Export API for uploading a tex subregion from a CoglBuffer

This exposes 2 experimental functions that make it possible to upload a
subregion of a texture from a CoglBuffer by first wrapping the buffer as
a CoglBitmap and then allowing uploading of a subregion from a
CoglBitmap. The new functions are:

cogl_bitmap_new_from_buffer() and
cogl_texture_set_region_from_bitmap()

Actually for now we are exporting this API for practical reasons since
we already had this API internally and it enables a specific feature
that was requested, but it is worth nothing that it's quite likely we
will replace these with functions that don't involve the CoglBitmap API
at some point.

For reference: The CoglBitmap API was actually removed from the 2.0
experimental API reference manual some time ago because the hope was
that we'd come up with a neater replacement. It doesn't seem entirely
clear what the scope of the CoglBitmap api is so it has became a bit of
a dumping ground.  CoglBitmap is used for image loading, as a means to
represent the layout of image data and also internally deals with format
conversions.

Note: Because we are avoiding including CoglBitmap as part of the 2.0
API these functions aren't currently included in the 2.0 reference
manual.

Reviewed-by: Neil Roberts <neil@linux.intel.com>

9 files changed, 176 insertions, 130 deletions

diff --git a/cogl/cogl-atlas-texture.c b/cogl/cogl-atlas-texture.c
index 3b87d4ce..986707f4 100644
--- a/cogl/cogl-atlas-texture.c
+++ b/cogl/cogl-atlas-texture.c
@@ -437,52 +437,52 @@ _cogl_atlas_texture_set_region_with_border (CoglAtlasTexture *atlas_tex,
   CoglAtlas *atlas = atlas_tex->atlas;
 
   /* Copy the central data */
-  if (!_cogl_texture_set_region_from_bitmap (atlas->texture,
-                                             src_x, src_y,
-                                             dst_x + atlas_tex->rectangle.x + 1,
-                                             dst_y + atlas_tex->rectangle.y + 1,
-                                             dst_width,
-                                             dst_height,
-                                             bmp))
+  if (!cogl_texture_set_region_from_bitmap (atlas->texture,
+                                            src_x, src_y,
+                                            dst_x + atlas_tex->rectangle.x + 1,
+                                            dst_y + atlas_tex->rectangle.y + 1,
+                                            dst_width,
+                                            dst_height,
+                                            bmp))
     return FALSE;
 
   /* Update the left edge pixels */
   if (dst_x == 0 &&
-      !_cogl_texture_set_region_from_bitmap (atlas->texture,
-                                             src_x, src_y,
-                                             atlas_tex->rectangle.x,
-                                             dst_y + atlas_tex->rectangle.y + 1,
-                                             1, dst_height,
-                                             bmp))
+      !cogl_texture_set_region_from_bitmap (atlas->texture,
+                                            src_x, src_y,
+                                            atlas_tex->rectangle.x,
+                                            dst_y + atlas_tex->rectangle.y + 1,
+                                            1, dst_height,
+                                            bmp))
     return FALSE;
   /* Update the right edge pixels */
   if (dst_x + dst_width == atlas_tex->rectangle.width - 2 &&
-      !_cogl_texture_set_region_from_bitmap (atlas->texture,
-                                             src_x + dst_width - 1, src_y,
-                                             atlas_tex->rectangle.x +
-                                             atlas_tex->rectangle.width - 1,
-                                             dst_y + atlas_tex->rectangle.y + 1,
-                                             1, dst_height,
-                                             bmp))
+      !cogl_texture_set_region_from_bitmap (atlas->texture,
+                                            src_x + dst_width - 1, src_y,
+                                            atlas_tex->rectangle.x +
+                                            atlas_tex->rectangle.width - 1,
+                                            dst_y + atlas_tex->rectangle.y + 1,
+                                            1, dst_height,
+                                            bmp))
     return FALSE;
   /* Update the top edge pixels */
   if (dst_y == 0 &&
-      !_cogl_texture_set_region_from_bitmap (atlas->texture,
-                                             src_x, src_y,
-                                             dst_x + atlas_tex->rectangle.x + 1,
-                                             atlas_tex->rectangle.y,
-                                             dst_width, 1,
-                                             bmp))
+      !cogl_texture_set_region_from_bitmap (atlas->texture,
+                                            src_x, src_y,
+                                            dst_x + atlas_tex->rectangle.x + 1,
+                                            atlas_tex->rectangle.y,
+                                            dst_width, 1,
+                                            bmp))
     return FALSE;
   /* Update the bottom edge pixels */
   if (dst_y + dst_height == atlas_tex->rectangle.height - 2 &&
-      !_cogl_texture_set_region_from_bitmap (atlas->texture,
-                                             src_x, src_y + dst_height - 1,
-                                             dst_x + atlas_tex->rectangle.x + 1,
-                                             atlas_tex->rectangle.y +
-                                             atlas_tex->rectangle.height - 1,
-                                             dst_width, 1,
-                                             bmp))
+      !cogl_texture_set_region_from_bitmap (atlas->texture,
+                                            src_x, src_y + dst_height - 1,
+                                            dst_x + atlas_tex->rectangle.x + 1,
+                                            atlas_tex->rectangle.y +
+                                            atlas_tex->rectangle.height - 1,
+                                            dst_width, 1,
+                                            bmp))
     return FALSE;
 
   return TRUE;
@@ -526,11 +526,11 @@ _cogl_atlas_texture_set_region (CoglTexture    *tex,
     }
   else
     /* Otherwise we can just forward on to the sub texture */
-    return _cogl_texture_set_region_from_bitmap (atlas_tex->sub_texture,
-                                                 src_x, src_y,
-                                                 dst_x, dst_y,
-                                                 dst_width, dst_height,
-                                                 bmp);
+    return cogl_texture_set_region_from_bitmap (atlas_tex->sub_texture,
+                                                src_x, src_y,
+                                                dst_x, dst_y,
+                                                dst_width, dst_height,
+                                                bmp);
 }
 
 static CoglPixelFormat
diff --git a/cogl/cogl-bitmap-private.h b/cogl/cogl-bitmap-private.h
index 3df519f9..78962bf0 100644
--- a/cogl/cogl-bitmap-private.h
+++ b/cogl/cogl-bitmap-private.h
@@ -83,17 +83,6 @@ _cogl_bitmap_new_shared (CoglBitmap      *shared_bmp,
                          int              height,
                          int              rowstride);
 
-/* This creates a cogl bitmap that internally references a pixel
-   array. The data is not copied. _cogl_bitmap_map will divert to
-   mapping the pixel array */
-CoglBitmap *
-_cogl_bitmap_new_from_buffer (CoglBuffer      *buffer,
-                              CoglPixelFormat  format,
-                              int              width,
-                              int              height,
-                              int              rowstride,
-                              int              offset);
-
 gboolean
 _cogl_bitmap_can_convert (CoglPixelFormat src, CoglPixelFormat dst);
 
diff --git a/cogl/cogl-bitmap.c b/cogl/cogl-bitmap.c
index 88ad073b..781e6f8d 100644
--- a/cogl/cogl-bitmap.c
+++ b/cogl/cogl-bitmap.c
@@ -327,12 +327,12 @@ cogl_bitmap_new_from_file (const char  *filename,
 }
 
 CoglBitmap *
-_cogl_bitmap_new_from_buffer (CoglBuffer      *buffer,
-                              CoglPixelFormat  format,
-                              int              width,
-                              int              height,
-                              int              rowstride,
-                              int              offset)
+cogl_bitmap_new_from_buffer (CoglBuffer *buffer,
+                             CoglPixelFormat format,
+                             int width,
+                             int height,
+                             int rowstride,
+                             int offset)
 {
   CoglBitmap *bmp;
 
diff --git a/cogl/cogl-bitmap.h b/cogl/cogl-bitmap.h
index 1983802b..958327d7 100644
--- a/cogl/cogl-bitmap.h
+++ b/cogl/cogl-bitmap.h
@@ -29,6 +29,7 @@
 #define __COGL_BITMAP_H__
 
 #include <cogl/cogl-types.h>
+#include <cogl/cogl-buffer.h>
 
 G_BEGIN_DECLS
 
@@ -62,6 +63,37 @@ CoglBitmap *
 cogl_bitmap_new_from_file (const char *filename,
                            GError **error);
 
+#if defined (COGL_ENABLE_EXPERIMENTAL_API)
+
+#define cogl_bitmap_new_from_buffer cogl_bitmap_new_from_buffer_EXP
+/**
+ * cogl_bitmap_new_from_buffer:
+ * @buffer: A #CoglBuffer containing image data
+ * @format: The #CoglPixelFormat defining the format of the image data
+ *          in the given @buffer.
+ * @width: The width of the image data in the given @buffer.
+ * @height: The height of the image data in the given @buffer.
+ * @rowstride: The rowstride in bytes of the image data in the given @buffer.
+ * @offset: The offset into the given @buffer to the first pixel that
+ *          should be considered part of the #CoglBitmap.
+ *
+ * Wraps some image data that has been uploaded into a #CoglBuffer as
+ * a #CoglBitmap. The data is not copied in this process.
+ *
+ * Return value: a #CoglBitmap encapsulating the given @buffer.
+ *
+ * Since: 1.8
+ * Stability: unstable
+ */
+CoglBitmap *
+cogl_bitmap_new_from_buffer (CoglBuffer *buffer,
+                             CoglPixelFormat format,
+                             int width,
+                             int height,
+                             int rowstride,
+                             int offset);
+#endif
+
 /**
  * cogl_bitmap_get_size_from_file:
  * @filename: the file to check
diff --git a/cogl/cogl-sub-texture.c b/cogl/cogl-sub-texture.c
index d00dcd5b..933a325b 100644
--- a/cogl/cogl-sub-texture.c
+++ b/cogl/cogl-sub-texture.c
@@ -409,12 +409,12 @@ _cogl_sub_texture_set_region (CoglTexture    *tex,
 {
   CoglSubTexture  *sub_tex = COGL_SUB_TEXTURE (tex);
 
-  return _cogl_texture_set_region_from_bitmap (sub_tex->full_texture,
-                                               src_x, src_y,
-                                               dst_x + sub_tex->sub_x,
-                                               dst_y + sub_tex->sub_y,
-                                               dst_width, dst_height,
-                                               bmp);
+  return cogl_texture_set_region_from_bitmap (sub_tex->full_texture,
+                                              src_x, src_y,
+                                              dst_x + sub_tex->sub_x,
+                                              dst_y + sub_tex->sub_y,
+                                              dst_width, dst_height,
+                                              bmp);
 }
 
 static CoglPixelFormat
diff --git a/cogl/cogl-texture-2d-sliced.c b/cogl/cogl-texture-2d-sliced.c
index 9f516e4e..0775277c 100644
--- a/cogl/cogl-texture-2d-sliced.c
+++ b/cogl/cogl-texture-2d-sliced.c
@@ -318,18 +318,18 @@ _cogl_texture_2d_sliced_set_waste (CoglTexture2DSliced *tex_2ds,
                                         NULL,
                                         NULL);
 
-          _cogl_texture_set_region_from_bitmap (slice_tex,
-                                                0, /* src_x */
-                                                0, /* src_y */
-                                                /* dst_x */
-                                                x_span->size - x_span->waste,
-                                                y_iter->intersect_start -
-                                                y_span->start, /* dst_y */
-                                                x_span->waste, /* dst_width */
-                                                /* dst_height */
-                                                y_iter->intersect_end -
-                                                y_iter->intersect_start,
-                                                waste_bmp);
+          cogl_texture_set_region_from_bitmap (slice_tex,
+                                               0, /* src_x */
+                                               0, /* src_y */
+                                               /* dst_x */
+                                               x_span->size - x_span->waste,
+                                               y_iter->intersect_start -
+                                               y_span->start, /* dst_y */
+                                               x_span->waste, /* dst_width */
+                                               /* dst_height */
+                                               y_iter->intersect_end -
+                                               y_iter->intersect_start,
+                                               waste_bmp);
 
           cogl_object_unref (waste_bmp);
         }
@@ -374,17 +374,17 @@ _cogl_texture_2d_sliced_set_waste (CoglTexture2DSliced *tex_2ds,
                                         NULL,
                                         NULL);
 
-          _cogl_texture_set_region_from_bitmap (slice_tex,
-                                                0, /* src_x */
-                                                0, /* src_y */
-                                                /* dst_x */
-                                                x_iter->intersect_start -
-                                                x_iter->pos,
-                                                /* dst_y */
-                                                y_span->size - y_span->waste,
-                                                copy_width, /* dst_width */
-                                                y_span->waste, /* dst_height */
-                                                waste_bmp);
+          cogl_texture_set_region_from_bitmap (slice_tex,
+                                               0, /* src_x */
+                                               0, /* src_y */
+                                               /* dst_x */
+                                               x_iter->intersect_start -
+                                               x_iter->pos,
+                                               /* dst_y */
+                                               y_span->size - y_span->waste,
+                                               copy_width, /* dst_width */
+                                               y_span->waste, /* dst_height */
+                                               waste_bmp);
 
           cogl_object_unref (waste_bmp);
         }
@@ -426,16 +426,16 @@ _cogl_texture_2d_sliced_upload_to_gl (CoglTexture2DSliced *tex_2ds,
           slice_tex = g_array_index (tex_2ds->slice_textures,
                                      CoglHandle, slice_num);
 
-          _cogl_texture_set_region_from_bitmap (slice_tex,
-                                                x_span->start, /* src x */
-                                                y_span->start, /* src y */
-                                                0, /* dst x */
-                                                0, /* dst y */
-                                                x_span->size -
-                                                x_span->waste, /* width */
-                                                y_span->size -
-                                                y_span->waste, /* height */
-                                                bmp);
+          cogl_texture_set_region_from_bitmap (slice_tex,
+                                               x_span->start, /* src x */
+                                               y_span->start, /* src y */
+                                               0, /* dst x */
+                                               0, /* dst y */
+                                               x_span->size -
+                                               x_span->waste, /* width */
+                                               y_span->size -
+                                               y_span->waste, /* height */
+                                               bmp);
 
           /* Set up a fake iterator that covers the whole slice */
           x_iter.intersect_start = x_span->start;
@@ -559,14 +559,14 @@ _cogl_texture_2d_sliced_upload_subregion_to_gl (CoglTexture2DSliced *tex_2ds,
           slice_tex = g_array_index (tex_2ds->slice_textures,
                                      CoglHandle, slice_num);
 
-          _cogl_texture_set_region_from_bitmap (slice_tex,
-                                                source_x,
-                                                source_y,
-                                                local_x, /* dst x */
-                                                local_y, /* dst y */
-                                                inter_w, /* width */
-                                                inter_h, /* height */
-                                                source_bmp);
+          cogl_texture_set_region_from_bitmap (slice_tex,
+                                               source_x,
+                                               source_y,
+                                               local_x, /* dst x */
+                                               local_y, /* dst y */
+                                               inter_w, /* width */
+                                               inter_h, /* height */
+                                               source_bmp);
 
           _cogl_texture_2d_sliced_set_waste (tex_2ds,
                                              source_bmp,
diff --git a/cogl/cogl-texture-private.h b/cogl/cogl-texture-private.h
index fa0d5791..767069a4 100644
--- a/cogl/cogl-texture-private.h
+++ b/cogl/cogl-texture-private.h
@@ -280,16 +280,6 @@ _cogl_texture_draw_and_read (CoglHandle   handle,
 gboolean
 _cogl_texture_is_foreign (CoglHandle handle);
 
-gboolean
-_cogl_texture_set_region_from_bitmap (CoglHandle    handle,
-                                      int           src_x,
-                                      int           src_y,
-                                      int           dst_x,
-                                      int           dst_y,
-                                      unsigned int  dst_width,
-                                      unsigned int  dst_height,
-                                      CoglBitmap   *bmp);
-
 void
 _cogl_texture_associate_framebuffer (CoglHandle handle,
                                      CoglFramebuffer *framebuffer);
diff --git a/cogl/cogl-texture.c b/cogl/cogl-texture.c
index 134e5f5b..165811f9 100644
--- a/cogl/cogl-texture.c
+++ b/cogl/cogl-texture.c
@@ -627,11 +627,11 @@ cogl_texture_new_from_buffer_EXP (CoglHandle          buffer,
     }
 
   /* Wrap the buffer into a bitmap */
-  bmp = _cogl_bitmap_new_from_buffer (cogl_buffer,
-                                      format,
-                                      width, height,
-                                      rowstride,
-                                      offset);
+  bmp = cogl_bitmap_new_from_buffer (cogl_buffer,
+                                     format,
+                                     width, height,
+                                     rowstride,
+                                     offset);
 
   texture = cogl_texture_new_from_bitmap (bmp, flags, internal_format);
 
@@ -852,14 +852,14 @@ _cogl_texture_ensure_non_quad_rendering (CoglHandle handle)
 }
 
 gboolean
-_cogl_texture_set_region_from_bitmap (CoglHandle    handle,
-                                      int           src_x,
-                                      int           src_y,
-                                      int           dst_x,
-                                      int           dst_y,
-                                      unsigned int  dst_width,
-                                      unsigned int  dst_height,
-                                      CoglBitmap   *bmp)
+cogl_texture_set_region_from_bitmap (CoglHandle handle,
+                                     int src_x,
+                                     int src_y,
+                                     int dst_x,
+                                     int dst_y,
+                                     unsigned int dst_width,
+                                     unsigned int dst_height,
+                                     CoglBitmap *bmp)
 {
   CoglTexture *tex = COGL_TEXTURE (handle);
   GLenum       closest_gl_format;
@@ -924,11 +924,11 @@ cogl_texture_set_region (CoglHandle       handle,
                                            NULL, /* destroy_fn */
                                            NULL); /* destroy_fn_data */
 
-  ret = _cogl_texture_set_region_from_bitmap (handle,
-                                              src_x, src_y,
-                                              dst_x, dst_y,
-                                              dst_width, dst_height,
-                                              source_bmp);
+  ret = cogl_texture_set_region_from_bitmap (handle,
+                                             src_x, src_y,
+                                             dst_x, dst_y,
+                                             dst_width, dst_height,
+                                             source_bmp);
 
   cogl_object_unref (source_bmp);
 
diff --git a/cogl/cogl-texture.h b/cogl/cogl-texture.h
index 93c1c3cb..41e6ee48 100644
--- a/cogl/cogl-texture.h
+++ b/cogl/cogl-texture.h
@@ -367,6 +367,41 @@ cogl_texture_set_region (CoglHandle       handle,
                          unsigned int     rowstride,
                          const guint8    *data);
 
+#if defined (COGL_ENABLE_EXPERIMENTAL_API)
+
+#define cogl_texture_set_region_from_bitmap \
+  cogl_texture_set_region_from_bitmap_EXP
+/**
+ * cogl_texture_set_region_from_bitmap:
+ * @handle: a #CoglHandle for a texture
+ * @src_x: upper left coordinate to use from the source bitmap.
+ * @src_y: upper left coordinate to use from the source bitmap
+ * @dst_x: upper left destination horizontal coordinate.
+ * @dst_y: upper left destination vertical coordinate.
+ * @dst_width: width of destination region to write.
+ * @dst_height: height of destination region to write.
+ * @bitmap: The source bitmap to read from
+ *
+ * Copies a specified source region from @bitmap to the position
+ * (@src_x, @src_y) of the given destination texture @handle.
+ *
+ * Return value: %TRUE if the subregion upload was successful, and
+ *   %FALSE otherwise
+ *
+ * Since: 1.8
+ * Stability: unstable
+ */
+gboolean
+cogl_texture_set_region_from_bitmap (CoglHandle handle,
+                                     int src_x,
+                                     int src_y,
+                                     int dst_x,
+                                     int dst_y,
+                                     unsigned int dst_width,
+                                     unsigned int dst_height,
+                                     CoglBitmap *bitmap);
+#endif
+
 /**
  * cogl_texture_new_from_sub_texture:
  * @full_texture: a #CoglHandle to an existing texture