[texture][rlgl] DrawTexturePro() rendering issues for rotated uneven textures (e.g. 3x3 pixels)

[abflett]

I'm experiencing graphical issues when using DrawTexturePro in Raylib for rendering uneven textures, specifically 3x3 textures. When rotating these textures at a center origin, particularly in 90-degree intervals, the output appears misaligned, leading to an incorrect rendering order (e.g., pixels are shifted, resulting in a display where pixels "abc" appear as "cab").

This issue is particularly noticeable with odd-sized textures. When the texture's origin is centered for rotation, the graphical glitches manifest as subpixel shifts that disrupt the intended visual alignment. It seems that anything other than 90-degree rotations can exacerbate these rendering issues, resulting in further misalignment.

Ensuring that all textures are evenly divisible by 2 helps avoid these graphical anomalies. However, this limitation may impact the flexibility of designing sprites and textures in the future.

I would appreciate any guidance on potential fixes or adjustments in Raylib's rendering approach to resolve these graphical inconsistencies.

(4X zoom)

(Same blue texture rotated - don't mind the positions still using the offset padding from example below)

   DrawTexturePro(animation_handler->animation->texture_resource->texture,
                   animation_handler->animation->frames[animation_handler->frame_index],
                   (Rectangle){
                       (float)(int)position.x,
                       (float)(int)position.y,
                       width,
                       height},
                   (Vector2){width * 0.5f, height * 0.5f},
                   animation_handler->rotation,
                   WHITE);

(Fixed as shown with code below but rotates with a 1 pixel offset, which has been adjusted with position padding)

    DrawTexturePro(animation_handler->animation->texture_resource->texture,
                   animation_handler->animation->frames[animation_handler->frame_index],
                   (Rectangle){
                       (float)(int)position.x,
                       (float)(int)position.y,
                       width,
                       height},
                   (Vector2){(float)(int)(width * 0.5f), (float)(int)(height * 0.5f)},
                   animation_handler->rotation,
                   WHITE);

Windows 11, Nvidia 3060, default raylib settings.

[raysan5]

@abflett Wow! Good catch! It seems related to float rounding issues... but that's weird because float should give the most precision on results...

I'm checking the code but I can't see any point where precision can be lost so resulting numbers are directly provided to OpenGL API... so it makes me think it could be a driver/OpenGL issue...

At the moment I have no idea how it can be addressed from raylib side...

[abflett]

Here is a sample of the texture atlas if it helps: