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#include <glm/glm.hpp>
#include "objects.hpp"
#include "graphics/Mesh.hpp"
#include "graphics/Vertex.hpp"
#define PI 3.1415926535
using namespace glm;
const int cube_num_v = 8;
Vertex cube_vertices[cube_num_v] = {
// first 4 - up edge
{ vec3(-1.0f, -1.0f, -1.0f), vec2(0.0f, 0.0f) },
{ vec3(1.0f, -1.0f, -1.0f), vec2(0.0f, 0.0f) },
{ vec3(1.0f, 1.0f, -1.0f), vec2(0.0f, 0.0f) },
{ vec3(-1.0f, 1.0f, -1.0f), vec2(0.0f, 0.0f) },
{ vec3(1.0f, 1.0f, 1.0f), vec2(0.0f, 0.0f) },
{ vec3(-1.0f, 1.0f, 1.0f), vec2(0.0f, 0.0f) },
{ vec3(-1.0f, -1.0f, 1.0f), vec2(0.0f, 0.0f) },
{ vec3(1.0f, -1.0f, 1.0f), vec2(0.0f, 0.0f) }
};
const int cube_num_i = 12 * 3;
GLuint cube_indices[cube_num_i] = {
0, 1, 2, // up edge
0, 2, 3,
2, 3, 4, // far edge
3, 4, 5,
0, 3, 5, // left edge
0, 5, 6,
0, 6, 7, // near edge
0, 1, 7,
1, 4, 7, // right edge
1, 2, 4,
4, 5, 6, // down edge
4, 6, 7
};
Mesh *form_cube()
{
return new Mesh(GL_TRIANGLES, cube_vertices, cube_num_v, cube_indices, cube_num_i);
}
Mesh *form_sphere(int longitude_count, int latitude_count)
{
/* The points on the sphere with radius r > 0 and center (x0, y0, z0)...
...can be parameterized via:
{
x = x0 + R * sin(tetta) * cos(phi)
y = y0 + R * sin(tetta) * sin(phi)
z = z0 + R * cos(tetta)
tetta : [0, PI]; phi : [0, 2PI]
}
or:
{
x = x0 + R * cos(phi) * cos(tetta)
y = y0 + R * cos(phi) * sin(tetta)
z = z0 + R * sin(phi)
}
our x0, y0, z0 = 0 */
int i, j, idx, k1, k2;
float x, y, z;
float s, t;
float radius = 1.0;
// sectors
float longitude_step = PI / longitude_count;
float longitude_angle;
// stacks
float latitude_step = 2 * PI / latitude_count;
float latitude_angle;
int sphere_num_v = (longitude_count + 1) * (latitude_count + 1);
Vertex *sphere_vertices = new Vertex[sphere_num_v];
for(i = 0, idx = 0; i <= longitude_count; i++) {
longitude_angle = i * longitude_step;
z = radius * cos(longitude_angle);
for(j = 0; j <= latitude_count; j++) {
latitude_angle = j * latitude_step;
x = radius * sinf(longitude_angle) * cosf(latitude_angle);
y = radius * sinf(longitude_angle) * sinf(latitude_angle);
sphere_vertices[idx].pos_coords = glm::vec3(x, y, z);
s = (float)j / longitude_count;
t = (float)i / latitude_count;
sphere_vertices[idx].tex_coords = glm::vec2(s, t);
idx++;
}
}
int sphere_num_i = (longitude_count - 1) * latitude_count * 6;
GLuint *sphere_indices = new GLuint[sphere_num_i];
for(i = 0, idx = 0; i < longitude_count; i++) {
k1 = i * (latitude_count+1);
k2 = k1 + (latitude_count+1);
for(j = 0; j < latitude_count; j++, k1++, k2++) {
if(i != 0)
{
sphere_indices[idx++] = k1;
sphere_indices[idx++] = k2;
sphere_indices[idx++] = k1 + 1;
}
if(i != (longitude_count-1))
{
sphere_indices[idx++] = k1 + 1;
sphere_indices[idx++] = k2;
sphere_indices[idx++] = k2 + 1;
}
}
}
Mesh *sphere = new Mesh(GL_TRIANGLES, sphere_vertices, sphere_num_v,
sphere_indices, sphere_num_i);
delete[] sphere_vertices;
delete[] sphere_indices;
return sphere;
}
Mesh *form_circle(int angle_count)
{
int i, idx, idy;
float x, y, z;
float radius = 1.0f;
float angle_step = 2 * PI / angle_count;
float angle;
Vertex *circle_vertices = new Vertex[angle_count];
GLuint *circle_indices = new GLuint[angle_count * 2];
for(i = 0, idx = 0, idy = 0; i < angle_count; i++) {
angle = i * angle_step;
x = radius * cosf(angle);
y = 0;
z = radius * sinf(angle);
circle_vertices[idx].pos_coords = glm::vec3(x, y, z);
circle_vertices[idx].tex_coords = glm::vec2(0, 0);
idx++;
if(i != 0) {
circle_indices[idy++] = i-1;
circle_indices[idy++] = i;
}
}
circle_indices[idy++] = i-1;
circle_indices[idy] = 0;
Mesh *circle = new Mesh(GL_LINES, circle_vertices, angle_count,
circle_indices, angle_count * 2);
delete[] circle_vertices;
delete[] circle_indices;
return circle;
}
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