[1.14.4] render Texture in full white but keep alpha

Hi there,

I'm trying to render my custom entity's blockstate member with my own texture all over it but keeping the original alpha channel. If that's too hard I'll settle for rendering it in all white.

I'm really new to GL11 and the closest I've gotten is this:

GlStateManager.disableTexture(); //disables alpha as well
GlStateManager.disableLighting();
GlStateManager.color4f(1.0F, 1.0F, 1.0F, 1.0F);
blockrendererdispatcher.renderBlockBrightness(Blocks.TNT.getDefaultState(), 1.0F);

But that completely disables the texture, including the alpha channel.

If anyone could link any good resources to learn GL's basic function that would also be greatly appreciated.