r300g: add support for 3D NPOT textures without mipmapping

The driver actually creates a 3D texture aligned to POT and does all
the magic with texture coordinates in the fragment shader. It first
emulates REPEAT and MIRRORED wrap modes in the fragment shader to get
the coordinates into the range [0, 1]. (already done for 2D NPOT)
Then it scales them to get the coordinates of the NPOT subtexture.

NPOT textures are now less of a lie and we can at least display
something meaningful even for the 3D ones.

Supported wrap modes:
- REPEAT
- MIRRORED_REPEAT
- CLAMP_TO_EDGE (NEAREST filtering only)
- MIRROR_CLAMP_TO_EDGE (NEAREST filtering only)
- The behavior of other CLAMP modes is undefined on borders, but they usually
  give results very close to CLAMP_TO_EDGE with mirroring working perfectly.

This fixes:
- piglit/fbo-3d
- piglit/tex3d-npot

1 files changed, 23 insertions, 12 deletions

diff --git a/src/gallium/drivers/r300/r300_texture_desc.c b/src/gallium/drivers/r300/r300_texture_desc.c
index 6a1030f8ee..a49029e1e9 100644
--- a/src/gallium/drivers/r300/r300_texture_desc.c
+++ b/src/gallium/drivers/r300/r300_texture_desc.c
@@ -91,9 +91,9 @@ static boolean r300_texture_macro_switch(struct r300_texture_desc *desc,
     tile = r300_get_pixel_alignment(desc->b.b.format, desc->b.b.nr_samples,
                                     desc->microtile, R300_BUFFER_TILED, dim);
     if (dim == DIM_WIDTH) {
-        texdim = u_minify(desc->b.b.width0, level);
+        texdim = u_minify(desc->width0, level);
     } else {
-        texdim = u_minify(desc->b.b.height0, level);
+        texdim = u_minify(desc->height0, level);
     }
 
     /* See TX_FILTER1_n.MACRO_SWITCH. */
@@ -124,7 +124,7 @@ static unsigned r300_texture_get_stride(struct r300_screen *screen,
         return 0;
     }
 
-    width = u_minify(desc->b.b.width0, level);
+    width = u_minify(desc->width0, level);
 
     if (util_format_is_plain(desc->b.b.format)) {
         tile_width = r300_get_pixel_alignment(desc->b.b.format,
@@ -172,7 +172,7 @@ static unsigned r300_texture_get_nblocksy(struct r300_texture_desc *desc,
 {
     unsigned height, tile_height;
 
-    height = u_minify(desc->b.b.height0, level);
+    height = u_minify(desc->height0, level);
 
     if (util_format_is_plain(desc->b.b.format)) {
         tile_height = r300_get_pixel_alignment(desc->b.b.format,
@@ -237,7 +237,7 @@ static void r300_texture_3d_fix_mipmapping(struct r300_screen *screen,
                     r300_texture_get_nblocksy(desc, i, FALSE);
         }
 
-        size *= desc->b.b.depth0;
+        size *= desc->depth0;
         desc->size_in_bytes = size;
     }
 }
@@ -292,7 +292,7 @@ static void r300_setup_miptree(struct r300_screen *screen,
         if (base->target == PIPE_TEXTURE_CUBE)
             size = layer_size * 6;
         else
-            size = layer_size * u_minify(base->depth0, i);
+            size = layer_size * u_minify(desc->depth0, i);
 
         desc->offset_in_bytes[i] = desc->size_in_bytes;
         desc->size_in_bytes = desc->offset_in_bytes[i] + size;
@@ -303,8 +303,8 @@ static void r300_setup_miptree(struct r300_screen *screen,
 
         SCREEN_DBG(screen, DBG_TEXALLOC, "r300: Texture miptree: Level %d "
                 "(%dx%dx%d px, pitch %d bytes) %d bytes total, macrotiled %s\n",
-                i, u_minify(base->width0, i), u_minify(base->height0, i),
-                u_minify(base->depth0, i), stride, desc->size_in_bytes,
+                i, u_minify(desc->width0, i), u_minify(desc->height0, i),
+                u_minify(desc->depth0, i), stride, desc->size_in_bytes,
                 desc->macrotile[i] ? "TRUE" : "FALSE");
     }
 }
@@ -313,14 +313,14 @@ static void r300_setup_flags(struct r300_texture_desc *desc)
 {
     desc->uses_stride_addressing =
         !util_is_power_of_two(desc->b.b.width0) ||
-        !util_is_power_of_two(desc->b.b.height0) ||
         (desc->stride_in_bytes_override &&
          stride_to_width(desc->b.b.format,
                          desc->stride_in_bytes_override) != desc->b.b.width0);
 
     desc->is_npot =
         desc->uses_stride_addressing ||
-        !util_is_power_of_two(desc->b.b.height0);
+        !util_is_power_of_two(desc->b.b.height0) ||
+        !util_is_power_of_two(desc->b.b.depth0);
 }
 
 static void r300_setup_cbzb_flags(struct r300_screen *rscreen,
@@ -416,9 +416,21 @@ boolean r300_texture_desc_init(struct r300_screen *rscreen,
 {
     desc->b.b = *base;
     desc->b.b.screen = &rscreen->screen;
-
     desc->stride_in_bytes_override = stride_in_bytes_override;
+    desc->width0 = base->width0;
+    desc->height0 = base->height0;
+    desc->depth0 = base->depth0;
+
+    r300_setup_flags(desc);
+
+    /* Align a 3D NPOT texture to POT. */
+    if (base->target == PIPE_TEXTURE_3D && desc->is_npot) {
+        desc->width0 = util_next_power_of_two(desc->width0);
+        desc->height0 = util_next_power_of_two(desc->height0);
+        desc->depth0 = util_next_power_of_two(desc->depth0);
+    }
 
+    /* Setup tiling. */
     if (microtile == R300_BUFFER_SELECT_LAYOUT ||
         macrotile == R300_BUFFER_SELECT_LAYOUT) {
         r300_setup_tiling(rscreen, desc);
@@ -428,7 +440,6 @@ boolean r300_texture_desc_init(struct r300_screen *rscreen,
         assert(desc->b.b.last_level == 0);
     }
 
-    r300_setup_flags(desc);
     r300_setup_cbzb_flags(rscreen, desc);
 
     /* Setup the miptree description. */