Files
test/source/blender/imbuf
Bastien Montagne 59b2acc71b Make .blend file thumbnail reading simpler and more coherent, read/store them when reading in background mode.
Primary goal of this commit is to fix an annoying issue - when processing and saving .blend
files in background mode you lose their thumbnails, since it can only be generated with
an OpenGL context.

Solution to that is to read .blend thumbnail while reading .blend file (only done in background
mode currently), and store it in Main struct.

Also, this lead to removing .blend file reading code from thumb_blend (no need to have doublons).
We now have a small interface in regular reading code area, which keeps it reasonbaly light
by only reading/parsing header info, and first few BHead blocks.

This makes code reading .blend thumbnail about 3 to 4 times slower than previous highly specialized
one in blend_thumb.c, but overall thumbnail generation of a big .blend files folder only grows
of about 1%, think we can bare with it.

Finally, since thumbnail is now optionally stored in Main struct, it makes it easy to allow user
to define their own custom one (instead of auto-generated one). RNA API for this was not added though,
accessing that kind of .blend meta-data has to be rethought a bit on a bigger level first.

Reviewers: sergey, campbellbarton

Subscribers: Severin, psy-fi

Differential Revision: https://developer.blender.org/D1469
2015-08-27 16:00:46 +02:00
..
2015-04-08 10:38:19 +10:00
2015-08-06 13:03:07 +10:00

The following 4 steps to adding a new image format to blender, its
probably easiest to look at the png code for a clean clear example,
animation formats are a bit more complicated but very similar:

Step 1:
create a new file named after the format for example lets say we were
creating an openexr read/writer  use openexr.c
It should contain functions to match the following prototypes:

struct ImBuf *imb_loadopenexr(unsigned char *mem,int size,int flags);
/* Use one of the following depending on whats easyer for your file format */
short imb_saveopenexr(struct ImBuf *ibuf, FILE myfile, int flags);
short imb_saveopenexr(struct ImBuf *ibuf, char *myfile, int flags);

/* Used to test if its the correct format
int IMB_is_openexr(void *buf);

Step 2: 
Add your hooks to read and write the image format these go in
	writeimage.c and readimage.c  just look at how the others are done

Step 3: 
Add in IS_openexr to blender/source/blender/imbuf/IMB_imbuf_types.h
Add in R_openexr to source/blender/makesdna/DNA_scene_types.h

Step 4:
Add your hooks to the gui.
source/blender/src/buttons_scene.c
source/blender/src/toets.c
source/blender/src/writeimage.c

Step 5:
edit the following files:
blender/source/blender/imbuf/intern/util.c
blender/source/blender/src/filesel.c
blender/source/blender/src/screendump.c
and add your extension so that your format gets recognized in the thumbnails.

Step 6: 
Alter the build process:
For scons you need to edit blender/source/blender/imbuf/SConscript 
and add in your additional files to source_files.
For msvp you need to edit blender/projectfiles/blender/imbuf/BL_imbuf.dsp
and add in your additional files.
If you have any external library info you will also need to add that 
to the various build processes.

Step 7:
Its also good to add your image format to:
makepicstring in blender/source/blender/blenkernel/intern/image.c