solar_system/geometry.c

154 lines
5.2 KiB
C
Raw Normal View History

2020-12-19 16:56:01 +01:00
/*!\file geometry.h
2020-12-12 22:25:54 +01:00
*
* \brief quelques surfaces basiques sous forme polygonale : un plan
* (quad), un cube et une sphere.
*
* \author Farès BELHADJ, amsi@up8.edu
2020-12-19 16:56:01 +01:00
* \date December 2, 2020.
2020-12-12 22:25:54 +01:00
*/
#include "moteur.h"
#include <assert.h>
#if defined(_MSC_VER)
# define _USE_MATH_DEFINES
#endif
#include <math.h>
/*!\brief fabrique et renvoie une surface représentant un
* quadrilatère "debout" et à la profondeur 0. Il fait la hauteur et
* la largeur du cube unitaire (-1 à 1).*/
surface_t * mkQuad(void) {
const float
data[] = {
-1.0f, -1.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f,
1.0f, -1.0f, 0.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f,
-1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, -1.0f,
1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 1.0f, 1.0f, -1.0f
};
const int order[] = { 0, 1, 2, 2, 1, 3 };
surface_t * s;
/* on met du jaune partout */
2020-12-19 16:56:01 +01:00
const vec4 color0 = { 1.0f, 1.0f, 0.0f, 1.0f };
2020-12-12 22:25:54 +01:00
triangle_t t[2];
int i, j, o;
for(i = 0, o = 0; i < 2; ++i)
for(j = 0; j < 3; ++j, ++o) {
t[i].v[j].position = *(vec4 *)&(data[order[o] * 8]);
t[i].v[j].position.w = 1.0f;
t[i].v[j].normal = *(vec3 *)&(data[order[o] * 8 + 3]);
t[i].v[j].texCoord = *(vec2 *)&(data[order[o] * 8 + 6]);
t[i].v[j].color0 = color0;
}
s = newSurface(t, 2, 1, 1);
snormals(s);
return s;
}
/*!\brief fabrique et renvoie une surface représentant un
* cube unitaire (de -1 à 1).*/
surface_t * mkCube(void) {
const float
data[] = {
/* front */
-1.0f, -1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f,
1.0f, -1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f,
-1.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f,
1.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f,
/* back */
1.0f, -1.0f, -1.0f, 0.0f, 0.0f, -1.0f, 0.0f, 0.0f,
-1.0f, -1.0f, -1.0f, 0.0f, 0.0f, -1.0f, 1.0f, 0.0f,
1.0f, 1.0f, -1.0f, 0.0f, 0.0f, -1.0f, 0.0f, 1.0f,
-1.0f, 1.0f, -1.0f, 0.0f, 0.0f, -1.0f, 1.0f, 1.0f,
/* right */
1.0f, -1.0f, 1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f,
1.0f, -1.0f, -1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f,
1.0f, 1.0f, 1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 1.0f,
1.0f, 1.0f, -1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f,
/* left */
-1.0f, -1.0f, -1.0f, -1.0f, 0.0f, 0.0f, 0.0f, 0.0f,
-1.0f, -1.0f, 1.0f, -1.0f, 0.0f, 0.0f, 1.0f, 0.0f,
-1.0f, 1.0f, -1.0f, -1.0f, 0.0f, 0.0f, 0.0f, 1.0f,
-1.0f, 1.0f, 1.0f, -1.0f, 0.0f, 0.0f, 1.0f, 1.0f,
/* top */
-1.0f, 1.0f, 1.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f,
1.0f, 1.0f, 1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f,
-1.0f, 1.0f, -1.0f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f,
1.0f, 1.0f, -1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f,
/* bottom */
-1.0f, -1.0f, -1.0f, 0.0f, -1.0f, 0.0f, 0.0f, 0.0f,
1.0f, -1.0f, -1.0f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f,
-1.0f, -1.0f, 1.0f, 0.0f, -1.0f, 0.0f, 0.0f, 1.0f,
1.0f, -1.0f, 1.0f, 0.0f, -1.0f, 0.0f, 1.0f, 1.0f
};
const int order[] = { 0, 1, 2, 2, 1, 3 };
surface_t * s;
/* on met du vert-clair partout */
2020-12-19 16:56:01 +01:00
const vec4 color0 = { 0.5f, 1.0f, 0.0f, 1.0f };
2020-12-12 22:25:54 +01:00
triangle_t t[12];
int i, j, k, o;
for(i = 0, o = 0; i < 12; ++i)
for(j = 0; j < 3; ++j, ++o) {
k = 8 * (order[o % 6] + 4 * (i / 2));
t[i].v[j].position = *(vec4 *)&(data[k]);
t[i].v[j].position.w = 1.0f;
t[i].v[j].normal = *(vec3 *)&(data[k + 3]);
t[i].v[j].texCoord = *(vec2 *)&(data[k + 6]);
t[i].v[j].color0 = color0;
}
s = newSurface(t, 12, 1, 1);
snormals(s);
return s;
}
/*!\brief fabrique et renvoie une surface représentant une sphère
* centrée en zéro et de rayon 1. Elle est découpée en \a longitudes
* longitudes et \a latitudes latitudes. */
surface_t * mkSphere(int longitudes, int latitudes) {
2020-12-12 22:25:54 +01:00
triangle_t * t;
vertex_t * data;
double phi, theta, r, y;
double c2MPI_Long = 2.0 * M_PI / longitudes;
double cMPI_Lat = M_PI / latitudes;
/* on met du vert-clair partout */
2020-12-19 16:56:01 +01:00
const vec4 color0 = { 0.5f, 1.0f, 0.0f, 1.0f };
2020-12-12 22:25:54 +01:00
int z, nz, x, nx, zw, nzw, k, n = 2 * longitudes * latitudes;
assert(n);
data = malloc((longitudes + 1) * (latitudes + 1) * sizeof *data);
assert(data);
t = malloc(n * sizeof *t);
assert(t);
for(z = 0, k = 0; z <= latitudes; ++z) {
theta = -M_PI_2 + z * cMPI_Lat;
y = sin(theta);
r = cos(theta);
2020-12-12 22:25:54 +01:00
for(x = 0; x <= longitudes; ++x, ++k) {
phi = x * c2MPI_Long;
data[k].position.x = r * cos(phi);
data[k].position.y = y;
data[k].position.z = r * sin(phi);
data[k].position.w = 1.0f;
data[k].texCoord.x = phi / (2.0 * M_PI);
data[k].texCoord.y = (theta + M_PI_2) / M_PI;
data[k].color0 = color0;
data[k].normal = *(vec3 *)&(data[k].position);
}
}
for(z = 0, k = 0; z < latitudes; ++z) {
nz = z + 1;
zw = z * (longitudes + 1);
nzw = nz * (longitudes + 1);
for(x = 0; x < longitudes; ++x) {
nx = x + 1;
t[k].v[0] = data[zw + x];
t[k].v[1] = data[nzw + x];
t[k].v[2] = data[zw + nx];
tnormal(&t[k]);++k;
t[k].v[0] = data[zw + nx];
t[k].v[1] = data[nzw + x];
t[k].v[2] = data[nzw + nx];
tnormal(&t[k]);++k;
}
}
free(data);
return newSurface(t, n, 0, 1);
}