates. */
+   uint32_t offset[2];
+
+   /** Surface X, Y and Z dimensions. */
+   uint32_t size[3];
+
+   /** X-stride in bytes, Y-stride in pixels, horizontal slice stride in
+    * pixels, vertical slice stride in pixels.
+    */
+   uint32_t stride[4];
+
+   /** Log2 of the tiling modulus in the X, Y and Z dimension. */
+   uint32_t tiling[3];
+
+   /**
+    * Right shift to apply for bit 6 address swizzling.  Two different
+    * swizzles can be specified and will be applied one after the other.  The
+    * resulting address will be:
+    *
+    *  addr' = addr ^ ((1 << 6) & ((addr >> swizzling[0]) ^
+    *                              (addr >> swizzling[1])))
+    *
+    * Use \c 0xff if any of the swizzles is not required.
+    */
+   uint32_t swizzling[2];
 };
 
 /* Data about a particular attempt to compile a program.  Note that