#include <cylinder.h>
#include <stdio.h>


void VertexBuf::push(GLfloat x, GLfloat y, GLfloat z, Color &c)
{
	vertices[i] = x;
	vertices[i+1] = y;
	vertices[i+2] = z;
	colors[i] = c.r;
	colors[i+1] = c.g;
	colors[i+2] = c.b;
	i += 3;
}


void Cylinder::build_face(float z)
{
	Color color(c);
	for (unsigned j = 0; j < nb_fac; j++) {
		vb.push(0, 0, z, color);
		vb.push(cos(angle*j) * r, sin(angle*j) * r, z, color);
		vb.push(cos(angle*(j+1)) * r, sin(angle*(j+1)) * r, z, color);
		if (j % (nb_fac/4) == 0) {
			if (j % (nb_fac/2) == 0) {
				color.r *= .8;
				color.g *= .8;
				color.b *= .8;
			}
			else {
				color = c;
			}
		}
	}
}


void Cylinder::build_faces()
{
	build_face(-ep/2);
	build_face(ep/2);
}


void Cylinder::build_side()
{
	Color color(c.r*.7, c.g*.7, c.b*.7);
	for (unsigned i = 0; i < nb_fac+1; i++) {
		vb.push(cos(angle*i) * r, sin(angle*i) * r, -ep/2, color);
		vb.push(cos(angle*i) * r, sin(angle*i) * r, ep/2, color);
	}
}


void Cylinder::draw(QOpenGLFunctions &f, int pos, int col)
{
	f.glVertexAttribPointer(pos, 3, GL_FLOAT, GL_FALSE, 0, vb.vertices);
	f.glVertexAttribPointer(col, 3, GL_FLOAT, GL_FALSE, 0, vb.colors);
	f.glEnableVertexAttribArray(pos);
	f.glEnableVertexAttribArray(col);
	f.glDrawArrays(GL_TRIANGLES, 0, face_size);
	f.glDrawArrays(GL_TRIANGLES, face_size, face_size);
	f.glDrawArrays(GL_QUAD_STRIP,
				   face_size * 2,
				   side_size);
	f.glDisableVertexAttribArray(pos);
	f.glDisableVertexAttribArray(col);
}