[rlgl] Fix Not default Draw Mode breaking when changing texture

[maiconpintoabreu]

This PR is to fix the rlSetTexture as when you have different textures it will not override the mode that is default to GL_QUAD.
The fix is to check if the drawCounter has more then 1 and copy the previous mode to the new Draw.
If the developer is drawing a mix of Modes The rlSetTexture need to be after rlBegin.

Fix for the issue: #5142

RenderDoc tests:

[raysan5]

@maiconpintoabreu I can't remember at the moment if rlSetTexture() needs to be after rlBegin() or before but I wonder if everything still works on OpenGL 1.1, it could be sensible in that case...

This PR changes how it was designed originally... and I'm afraid it was structure that way for some reason... but it was so long ago that I can't remember...

[maiconpintoabreu]

@raysan5, this change does not change any OpenGL call, but I will try to test it on 1.1 and post the results later.
I did a diagram explaining the issues involved, maybe makes it more clear.

[maiconpintoabreu]

@maiconpintoabreu I can't remember at the moment if rlSetTexture() needs to be after rlBegin() or before but I wonder if everything still works on OpenGL 1.1, it could be sensible in that case...

This PR changes how it was designed originally... and I'm afraid it was structure that way for some reason... but it was so long ago that I can't remember...

Based on OpenGL 1.1 rlSetTexture() needs to be before rlBegin()
I will check if I can do something different.

[maiconpintoabreu]

Hi @raysan5 , is it ok to use #if defined to check for opengl 1.1 and swap rlSetTexture position?
Like:

#if defined(GRAPHICS_API_OPENGL_11)
    rlSetTexture(texture.id);
    rlBegin(RL_QUADS);
#else
    rlBegin(RL_QUADS);
    rlSetTexture(texture.id);
#endif

[maiconpintoabreu]

Running on Opengl 1.1, The opengl 1.1 rlSetTexture does not need to be after rlBegin as it does not include the code that I am trying to fix.

The Devs that will need to make sure that the rlSetTexture is after rlBegin is the ones doing draw of multiple Modes RL_TRIANGLES and RL_QUADS, if it is only RL_QUARDS, the rlSetTExture can be anywhere.

[maiconpintoabreu]

Changed the PR to draft as I am trying to test all the cases again

[maiconpintoabreu]

Hi @raysan5,

Tested and working:

GRAPHICS_API_OPENGL_33

• rlBegin -> rlSetTexture [Working]

GRAPHICS_API_OPENGL_11

• rlSetTexture -> rlBegin [Working]

GRAPHICS_API_OPENGL_21

• rlBegin -> rlSetTexture [Working]

GRAPHICS_API_OPENGL_43

• rlBegin -> rlSetTexture [Working]

GRAPHICS_API_OPENGL_ES2

• rlBegin -> rlSetTexture [Working]

rlBegin -> rlSetTexture only needed when using a mode like RL_TRIANGLES and change to another mode like RL_QUADS or RL_LINES.

[raysan5]

@maiconpintoabreu I'm afraid proposed solution is not ideal. raylib is intended to work the same way independently of the OpenGL version (despite feature limitations). And requesting different approaches depending on the version will confuse rlgl users. I prefer to keep the library with the current limitation.

[casperbear]

"raylib is intended to work the same way independently of the OpenGL version" This seems to be exactly the purpose of this PR. I'm no specialist but if OpenGL 3 behavior is purposefully different from OpenGL 1 (batches vs simple state machine) then rlgl, being a wrapper layer dealing with implementation details, is the perfect place to abstract this away.

[casperbear]

@raysan5 @maiconpintoabreu
rlSetTexture (OpenGL 3.3 implementation) sets
RLGL.currentBatch->draws[RLGL.currentBatch->drawCounter - 1].textureId = id;
and then rlBegin (OpenGL 3.3 implementation) sets
RLGL.currentBatch->draws[RLGL.currentBatch->drawCounter - 1].textureId = RLGL.State.defaultTextureId;
I've no idea what defaultTextureId is in this context, but here is a PR that dealt with seemingly similar issue
https://github.com/raysan5/raylib/pull/4364/files

[maiconpintoabreu]

Hi @casperbear, I am working on another PR to solve this issue without changing the order of settexture and begin.

#5200