[1.8] Question about OpenGL/ GuiRendering

[Failender]

I want to create a lot of guis to follow a specific structure, so I thought I should work with modular rendering.

No problem with most of it, just one question.

GuiButtons and GuiLabels have the two lines

GlStateManager.tryBlendFuncSeparate(770, 771, 1, 0);
        GlStateManager.blendFunc(770, 771);

what are they doing?

[TheGreyGhost]

Hi

 

it's related to alpha blending (transparencies).

To figure it out:

1) GLstateManager.blendFunc shows

GL11.glBlendFunc

 

and a quick search in GL11 for the hexadecimal format of 770 and 771 (0x302 and 0x303) gives

GL_SRC_ALPHA and GL_ONE_MINUS_SRC_ALPHA

 

i.e. GL11.glBlendFunc(GR_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

more info in this chapter

http://www.glprogramming.com/red/chapter06.html

 

-TGG