can i tell OPENGL to load texture from a memory address?
such as, i use windows function to load texture1.tga into memory, now memory 07000000-07010000 contains all data of texture1.tga .
can OPENGL read from this memory area and bind the texture to a polygon?
i just read about another way to load texture:
http://forum.gamedeception.net/archive/index.php?t-5425.html
which way is better?
You bet! That’s exactly what glTexImage2D does, where it takes a pointer in memory and loads it into the bound texture. The only caveat is you have to make sure whatever library you used laid out the image in a way OpenGL understands–no headers and such. If it’s laid out in memory with one pixel after another and the channels line up correctly, it’ll work fine.
can someone tell me what’s the correct program flow to bind texture to polygon? for example, i have successfully loaded all data of a TGA file into memory.
say address = 0x07000000-0x07010030
dword pMapFile contains the address 0x07000000
image format 128x128x32bit BGRA
the data in memory are like these:
x x x x x x x x x x x x x x x x x x 00 00 ff ff 00 ff 00 ff ff 00 00 ff … (header 18 bytes, color of each pixel follows)
i am following NEHE’s OGL tutorial:
http://nehe.gamedev.net/data/lessons/lesson.asp?lesson=06
http://nehe.gamedev.net/data/lessons/lesson.asp?lesson=24
but i am using ASM instead of C language, so i tried to convert the codes into ASM. but the outcome is wrong.
i don’t understand the purpose of:
glGenTexture(1,&texture[0].texID)
glBindTexture(GL_TEXTURE_2D,texture[0].texID)
glTexImage2D(… , texture[0].imagedata)
what are " &texture[0].texID" “texture[0].texID” “texture[0].imagedata”
are they memory addresses? or just ID numbers?
how do they relate to the memory address 0x07000000 ?
in my program, the polygon only shows red/black strips , while the TGA contains red/green/blue colors.