mesa: add MaxNumLevels to gl_texture_image, remove MaxLog2

MaxLog2 led to bugs, because it didn't work well with 1D and 3D textures.

NOTE: This is a candidate for the stable branches.

v2: correct the comment at MaxNumlevels

Reviewed-by: Brian Paul <[email protected]>
Reviewed-by: Dave Airlie <[email protected]>

3 files changed, 45 insertions, 2 deletions

diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index b99e7104424..da72da9d106 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -1203,7 +1203,8 @@ struct gl_texture_image
    GLuint WidthLog2;		/**< = log2(Width2) */
    GLuint HeightLog2;		/**< = log2(Height2) */
    GLuint DepthLog2;		/**< = log2(Depth2) */
-   GLuint MaxLog2;		/**< = MAX(WidthLog2, HeightLog2) */
+   GLuint MaxNumLevels;		/**< = maximum possible number of mipmap
+                                       levels, computed from the dimensions */
 
    struct gl_texture_object *TexObject;  /**< Pointer back to parent object */
    GLuint Level;                /**< Which mipmap level am I? */
diff --git a/src/mesa/main/teximage.c b/src/mesa/main/teximage.c
index 678833ec5ee..0850ef1110c 100644
--- a/src/mesa/main/teximage.c
+++ b/src/mesa/main/teximage.c
@@ -1027,6 +1027,43 @@ _mesa_get_texture_dimensions(GLenum target)
 }
 
 
+/**
+ * Return the maximum number of mipmap levels for the given target
+ * and the dimensions.
+ * The dimensions are expected not to include the border.
+ */
+GLsizei
+_mesa_get_tex_max_num_levels(GLenum target, GLsizei width, GLsizei height,
+                             GLsizei depth)
+{
+   GLsizei size;
+
+   switch (target) {
+   case GL_TEXTURE_1D:
+   case GL_TEXTURE_1D_ARRAY:
+      size = width;
+      break;
+   case GL_TEXTURE_CUBE_MAP:
+   case GL_TEXTURE_CUBE_MAP_ARRAY:
+      ASSERT(width == height);
+      size = width;
+      break;
+   case GL_TEXTURE_2D:
+   case GL_TEXTURE_2D_ARRAY:
+      size = MAX2(width, height);
+      break;
+   case GL_TEXTURE_3D:
+      size = MAX3(width, height, depth);
+      break;
+   case GL_TEXTURE_RECTANGLE:
+      return 1;
+   default:
+      assert(0);
+      return 1;
+   }
+
+   return _mesa_logbase2(size) + 1;
+}
 
 
 #if 000 /* not used anymore */
@@ -1214,7 +1251,9 @@ _mesa_init_teximage_fields(struct gl_context *ctx,
                     target);
    }
 
-   img->MaxLog2 = MAX2(img->WidthLog2, img->HeightLog2);
+   img->MaxNumLevels =
+      _mesa_get_tex_max_num_levels(target,
+                                   img->Width2, img->Height2, img->Depth2);
    img->TexFormat = format;
 }
 
diff --git a/src/mesa/main/teximage.h b/src/mesa/main/teximage.h
index ca4b8c86632..e136faa6d13 100644
--- a/src/mesa/main/teximage.h
+++ b/src/mesa/main/teximage.h
@@ -138,6 +138,9 @@ _mesa_tex_target_to_face(GLenum target);
 extern GLint
 _mesa_get_texture_dimensions(GLenum target);
 
+extern GLsizei
+_mesa_get_tex_max_num_levels(GLenum target, GLsizei width, GLsizei height,
+                             GLsizei depth);
 
 extern GLboolean
 _mesa_legal_texture_dimensions(struct gl_context *ctx, GLenum target,