[Mesa-dev] [PATCH 11/11] meta: Support GenerateMipmaps on 1DArray textures.

[Kenneth Graunke]

I don't know how many people care about this case, but it's easy enough
to do, so we may as well.  The tricky part is that for some reason Mesa
stores the number of array slices in Height, not Depth.

I thought the easiest way to handle that here was to make Height = 1
(the actual height), and srcDepth = srcImage->Height.  This requires
some munging when calling _mesa_prepare_mipmap_level, so I created a
wrapper that sorts it out for us.

Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
---
 src/mesa/drivers/common/meta_generate_mipmap.c | 42 ++++++++++++++++++++------
 1 file changed, 33 insertions(+), 9 deletions(-)

diff --git a/src/mesa/drivers/common/meta_generate_mipmap.c b/src/mesa/drivers/common/meta_generate_mipmap.c
index 9d352e9..3db073a 100644
--- a/src/mesa/drivers/common/meta_generate_mipmap.c
+++ b/src/mesa/drivers/common/meta_generate_mipmap.c
@@ -94,7 +94,7 @@ fallback_required(struct gl_context *ctx, GLenum target,
    GLenum status;
 
    /* check for fallbacks */
-   if (target == GL_TEXTURE_3D || target == GL_TEXTURE_1D_ARRAY) {
+   if (target == GL_TEXTURE_3D) {
       _mesa_perf_debug(ctx, MESA_DEBUG_SEVERITY_HIGH,
                        "glGenerateMipmap() to %s target\n",
                        _mesa_lookup_enum_by_nr(target));
@@ -163,6 +163,22 @@ _mesa_meta_glsl_generate_mipmap_cleanup(struct gen_mipmap_state *mipmap)
    _mesa_meta_blit_shader_table_cleanup(&mipmap->shaders);
 }
 
+static GLboolean
+prepare_mipmap_level(struct gl_context *ctx,
+                     struct gl_texture_object *texObj, GLuint level,
+                     GLsizei width, GLsizei height, GLsizei depth,
+                     GLenum intFormat, mesa_format format)
+{
+   if (texObj->Target == GL_TEXTURE_1D_ARRAY) {
+      /* Work around Mesa expecting the number of array slices in "height". */
+      height = depth;
+      depth = 1;
+   }
+
+   return _mesa_prepare_mipmap_level(ctx, texObj, level, width, height, depth,
+                                     0, intFormat, format);
+}
+
 /**
  * Called via ctx->Driver.GenerateMipmap()
  * Note: We don't yet support 3D textures, 1D/2D array textures or texture
@@ -276,8 +292,13 @@ _mesa_meta_GenerateMipmap(struct gl_context *ctx, GLenum target,
 
       /* src size */
       srcWidth = srcImage->Width;
-      srcHeight = srcImage->Height;
-      srcDepth = srcImage->Depth;
+      if (target == GL_TEXTURE_1D_ARRAY) {
+         srcHeight = 1;
+         srcDepth = srcImage->Height;
+      } else {
+         srcHeight = srcImage->Height;
+         srcDepth = srcImage->Depth;
+      }
 
       /* new dst size */
       dstWidth = minify(srcWidth, 1);
@@ -296,11 +317,10 @@ _mesa_meta_GenerateMipmap(struct gl_context *ctx, GLenum target,
       /* Set MaxLevel large enough to hold the new level when we allocate it */
       _mesa_TexParameteri(target, GL_TEXTURE_MAX_LEVEL, dstLevel);
 
-      if (!_mesa_prepare_mipmap_level(ctx, texObj, dstLevel,
-                                      dstWidth, dstHeight, dstDepth,
-                                      srcImage->Border,
-                                      srcImage->InternalFormat,
-                                      srcImage->TexFormat)) {
+      if (!prepare_mipmap_level(ctx, texObj, dstLevel,
+                                dstWidth, dstHeight, dstDepth,
+                                srcImage->InternalFormat,
+                                srcImage->TexFormat)) {
          /* All done.  We either ran out of memory or we would go beyond the
           * last valid level of an immutable texture if we continued.
           */
@@ -339,7 +359,11 @@ _mesa_meta_GenerateMipmap(struct gl_context *ctx, GLenum target,
          }
 
          assert(dstWidth == ctx->DrawBuffer->Width);
-         assert(dstHeight == ctx->DrawBuffer->Height);
+         if (target == GL_TEXTURE_1D_ARRAY) {
+            assert(dstHeight == 1);
+         } else {
+            assert(dstHeight == ctx->DrawBuffer->Height);
+         }
 
          _mesa_DrawArrays(GL_TRIANGLE_FAN, 0, 4);
       }
-- 
1.9.0