mesa: Hide weirdness of 1D_ARRAY textures from Driver.CopyTexSubImage().

Intel had brokenness here, and I'd like to continue moving Mesa toward
hiding 1D_ARRAY's ridiculousness inside of the core, like we did with
MapTextureImage.  Fixes copyteximage 1D_ARRAY on intel.

There's still an impedance mismatch in meta when falling back to read and
texsubimage, since texsubimage expects coordinates into 1D_ARRAY as
(width, slice, 0) instead of (width, 0, slice).

v2: Fix offset of scanline reads from the source. (Thanks Brian!), replace
    dd.h comment with Paul's text and replace early exit with an assert.

Reviewed-by: Brian Paul <[email protected]> (v1)
Reviewed-by: Kenneth Graunke <[email protected]> (v1)
Reviewed-by: Paul Berry <[email protected]> (v1)

2 files changed, 42 insertions, 6 deletions

diff --git a/src/mesa/main/dd.h b/src/mesa/main/dd.h
index 6d564b25274..e2519780ab2 100644
--- a/src/mesa/main/dd.h
+++ b/src/mesa/main/dd.h
@@ -248,10 +248,16 @@ struct dd_function_table {
 
    /**
     * Called by glCopyTex[Sub]Image[123]D().
+    *
+    * This function should copy a rectangular region in the rb to a single
+    * destination slice, specified by @slice.  In the case of 1D array
+    * textures (where one GL call can potentially affect multiple destination
+    * slices), core mesa takes care of calling this function multiple times,
+    * once for each scanline to be copied.
     */
    void (*CopyTexSubImage)(struct gl_context *ctx, GLuint dims,
                            struct gl_texture_image *texImage,
-                           GLint xoffset, GLint yoffset, GLint zoffset,
+                           GLint xoffset, GLint yoffset, GLint slice,
                            struct gl_renderbuffer *rb,
                            GLint x, GLint y,
                            GLsizei width, GLsizei height);
diff --git a/src/mesa/main/teximage.c b/src/mesa/main/teximage.c
index 6f7fbc0d2a1..5226687ff92 100644
--- a/src/mesa/main/teximage.c
+++ b/src/mesa/main/teximage.c
@@ -3429,6 +3429,35 @@ get_copy_tex_image_source(struct gl_context *ctx, gl_format texFormat)
    }
 }
 
+static void
+copytexsubimage_by_slice(struct gl_context *ctx,
+                         struct gl_texture_image *texImage,
+                         GLuint dims,
+                         GLint xoffset, GLint yoffset, GLint zoffset,
+                         struct gl_renderbuffer *rb,
+                         GLint x, GLint y,
+                         GLsizei width, GLsizei height)
+{
+   if (texImage->TexObject->Target == GL_TEXTURE_1D_ARRAY) {
+      int slice;
+
+      /* For 1D arrays, we copy each scanline of the source rectangle into the
+       * next array slice.
+       */
+      assert(zoffset == 0);
+
+      for (slice = 0; slice < height; slice++) {
+         assert(yoffset + slice < texImage->Height);
+         ctx->Driver.CopyTexSubImage(ctx, 2, texImage,
+                                     xoffset, 0, yoffset + slice,
+                                     rb, x, y + slice, width, 1);
+      }
+   } else {
+      ctx->Driver.CopyTexSubImage(ctx, dims, texImage,
+                                  xoffset, yoffset, zoffset,
+                                  rb, x, y, width, height);
+   }
+}
 
 
 /**
@@ -3517,8 +3546,9 @@ copyteximage(struct gl_context *ctx, GLuint dims,
                struct gl_renderbuffer *srcRb =
                   get_copy_tex_image_source(ctx, texImage->TexFormat);
 
-               ctx->Driver.CopyTexSubImage(ctx, dims, texImage, dstX, dstY, dstZ,
-                                           srcRb, srcX, srcY, width, height);
+               copytexsubimage_by_slice(ctx, texImage, dims,
+                                        dstX, dstY, dstZ,
+                                        srcRb, srcX, srcY, width, height);
             }
 
             check_gen_mipmap(ctx, target, texObj, level);
@@ -3610,9 +3640,9 @@ copytexsubimage(struct gl_context *ctx, GLuint dims, GLenum target, GLint level,
          struct gl_renderbuffer *srcRb =
             get_copy_tex_image_source(ctx, texImage->TexFormat);
 
-         ctx->Driver.CopyTexSubImage(ctx, dims, texImage,
-                                     xoffset, yoffset, zoffset,
-                                     srcRb, x, y, width, height);
+         copytexsubimage_by_slice(ctx, texImage, dims,
+                                  xoffset, yoffset, zoffset,
+                                  srcRb, x, y, width, height);
 
          check_gen_mipmap(ctx, target, texObj, level);