Select a color using the number in openGL -

you know glcolor3f(), contains red green , blue values. i'm developing simple program should allow select color i'm not sure how set set of rgb color values make callback. example,

int red = (1,0,0); glcolor3f(red); 

obviously, has error i've tried other ways make work int[] red = {1,0,0}; still didn't work. can give me suggestions?

update #1: made program test. first code line should global state.

glfloat color[3] = {1,0,0}; 

then color should changed rand() in following:

int r1 = rand() % 100; if(r1 < 50)     color = {0,1,0}; else     color = {0,0,1};  glcolor3fv(color); 

first: learn proper syntax of c, because this

int red = (1,0,0); 

is not valid c. (c not know tuple type). types matter.

well use glfloat array , pass glcolor3fv (if want use integers must use glcolor3i[v].

glfloat const red[3] = {1,0,0}; glcolor3fv(red); 

but that's not useful, because not want artificially limit user's choices. present them color selection widget, returns individual color values, in struct , pass opengl

struct color {     enum {color_srgb, color_hsv, color_lab, /* other color spaces */} type;     union {         struct { glfloat r,g,b};         struct { glfloat h,s,v};         struct { glfloat l,a,b};         /* other color spaces */     }; };  /* defined somewhere else, converts color rgb color space */ void to_rgb(glfloat rgb[3], color const *c);  void setcolor(color const *c)  {     glfloat rgb[3];     to_rgb(rgb, c);     glcolor3fv(rgb); } 

update due comment

to randomly select set of colors use this:

glfloat const green[] = {0.f, 1.f, 0.f}; glfloat const blue[]  = {0.f, 0.f, 1.f}; 

in c arrays have interesting property, r-value pointer first element. hence practical means, wherever array goes argument, can use pointer.

glfloat const *color; /* pointer, not array */ int r1 = rand() % 100; if(r1 < 50)     color = green; else     color = blue;  glcolor3fv(color);