Not sure why converting from color_t* to float is a problem

I am having problems initializing members of a struct
Here is the struct I am trying to initialize:

Code:

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typedef struct {
float Red;
float Green;
float Blue;
float Alpha;
} color_t;

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I am trying to pass an array of floats to a function using pointers

Here is a snippet of the function (I augmented other parameters and the rest of the code in the function)

Code:

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Light::Light(float * Colors) {
        Color->Red = Colors[Red];
        Color->Green = Colors[Green];
        Color->Blue = Colors[Blue];
        Color->Alpha = Colors[Alpha];
        Material = Materials;
}

---

And of course it is giving me the following errors:
[errors]
C:\Documents and Settings\Charles Thibault\Desktop\ourengine\LightImplementation.cpp (15) : error C2059: syntax error : 'constant'
C:\Documents and Settings\Charles Thibault\Desktop\ourengine\LightImplementation.cpp (16) : error C2039: 'Color' : is not a member of 'color_t'
c:\documents and settings\charles thibault\desktop\ourengine\light.h(13) : see declaration of 'color_t'
[/errors]
Oh and by the way I '#defined' Red, Green, Blue, and Alpha as 0, 1, 2, and 3, respectively (Yes, I seriously need to do that otherwise I forget what element of the array to use).

EDIT: I don't know if it is legal to have the member variable and the #defines the same words, i.e Red, Gree, Blue and Alpha are the same names for both the members of the struct and the macros

However, I tried taking them out and I am still getting the same errors

Why even declare the color_t structure if you're just going to pass an array of floats around? Pass a color_t structure.

well when I actually call the opengl function for setting up lights it can only accept a const float *

glLightfv(Number, GL_POSITION, (const float*)Location);

For some reason the lighting isn't getting done and i think it is because it cannot cast that to a const float*

Your code should work fine, except for:

Quote:

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Originally posted by Shadow12345

Oh and by the way I '#defined' Red, Green, Blue, and Alpha as 0, 1, 2, and 3, respectively

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Hehehe, there you have your problem.
You #define away the member variables' names! :D
Use constants instead, and you'll do fine.

This should be in the FAQ board as an argument of not using #define.


Clarification:

Code:

---

#define Red 1
struct C
{
  int Red;
};

//Will be converted by the preprocessor to:

struct C
{
  int 1;
};

//Which clearly is an error!

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