swrast: Replace ImageOffsets with an ImageSlices pointer.

This is a step toward allowing drivers to use their normal mapping paths,
instead of requiring that all slice mappings come from an aligned offset
from the first slice's map.

This incidentally fixes missing slice handling in FXT1 swrast.

v2: Use slice height helper function.

Reviewed-by: Kenneth Graunke <[email protected]>
Reviewed-by: Brian Paul <[email protected]>

1 files changed, 22 insertions, 21 deletions

diff --git a/src/mesa/swrast/s_texture.c b/src/mesa/swrast/s_texture.c
index 4d3cd0f8ce1..b0990a8cc30 100644
--- a/src/mesa/swrast/s_texture.c
+++ b/src/mesa/swrast/s_texture.c
@@ -88,23 +88,26 @@ _swrast_alloc_texture_image_buffer(struct gl_context *ctx,
                                    struct gl_texture_image *texImage)
 {
    struct swrast_texture_image *swImg = swrast_texture_image(texImage);
-   GLuint bytes = _mesa_format_image_size(texImage->TexFormat, texImage->Width,
-                                          texImage->Height, texImage->Depth);
+   GLuint bytesPerSlice;
+   GLuint slices = texture_slices(texImage);
    GLuint i;
 
    if (!_swrast_init_texture_image(texImage))
       return GL_FALSE;
 
+   bytesPerSlice = _mesa_format_image_size(texImage->TexFormat, texImage->Width,
+                                           _swrast_teximage_slice_height(texImage), 1);
+
    assert(!swImg->Buffer);
-   swImg->Buffer = _mesa_align_malloc(bytes, 512);
+   swImg->Buffer = _mesa_align_malloc(bytesPerSlice * slices, 512);
    if (!swImg->Buffer)
       return GL_FALSE;
 
-   /* RowStride and ImageOffsets[] describe how to address texels in 'Data' */
+   /* RowStride and ImageSlices[] describe how to address texels in 'Data' */
    swImg->RowStride = texImage->Width;
 
-   for (i = 0; i < texture_slices(texImage); i++) {
-      swImg->ImageOffsets[i] = i * texImage->Width * texImage->Height;
+   for (i = 0; i < slices; i++) {
+      swImg->ImageSlices[i] = swImg->Buffer + bytesPerSlice * i;
    }
 
    return GL_TRUE;
@@ -114,7 +117,7 @@ _swrast_alloc_texture_image_buffer(struct gl_context *ctx,
 /**
  * Code that overrides ctx->Driver.AllocTextureImageBuffer may use this to
  * initialize the fields of swrast_texture_image without allocating the image
- * buffer or initializing RowStride or the contents of ImageOffsets.
+ * buffer or initializing RowStride or the contents of ImageSlices.
  *
  * Returns GL_TRUE on success, GL_FALSE on memory allocation failure.
  */
@@ -143,9 +146,9 @@ _swrast_init_texture_image(struct gl_texture_image *texImage)
       swImg->DepthScale = (GLfloat) texImage->Depth;
    }
 
-   assert(!swImg->ImageOffsets);
-   swImg->ImageOffsets = malloc(texture_slices(texImage) * sizeof(GLuint));
-   if (!swImg->ImageOffsets)
+   assert(!swImg->ImageSlices);
+   swImg->ImageSlices = calloc(texture_slices(texImage), sizeof(void *));
+   if (!swImg->ImageSlices)
       return GL_FALSE;
 
    return GL_TRUE;
@@ -165,8 +168,8 @@ _swrast_free_texture_image_buffer(struct gl_context *ctx,
       swImage->Buffer = NULL;
    }
 
-   free(swImage->ImageOffsets);
-   swImage->ImageOffsets = NULL;
+   free(swImage->ImageSlices);
+   swImage->ImageSlices = NULL;
 }
 
 
@@ -227,17 +230,15 @@ _swrast_map_teximage(struct gl_context *ctx,
       *mapOut = NULL;
       return;
    }
-      
-   map = swImage->Buffer;
+
+   /* This function can only be used with a swrast-allocated buffer, in which
+    * case ImageSlices is populated with pointers into Buffer.
+    */
+   assert(swImage->Buffer);
+   assert(swImage->Buffer == swImage->ImageSlices[0]);
 
    assert(slice < texture_slices(texImage));
-   if (slice != 0) {
-      GLuint sliceSize = _mesa_format_image_size(texImage->TexFormat,
-                                                 texImage->Width,
-                                                 _swrast_teximage_slice_height(texImage),
-                                                 1);
-      map += slice * sliceSize;
-   }
+   map = swImage->ImageSlices[slice];
 
    /* apply x/y offset to map address */
    map += stride * (y / bh) + texelSize * (x / bw);