SBmpLoadImage tried to get the size of the rest of the file incorrectly
by subtracting the current file position from the total size.
This was incorrect because file positions do not always begin at 0.
The only semi-portable way to get a size from file positions is to
subtract two file positions.
Single-player difficulty selection was implemented in a very hacky way.
Documents what's going on there and fixes a memory leak.
Memory leaks that this fixes looked like this:
```
Direct leak of 64 byte(s) in 1 object(s) allocated from:
#0 0x7f435b789f17 in operator new(unsigned long) (/lib/x86_64-linux-gnu/libasan.so.6+0xb1f17)
#1 0x5567766c62b8 in dvl::selgame_GameSelection_Select(int) ../SourceX/DiabloUI/selgame.cpp:163
#2 0x5567766d8ee8 in dvl::selhero_Load_Select(int) ../SourceX/DiabloUI/selhero.cpp:464
#3 0x5567766d6ed1 in dvl::selhero_List_Select(int) ../SourceX/DiabloUI/selhero.cpp:325
#4 0x556776692683 in dvl::UiFocusNavigationSelect() ../SourceX/DiabloUI/diabloui.cpp:396
#5 0x55677669158e in HandleMenuAction ../SourceX/DiabloUI/diabloui.cpp:223
#6 0x5567766917b9 in dvl::UiFocusNavigation(SDL_Event*) ../SourceX/DiabloUI/diabloui.cpp:277
#7 0x556776695dff in dvl::UiPollAndRender() ../SourceX/DiabloUI/diabloui.cpp:626
#8 0x5567766d94ef in UiSelHeroDialog ../SourceX/DiabloUI/selhero.cpp:512
#9 0x5567766d997f in dvl::UiSelHeroSingDialog(int (*)(int (*)(dvl::_uiheroinfo*)), int (*)(dvl::_uiheroinfo*), int (*)(dvl::_uiheroinfo*), void (*)(unsigned int, dvl::_uidefaultstats*), int*, char (*) [16], int*) ../SourceX/DiabloUI/selhero.cpp:547
#10 0x556776a44f45 in mainmenu_select_hero_dialog ../Source/mainmenu.cpp:98
#11 0x5567765f9f15 in SNetInitializeProvider ../SourceX/storm/storm_net.cpp:102
#12 0x556776c996b9 in multi_init_single ../Source/multi.cpp:826
#13 0x556776c98b1e in NetInit ../Source/multi.cpp:770
#14 0x5567767d0c0b in StartGame ../Source/diablo.cpp:375
#15 0x556776a4493d in mainmenu_init_menu ../Source/mainmenu.cpp:45
#16 0x556776a44c05 in mainmenu_single_player ../Source/mainmenu.cpp:61
#17 0x556776a454a9 in mainmenu_loop ../Source/mainmenu.cpp:152
#18 0x5567767d2892 in DiabloMain ../Source/diablo.cpp:602
#19 0x5567766e3c69 in main ../SourceX/main.cpp:34
#20 0x7f435a69ecb1 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x28cb1)
```
1. Moves right stick movement handler to run on every frame.
2. Changes hi-res accumulators to `float` to ensure they're always
incremented.
3. Avoid calling `SetCursorPos` within the same SDL tick:
this caused SDL to process all controller events before mouse events
(out-of-order).
(1) also makes right-stick-as-mouse work in `gmenu`.
Previously this was handle as part of `game_logic`, reducing
responsiveness and making it impossible to run where `game_logic`
isn't running, e.g. stores.
This fixes the following issues:
- Missing text shadows
- Missing button graphics
- White boarder
- Not responding to controller input
- Button not giving visual feedback
- Clicking anywhere cancles
`CelOutputBuffer` now contains an `SDL_Surface` and an `SDL_Rect`.
We now have access to SDL surface manipulation functions.
`gpBuffer` and `gpBufEnd` are completely gone 🧹
This results in some FPS loss (250 -> 195) recovered in a subsequent
commit.
Gleb Mazovetskiy
Anders Jenbo
Juliano Leal Goncalves
Yuri Pourre
Trihedraf
Yuri Pourre