Files
test/source/blender/imbuf
Sybren A. Stüvel b271475a9e ImBuf: Add error handling to IMB_indexer_open
Handle return value of `fread()` by printing an error and closing the
file when it cannot be read from. Not only is error handing a good idea,
it also prevents GCC from warning that the return value of `fread()`
should not be ignored:

```
.../blender/source/blender/imbuf/intern/indexer.c: In function ‘IMB_indexer_open’:
.../blender/source/blender/imbuf/intern/indexer.c:201:5: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  201 |     fread(&idx->entries[i].frameno, sizeof(int), 1, fp);
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.../blender/source/blender/imbuf/intern/indexer.c:202:5: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  202 |     fread(&idx->entries[i].seek_pos, sizeof(unsigned long long), 1, fp);
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.../blender/source/blender/imbuf/intern/indexer.c:203:5: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  203 |     fread(&idx->entries[i].seek_pos_dts, sizeof(unsigned long long), 1, fp);
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.../blender/source/blender/imbuf/intern/indexer.c:204:5: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  204 |     fread(&idx->entries[i].pts, sizeof(unsigned long long), 1, fp);
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
```

Differential Revision: https://developer.blender.org/D9916

Reviewed by: campbellbarton
2021-01-11 17:29:21 +01:00
..
2020-10-19 08:43:08 -07:00

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 what's easier 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 cmake you need to edit blender/source/blender/imbuf/CMakeLists.txt
and add in your additional files to source_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