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There is really no use for immediate mode anymore; I'm of the opinion that if you lament the loss of immediate mode, you simply don't want to learn the newer, m

There is really no use for immediate mode anymore; I'm of the opinion that if you lament the loss of immediate mode, you simply don't want to learn the newer, more efficient ways of doing the same thing. Ask yourself this, if immediate mode never existed, would you still say that the ES2.0 method is still "basically impossible to learn"? I assure you that it is very possible to learn.

jra101 14y ago
Immediate mode is very useful for drawing a single triangle that fully covers the viewport, something that is quite common for any sort of image processing or post processing. In these cases your performance will entirely be limited by the complexity of your fragment shader or by raw fill rate and not by the method you used to submit the vertices to the GPU.
- kcbanner 14y ago
  Agreed, and I would also add that the overhead in terms of development time to set up the boilerplate to render this triangle via immediate mode and the newer methods would be comparable.
ajross 14y ago
Terminology quibble: you don't mean "immediate mode" in the sense it's been used in the community. OpenGL is still an immediate mode API under all circumstances. There is no scene graph. I probably should have said "streamed vertex" or "begin/end" to make things clearer. Did you learn ES2 (i.e. create a buffer object, fill it, pass in attribute pointers, goof up the stride values, do it again, draw)? Or did your first triangle come out via begin/vertex/vertex/vertex/end?
- kcbanner 14y ago
  My first triangle came out when there was no programmable pipeline, so yep, via immediate mode (any by that I mean begin/end). Then, when OpenGL 2.0 came out, I learned how to use buffers to do it instead. Are you saying that immediate mode should be used in all cases, even for rendering a complex mesh where you will need to spend CPU cycles iterating and uploading vertices to the CPU every frame?
  - ajross 14y ago
    Goodness no. I think you missed the last paragraph I wrote in the note you responded to. I'm saying that the begin/end APIs should not have been dropped from the spec in ES2. There needs to be some kind of equivalent, because high performances games and driver writers aren't the only users of the API.
    - rrmm 14y ago
      It seems like the API could probably be replicated in glu or glut, so people who just want the fixed pipeline could get it easily.
      - ajross 14y ago
        Sure, it could be. But the problem was it wasn't, so ES2 came out and effectively abandoned huge chunks of existing code the relied on the fixed function pipeline. And they had no answer for what people were supposed to replace it with. Thus the aggrieved flaming from people like jwz who just want to port some software.

jra101 14y ago

Immediate mode is very useful for drawing a single triangle that fully covers the viewport, something that is quite common for any sort of image processing or post processing. In these cases your performance will entirely be limited by the complexity of your fragment shader or by raw fill rate and not by the method you used to submit the vertices to the GPU.

kcbanner 14y ago
Agreed, and I would also add that the overhead in terms of development time to set up the boilerplate to render this triangle via immediate mode and the newer methods would be comparable.

ajross 14y ago

Terminology quibble: you don't mean "immediate mode" in the sense it's been used in the community. OpenGL is still an immediate mode API under all circumstances. There is no scene graph. I probably should have said "streamed vertex" or "begin/end" to make things clearer. Did you learn ES2 (i.e. create a buffer object, fill it, pass in attribute pointers, goof up the stride values, do it again, draw)? Or did your first triangle come out via begin/vertex/vertex/vertex/end?

kcbanner 14y ago
My first triangle came out when there was no programmable pipeline, so yep, via immediate mode (any by that I mean begin/end). Then, when OpenGL 2.0 came out, I learned how to use buffers to do it instead. Are you saying that immediate mode should be used in all cases, even for rendering a complex mesh where you will need to spend CPU cycles iterating and uploading vertices to the CPU every frame?
- ajross 14y ago
  Goodness no. I think you missed the last paragraph I wrote in the note you responded to. I'm saying that the begin/end APIs should not have been dropped from the spec in ES2. There needs to be some kind of equivalent, because high performances games and driver writers aren't the only users of the API.
  - rrmm 14y ago
    It seems like the API could probably be replicated in glu or glut, so people who just want the fixed pipeline could get it easily.
    - ajross 14y ago
      Sure, it could be. But the problem was it wasn't, so ES2 came out and effectively abandoned huge chunks of existing code the relied on the fixed function pipeline. And they had no answer for what people were supposed to replace it with. Thus the aggrieved flaming from people like jwz who just want to port some software.