Motivation / Problem

Palette remap was not applied to cursor sprites when using OpenGL.

Description

Change shader code to apply palette remap.

Limitations

Transparent palette remap is not implemented, but not used for cursor sprites. The shader code is also not very optimised, which should not pose a problem for the average pixel amount in a cursor sprite.

Checklist for review

Some things are not automated, and forgotten often. This list is a reminder for the reviewers.

• The bug fix is important enough to be backported? (label: 'backport requested')
• This PR affects the save game format? (label 'savegame upgrade')
• This PR affects the GS/AI API? (label 'needs review: Script API')
  • ai_changelog.hpp, gs_changelog.hpp need updating.
  • The compatibility wrappers (compat_*.nut) need updating.
• This PR affects the NewGRF API? (label 'needs review: NewGRF')
  • newgrf_debug_data.h may need updating.
  • PR must be added to API tracker