Changeset 1561 adds support for cameras that allow the subject distance override value to be > 65535. These cameras also use an infinity value of 0xFFFFFFFF (-1) rather than 0xFFFF (65535).
The previous CHDK code assumed the SD value was 16 bits and would limit the value being sent to a max of 65535. It also sent 65535 as the infinity value.
This change allows the limit to be overridden in platform_camera.h for each camera - the default unless overridden stays at 65535. The infinity value is now sent as 0xFFFFFFFF, for cameras that only expect a 16 bit value this should not change the behaviour.
Also added a MIN_DIST value which defaults to 0; but can also be overridden. This is used in the menu U/I to set the lowest value that can be selected.
Lastly the change includes an update to the menu U/I for SD override to increase the number of 'value factor' values for changing larger values. This also adds a special case 'Infinity' override that forces the camera to set the SD to infinity.
Implemented for G12, SX30, SX40 and IXUS310.
To see if other cameras need this do the following.
1. Override the CAMERA_MAX_DIST value in platform_camera.h to a very large value, e.g 1000000000 (this is required for the attached script). Rebuild CHDK and load on the camera.
2. Run the attached Lua script on the camera, which will display the min and max SD values on the camera screen.
Note, the script may return different values for 'max' when run on some cameras. It should be run 4-5 times and the largest value used.
Phil.
