I have just started to study about textures. I found that OpenGL provides new techniques for textures using texture objects which were not used previously. In Red Book, in chapter on textures, they say, many of the techniques described there are not in use today. So basically, I want to know from where I can start learning about the MODERN techniques used for textures without struggling with previous techniques? And also tell me if it is useful to learn previous techniques as it said we can appreciate new techniques if we know the old techniques.
Which old techniques exactly ? I believe it was about old multitexturing, texture combine, etc ?
I personally find that learning about deprecated stuff is interesting ‘just for the sake of it’ but do not spend on lot time on it, just browse it.
Modern way is do that in a shader, which gives a lot more flexibility.
For example you can use data from a texture to access data from another texture, using both as 2D arrays of generic data rather than the old concept of projecting an image into a geometry.
What I knew till now about textures was using texture objects. I loaded image data in an array and then stored that in a texture object and when drawing a quad, I simply mapped 4 vertices of textures to 4 vertices of quad. Now the problem was than, when I use many textures, say 15, the application started slowing down, may be because it was too costly for it to store such a large information at run time. So I need to know how to optimize that?