i am no pro and my english is bad, too
, but i will try to explain:
Shader-code is a code which for example changes the value of each pixel on a model.
all pixel have got like 4 main values: red, green, blue and alpha.
with pixel-shaders you can change these values:
ps.1.3
def c0,0.1,0.2,0.3,1 // a register called c0 with the red value 0.1 , the grenn value 0.2 ...
tex t0 // gets the first texture of a model
tex t1 // gets the second
mul r0,t0,t1 // multiplys the first texture with the second and stores this in a kind of register
add r0,r0,c0 // adds to the mixture the rgba-values of c0
mov t0,r0 // puts the new information back on the first texture and on the model
i dont know if this would work but this kind of logic helped me to understand the topic a little bit...
