1
0
Fork 0
mirror of https://github.com/luanti-org/luanti.git synced 2025-06-27 16:36:03 +00:00

Fix rendering regression with TGA type 1 files with BGRA8 color (#15402)

TGA uses BGR(A)8, stored in memory in that order. Irrlicht typically expects 0xAARRGGBB, which depends on endianness.
(This means that on little endian, no [B][G][R][A] -> 0xAARRGGBB conversion needs to be done, but Irrlicht was swapping the bytes.)

This makes both conversion functions consistently convert from [B][G][R]([A]) to 0xAARRGGBB (SColor), documents them properly and moves them to CImageLoaderTGA.cpp
so no poor soul shall be fooled by them in the near future.

---------

Co-authored-by: Ælla Chiana Moskopp <erle@dieweltistgarnichtso.net>
This commit is contained in:
Lars Müller 2024-11-19 13:37:05 +01:00 committed by GitHub
parent 138052adfc
commit 15e8f9e6a0
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
4 changed files with 32 additions and 33 deletions

View file

@ -7,6 +7,15 @@
#include "os.h"
#include "irrString.h"
// Warning: The naming of Irrlicht color formats
// is not consistent regarding actual component order in memory.
// E.g. in CImage, ECF_R8G8B8 is handled per-byte and stored as [R][G][B] in memory
// while ECF_A8R8G8B8 is handled as an u32 0xAARRGGBB so [B][G][R][A] (little endian) in memory.
// The conversions suffer from the same inconsistencies, e.g.
// convert_R8G8B8toA8R8G8B8 converts [R][G][B] into 0xFFRRGGBB = [B][G][R][FF] (little endian);
// convert_A1R5G5B5toR8G8B8 converts 0bARRRRRGGGGGBBBBB into [R][G][B].
// This also means many conversions may be broken on big endian.
namespace irr
{
namespace video
@ -393,19 +402,6 @@ void CColorConverter::convert_R8G8B8toA1R5G5B5(const void *sP, s32 sN, void *dP)
}
}
void CColorConverter::convert_B8G8R8toA8R8G8B8(const void *sP, s32 sN, void *dP)
{
u8 *sB = (u8 *)sP;
u32 *dB = (u32 *)dP;
for (s32 x = 0; x < sN; ++x) {
*dB = 0xff000000 | (sB[2] << 16) | (sB[1] << 8) | sB[0];
sB += 3;
++dB;
}
}
void CColorConverter::convert_A8R8G8B8toR8G8B8A8(const void *sP, s32 sN, void *dP)
{
const u32 *sB = (const u32 *)sP;
@ -428,22 +424,6 @@ void CColorConverter::convert_A8R8G8B8toA8B8G8R8(const void *sP, s32 sN, void *d
}
}
void CColorConverter::convert_B8G8R8A8toA8R8G8B8(const void *sP, s32 sN, void *dP)
{
u8 *sB = (u8 *)sP;
u8 *dB = (u8 *)dP;
for (s32 x = 0; x < sN; ++x) {
dB[0] = sB[3];
dB[1] = sB[2];
dB[2] = sB[1];
dB[3] = sB[0];
sB += 4;
dB += 4;
}
}
void CColorConverter::convert_R8G8B8toB8G8R8(const void *sP, s32 sN, void *dP)
{
u8 *sB = (u8 *)sP;