我正在尝试制作一个颜色色板工具,在其中给它提供n种颜色,并用这些颜色在中间合并一个n边形。
到目前为止,它只制作了一个n-gon(不指定颜色,它会随机生成它们)。
但是颜色不是在中心融合而是一个顶点。
对此有任何解决办法吗?
#include <GLFW/glfw3.h>
#include <iostream>
#include <cmath>
float randfloat(){
float r = ((float)(rand() % 10))/10;
return r;
}
int main() {
int side_count;
std::cout<<"Type the no. of sides: "<<std::endl;
std::cin>>side_count;
srand(time(NULL));
std::cout<<randfloat()<<std::endl;
std::cout<<randfloat()<<std::endl;
float rs[side_count];
float gs[side_count];
float bs[side_count];
for (int i=0;i<side_count;i++)
{
rs[i] = randfloat();
gs[i] = randfloat();
bs[i] = randfloat();
}
GLFWwindow* window;
if (!glfwInit())
return 1;
window = glfwCreateWindow(800, 800, "Window", NULL, NULL);
if (!window) {
glfwTerminate();
return 1;
}
glfwMakeContextCurrent(window);
if(glewInit()!=GLEW_OK)
std::cout<<"Error"<<std::endl;
while(!glfwWindowShouldClose(window)) {
glClear(GL_COLOR_BUFFER_BIT);
glClearColor(0.11f,0.15f,0.17f,1.0f);
glBegin(GL_POLYGON);
//glColor3f(1.0f,0.0f,0.0f);glVertex3f(-0.5f,0.0f,0.0f);
for(int i=0; i<side_count;i++)
{
float r = rs[i];
float g = gs[i];
float b = bs[i];
float x = 0.5f * sin(2.0*M_PI*i/side_count);
float y = 0.5f * cos(2.0*M_PI*i/side_count);
glColor3f(r,g,b);glVertex2f(x,y);
}
glEnd();
glfwSwapBuffers(window);
glfwPollEvents();
}
glfwTerminate();
return 0;
}
答案 0 :(得分:2)
您要做的就是在圆形的中心向GL_POLYGON
原语添加一个新点:
glBegin(GL_TRIANGLE_FAN);
glColor3f(0.5f, 0.5f, 0.5f);
glVertex2f(0, 0);
for(int i=0; i <= side_count; i++)
{
float r = rs[i % side_count];
float g = gs[i % side_count];
float b = bs[i % side_count];
float x = 0.5f * sin(2.0*M_PI*i/side_count);
float y = 0.5f * cos(2.0*M_PI*i/side_count);
glColor3f(r, g, b);
glVertex2f(x, y);
}
glEnd();
请注意,您必须定义中心点的颜色。在代码段中,我选择了(0.5,0.5,0.5)。
也可以使用GL_TRIANGLE_FAN
代替GL_POLYGON
。