1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/meshgen.cc	Mon Jun 22 05:05:37 2015 +0300
     1.3 @@ -0,0 +1,487 @@
     1.4 +#include <stdio.h>
     1.5 +#include "meshgen.h"
     1.6 +#include "mesh.h"
     1.7 +
     1.8 +// -------- sphere --------
     1.9 +
    1.10 +#define SURAD(u)	((u) * 2.0 * M_PI)
    1.11 +#define SVRAD(v)	((v) * M_PI)
    1.12 +
    1.13 +static Vector3 sphvec(float theta, float phi)
    1.14 +{
    1.15 +	return Vector3(sin(theta) * sin(phi),
    1.16 +			cos(phi),
    1.17 +			cos(theta) * sin(phi));
    1.18 +}
    1.19 +
    1.20 +void gen_sphere(Mesh *mesh, float rad, int usub, int vsub, float urange, float vrange)
    1.21 +{
    1.22 +	if(usub < 4) usub = 4;
    1.23 +	if(vsub < 2) vsub = 2;
    1.24 +
    1.25 +	int uverts = usub + 1;
    1.26 +	int vverts = vsub + 1;
    1.27 +
    1.28 +	int num_verts = uverts * vverts;
    1.29 +	int num_quads = usub * vsub;
    1.30 +	int num_tri = num_quads * 2;
    1.31 +
    1.32 +	mesh->clear();
    1.33 +	Vector3 *varr = (Vector3*)mesh->set_attrib_data(MESH_ATTR_VERTEX, 3, num_verts, 0);
    1.34 +	Vector3 *narr = (Vector3*)mesh->set_attrib_data(MESH_ATTR_NORMAL, 3, num_verts, 0);
    1.35 +	Vector3 *tarr = (Vector3*)mesh->set_attrib_data(MESH_ATTR_TANGENT, 3, num_verts, 0);
    1.36 +	Vector2 *uvarr = (Vector2*)mesh->set_attrib_data(MESH_ATTR_TEXCOORD, 2, num_verts, 0);
    1.37 +	unsigned int *idxarr = mesh->set_index_data(num_tri * 3, 0);
    1.38 +
    1.39 +	float du = urange / (float)(uverts - 1);
    1.40 +	float dv = vrange / (float)(vverts - 1);
    1.41 +
    1.42 +	float u = 0.0;
    1.43 +	for(int i=0; i<uverts; i++) {
    1.44 +		float theta = SURAD(u * urange);
    1.45 +
    1.46 +		float v = 0.0;
    1.47 +		for(int j=0; j<vverts; j++) {
    1.48 +			float phi = SVRAD(v * vrange);
    1.49 +
    1.50 +			Vector3 pos = sphvec(theta, phi);
    1.51 +
    1.52 +			*varr++ = pos * rad;
    1.53 +			*narr++ = pos;
    1.54 +			*tarr++ = (sphvec(theta + 0.1f, (float)M_PI / 2.0f) - sphvec(theta - 0.1f, (float)M_PI / 2.0f)).normalized();
    1.55 +			*uvarr++ = Vector2(u * urange, v * vrange);
    1.56 +
    1.57 +			if(i < usub && j < vsub) {
    1.58 +				int idx = i * vverts + j;
    1.59 +				*idxarr++ = idx;
    1.60 +				*idxarr++ = idx + 1;
    1.61 +				*idxarr++ = idx + vverts + 1;
    1.62 +
    1.63 +				*idxarr++ = idx;
    1.64 +				*idxarr++ = idx + vverts + 1;
    1.65 +				*idxarr++ = idx + vverts;
    1.66 +			}
    1.67 +
    1.68 +			v += dv;
    1.69 +		}
    1.70 +		u += du;
    1.71 +	}
    1.72 +}
    1.73 +
    1.74 +
    1.75 +// -------- cylinder --------
    1.76 +
    1.77 +static Vector3 cylvec(float theta, float height)
    1.78 +{
    1.79 +	return Vector3(sin(theta), height, cos(theta));
    1.80 +}
    1.81 +
    1.82 +void gen_cylinder(Mesh *mesh, float rad, float height, int usub, int vsub, int capsub, float urange, float vrange)
    1.83 +{
    1.84 +	if(usub < 4) usub = 4;
    1.85 +	if(vsub < 1) vsub = 1;
    1.86 +
    1.87 +	int uverts = usub + 1;
    1.88 +	int vverts = vsub + 1;
    1.89 +
    1.90 +	int num_body_verts = uverts * vverts;
    1.91 +	int num_body_quads = usub * vsub;
    1.92 +	int num_body_tri = num_body_quads * 2;
    1.93 +
    1.94 +	int capvverts = capsub ? capsub + 1 : 0;
    1.95 +	int num_cap_verts = uverts * capvverts;
    1.96 +	int num_cap_quads = usub * capsub;
    1.97 +	int num_cap_tri = num_cap_quads * 2;
    1.98 +
    1.99 +	int num_verts = num_body_verts + num_cap_verts * 2;
   1.100 +	int num_tri = num_body_tri + num_cap_tri * 2;
   1.101 +
   1.102 +	mesh->clear();
   1.103 +	Vector3 *varr = (Vector3*)mesh->set_attrib_data(MESH_ATTR_VERTEX, 3, num_verts, 0);
   1.104 +	Vector3 *narr = (Vector3*)mesh->set_attrib_data(MESH_ATTR_NORMAL, 3, num_verts, 0);
   1.105 +	Vector3 *tarr = (Vector3*)mesh->set_attrib_data(MESH_ATTR_TANGENT, 3, num_verts, 0);
   1.106 +	Vector2 *uvarr = (Vector2*)mesh->set_attrib_data(MESH_ATTR_TEXCOORD, 2, num_verts, 0);
   1.107 +	unsigned int *idxarr = mesh->set_index_data(num_tri * 3, 0);
   1.108 +
   1.109 +	float du = urange / (float)(uverts - 1);
   1.110 +	float dv = vrange / (float)(vverts - 1);
   1.111 +
   1.112 +	float u = 0.0;
   1.113 +	for(int i=0; i<uverts; i++) {
   1.114 +		float theta = SURAD(u);
   1.115 +
   1.116 +		float v = 0.0;
   1.117 +		for(int j=0; j<vverts; j++) {
   1.118 +			float y = (v - 0.5) * height;
   1.119 +			Vector3 pos = cylvec(theta, y);
   1.120 +
   1.121 +			*varr++ = Vector3(pos.x * rad, pos.y, pos.z * rad);
   1.122 +			*narr++ = Vector3(pos.x, 0.0, pos.z);
   1.123 +			*tarr++ = (cylvec(theta + 0.1, 0.0) - cylvec(theta - 0.1, 0.0)).normalized();
   1.124 +			*uvarr++ = Vector2(u * urange, v * vrange);
   1.125 +
   1.126 +			if(i < usub && j < vsub) {
   1.127 +				int idx = i * vverts + j;
   1.128 +
   1.129 +				*idxarr++ = idx;
   1.130 +				*idxarr++ = idx + vverts + 1;
   1.131 +				*idxarr++ = idx + 1;
   1.132 +
   1.133 +				*idxarr++ = idx;
   1.134 +				*idxarr++ = idx + vverts;
   1.135 +				*idxarr++ = idx + vverts + 1;
   1.136 +			}
   1.137 +
   1.138 +			v += dv;
   1.139 +		}
   1.140 +		u += du;
   1.141 +	}
   1.142 +
   1.143 +
   1.144 +	// now the cap!
   1.145 +	if(!capsub) {
   1.146 +		return;
   1.147 +	}
   1.148 +
   1.149 +	dv = 1.0 / (float)(capvverts - 1);
   1.150 +
   1.151 +	u = 0.0;
   1.152 +	for(int i=0; i<uverts; i++) {
   1.153 +		float theta = SURAD(u);
   1.154 +
   1.155 +		float v = 0.0;
   1.156 +		for(int j=0; j<capvverts; j++) {
   1.157 +			float r = v * rad;
   1.158 +
   1.159 +			Vector3 pos = cylvec(theta, height / 2.0) * r;
   1.160 +			pos.y = height / 2.0;
   1.161 +			Vector3 tang = (cylvec(theta + 0.1, 0.0) - cylvec(theta - 0.1, 0.0)).normalized();
   1.162 +
   1.163 +			*varr++ = pos;
   1.164 +			*narr++ = Vector3(0, 1, 0);
   1.165 +			*tarr++ = tang;
   1.166 +			*uvarr++ = Vector2(u * urange, v);
   1.167 +
   1.168 +			pos.y = -height / 2.0;
   1.169 +			*varr++ = pos;
   1.170 +			*narr++ = Vector3(0, -1, 0);
   1.171 +			*tarr++ = -tang;
   1.172 +			*uvarr++ = Vector2(u * urange, v);
   1.173 +
   1.174 +			if(i < usub && j < capsub) {
   1.175 +				unsigned int idx = num_body_verts + (i * capvverts + j) * 2;
   1.176 +
   1.177 +				unsigned int vidx[4] = {
   1.178 +					idx,
   1.179 +					idx + capvverts * 2,
   1.180 +					idx + (capvverts + 1) * 2,
   1.181 +					idx + 2
   1.182 +				};
   1.183 +
   1.184 +				*idxarr++ = vidx[0];
   1.185 +				*idxarr++ = vidx[2];
   1.186 +				*idxarr++ = vidx[1];
   1.187 +				*idxarr++ = vidx[0];
   1.188 +				*idxarr++ = vidx[3];
   1.189 +				*idxarr++ = vidx[2];
   1.190 +
   1.191 +				*idxarr++ = vidx[0] + 1;
   1.192 +				*idxarr++ = vidx[1] + 1;
   1.193 +				*idxarr++ = vidx[2] + 1;
   1.194 +				*idxarr++ = vidx[0] + 1;
   1.195 +				*idxarr++ = vidx[2] + 1;
   1.196 +				*idxarr++ = vidx[3] + 1;
   1.197 +			}
   1.198 +
   1.199 +			v += dv;
   1.200 +		}
   1.201 +		u += du;
   1.202 +	}
   1.203 +}
   1.204 +
   1.205 +// -------- cone --------
   1.206 +
   1.207 +static Vector3 conevec(float theta, float y, float height)
   1.208 +{
   1.209 +	float scale = 1.0 - y / height;
   1.210 +	return Vector3(sin(theta) * scale, y, cos(theta) * scale);
   1.211 +}
   1.212 +
   1.213 +void gen_cone(Mesh *mesh, float rad, float height, int usub, int vsub, int capsub, float urange, float vrange)
   1.214 +{
   1.215 +	if(usub < 4) usub = 4;
   1.216 +	if(vsub < 1) vsub = 1;
   1.217 +
   1.218 +	int uverts = usub + 1;
   1.219 +	int vverts = vsub + 1;
   1.220 +
   1.221 +	int num_body_verts = uverts * vverts;
   1.222 +	int num_body_quads = usub * vsub;
   1.223 +	int num_body_tri = num_body_quads * 2;
   1.224 +
   1.225 +	int capvverts = capsub ? capsub + 1 : 0;
   1.226 +	int num_cap_verts = uverts * capvverts;
   1.227 +	int num_cap_quads = usub * capsub;
   1.228 +	int num_cap_tri = num_cap_quads * 2;
   1.229 +
   1.230 +	int num_verts = num_body_verts + num_cap_verts;
   1.231 +	int num_tri = num_body_tri + num_cap_tri;
   1.232 +
   1.233 +	mesh->clear();
   1.234 +	Vector3 *varr = (Vector3*)mesh->set_attrib_data(MESH_ATTR_VERTEX, 3, num_verts, 0);
   1.235 +	Vector3 *narr = (Vector3*)mesh->set_attrib_data(MESH_ATTR_NORMAL, 3, num_verts, 0);
   1.236 +	Vector3 *tarr = (Vector3*)mesh->set_attrib_data(MESH_ATTR_TANGENT, 3, num_verts, 0);
   1.237 +	Vector2 *uvarr = (Vector2*)mesh->set_attrib_data(MESH_ATTR_TEXCOORD, 2, num_verts, 0);
   1.238 +	unsigned int *idxarr = mesh->set_index_data(num_tri * 3, 0);
   1.239 +
   1.240 +	float du = urange / (float)(uverts - 1);
   1.241 +	float dv = vrange / (float)(vverts - 1);
   1.242 +
   1.243 +	float u = 0.0;
   1.244 +	for(int i=0; i<uverts; i++) {
   1.245 +		float theta = SURAD(u);
   1.246 +
   1.247 +		float v = 0.0;
   1.248 +		for(int j=0; j<vverts; j++) {
   1.249 +			float y = v * height;
   1.250 +			Vector3 pos = conevec(theta, y, height);
   1.251 +
   1.252 +			Vector3 tang = (conevec(theta + 0.1, 0.0, height) - conevec(theta - 0.1, 0.0, height)).normalized();
   1.253 +			Vector3 bitang = (conevec(theta, y + 0.1, height) - pos).normalized();
   1.254 +
   1.255 +			*varr++ = Vector3(pos.x * rad, pos.y, pos.z * rad);
   1.256 +			*narr++ = cross_product(tang, bitang);
   1.257 +			*tarr++ = tang;
   1.258 +			*uvarr++ = Vector2(u * urange, v * vrange);
   1.259 +
   1.260 +			if(i < usub && j < vsub) {
   1.261 +				int idx = i * vverts + j;
   1.262 +
   1.263 +				*idxarr++ = idx;
   1.264 +				*idxarr++ = idx + vverts + 1;
   1.265 +				*idxarr++ = idx + 1;
   1.266 +
   1.267 +				*idxarr++ = idx;
   1.268 +				*idxarr++ = idx + vverts;
   1.269 +				*idxarr++ = idx + vverts + 1;
   1.270 +			}
   1.271 +
   1.272 +			v += dv;
   1.273 +		}
   1.274 +		u += du;
   1.275 +	}
   1.276 +
   1.277 +
   1.278 +	// now the bottom cap!
   1.279 +	if(!capsub) {
   1.280 +		return;
   1.281 +	}
   1.282 +
   1.283 +	dv = 1.0 / (float)(capvverts - 1);
   1.284 +
   1.285 +	u = 0.0;
   1.286 +	for(int i=0; i<uverts; i++) {
   1.287 +		float theta = SURAD(u);
   1.288 +
   1.289 +		float v = 0.0;
   1.290 +		for(int j=0; j<capvverts; j++) {
   1.291 +			float r = v * rad;
   1.292 +
   1.293 +			Vector3 pos = conevec(theta, 0.0, height) * r;
   1.294 +			Vector3 tang = (cylvec(theta + 0.1, 0.0) - cylvec(theta - 0.1, 0.0)).normalized();
   1.295 +
   1.296 +			*varr++ = pos;
   1.297 +			*narr++ = Vector3(0, -1, 0);
   1.298 +			*tarr++ = tang;
   1.299 +			*uvarr++ = Vector2(u * urange, v);
   1.300 +
   1.301 +			if(i < usub && j < capsub) {
   1.302 +				unsigned int idx = num_body_verts + i * capvverts + j;
   1.303 +
   1.304 +				unsigned int vidx[4] = {
   1.305 +					idx,
   1.306 +					idx + capvverts,
   1.307 +					idx + (capvverts + 1),
   1.308 +					idx + 1
   1.309 +				};
   1.310 +
   1.311 +				*idxarr++ = vidx[0];
   1.312 +				*idxarr++ = vidx[1];
   1.313 +				*idxarr++ = vidx[2];
   1.314 +				*idxarr++ = vidx[0];
   1.315 +				*idxarr++ = vidx[2];
   1.316 +				*idxarr++ = vidx[3];
   1.317 +			}
   1.318 +
   1.319 +			v += dv;
   1.320 +		}
   1.321 +		u += du;
   1.322 +	}
   1.323 +}
   1.324 +
   1.325 +
   1.326 +// -------- plane --------
   1.327 +
   1.328 +void gen_plane(Mesh *mesh, float width, float height, int usub, int vsub)
   1.329 +{
   1.330 +	gen_heightmap(mesh, width, height, usub, vsub, 0);
   1.331 +}
   1.332 +
   1.333 +
   1.334 +// ----- heightmap ------
   1.335 +
   1.336 +void gen_heightmap(Mesh *mesh, float width, float height, int usub, int vsub, float (*hf)(float, float, void*), void *hfdata)
   1.337 +{
   1.338 +	if(usub < 1) usub = 1;
   1.339 +	if(vsub < 1) vsub = 1;
   1.340 +
   1.341 +	mesh->clear();
   1.342 +
   1.343 +	int uverts = usub + 1;
   1.344 +	int vverts = vsub + 1;
   1.345 +	int num_verts = uverts * vverts;
   1.346 +
   1.347 +	int num_quads = usub * vsub;
   1.348 +	int num_tri = num_quads * 2;
   1.349 +
   1.350 +	Vector3 *varr = (Vector3*)mesh->set_attrib_data(MESH_ATTR_VERTEX, 3, num_verts, 0);
   1.351 +	Vector3 *narr = (Vector3*)mesh->set_attrib_data(MESH_ATTR_NORMAL, 3, num_verts, 0);
   1.352 +	Vector3 *tarr = (Vector3*)mesh->set_attrib_data(MESH_ATTR_TANGENT, 3, num_verts, 0);
   1.353 +	Vector2 *uvarr = (Vector2*)mesh->set_attrib_data(MESH_ATTR_TEXCOORD, 2, num_verts, 0);
   1.354 +	unsigned int *idxarr = mesh->set_index_data(num_tri * 3, 0);
   1.355 +
   1.356 +	float du = 1.0 / (float)usub;
   1.357 +	float dv = 1.0 / (float)vsub;
   1.358 +
   1.359 +	float u = 0.0;
   1.360 +	for(int i=0; i<uverts; i++) {
   1.361 +		float v = 0.0;
   1.362 +		for(int j=0; j<vverts; j++) {
   1.363 +			float x = (u - 0.5) * width;
   1.364 +			float y = (v - 0.5) * height;
   1.365 +			float z = hf ? hf(u, v, hfdata) : 0.0;
   1.366 +
   1.367 +			Vector3 normal = Vector3(0, 0, 1);
   1.368 +			if(hf) {
   1.369 +				float u1z = hf(u + du, v, hfdata);
   1.370 +				float v1z = hf(u, v + dv, hfdata);
   1.371 +
   1.372 +				Vector3 tang = Vector3(du * width, 0, u1z - z);
   1.373 +				Vector3 bitan = Vector3(0, dv * height, v1z - z);
   1.374 +				normal = cross_product(tang, bitan).normalized();
   1.375 +			}
   1.376 +
   1.377 +			*varr++ = Vector3(x, y, z);
   1.378 +			*narr++ = normal;
   1.379 +			*tarr++ = Vector3(1, 0, 0);
   1.380 +			*uvarr++ = Vector2(u, v);
   1.381 +
   1.382 +			if(i < usub && j < vsub) {
   1.383 +				int idx = i * vverts + j;
   1.384 +
   1.385 +				*idxarr++ = idx;
   1.386 +				*idxarr++ = idx + vverts + 1;
   1.387 +				*idxarr++ = idx + 1;
   1.388 +
   1.389 +				*idxarr++ = idx;
   1.390 +				*idxarr++ = idx + vverts;
   1.391 +				*idxarr++ = idx + vverts + 1;
   1.392 +			}
   1.393 +
   1.394 +			v += dv;
   1.395 +		}
   1.396 +		u += du;
   1.397 +	}
   1.398 +}
   1.399 +
   1.400 +// ----- heightmap ------
   1.401 +
   1.402 +void gen_box(Mesh *mesh, float xsz, float ysz, float zsz)
   1.403 +{
   1.404 +	mesh->clear();
   1.405 +
   1.406 +	const int num_faces = 6;
   1.407 +	int num_verts = num_faces * 4;
   1.408 +	int num_tri = num_faces * 2;
   1.409 +
   1.410 +	float x = xsz / 2.0;
   1.411 +	float y = ysz / 2.0;
   1.412 +	float z = zsz / 2.0;
   1.413 +
   1.414 +	Vector3 *varr = (Vector3*)mesh->set_attrib_data(MESH_ATTR_VERTEX, 3, num_verts, 0);
   1.415 +	Vector3 *narr = (Vector3*)mesh->set_attrib_data(MESH_ATTR_NORMAL, 3, num_verts, 0);
   1.416 +	Vector3 *tarr = (Vector3*)mesh->set_attrib_data(MESH_ATTR_TANGENT, 3, num_verts, 0);
   1.417 +	Vector2 *uvarr = (Vector2*)mesh->set_attrib_data(MESH_ATTR_TEXCOORD, 2, num_verts, 0);
   1.418 +	unsigned int *idxarr = mesh->set_index_data(num_tri * 3, 0);
   1.419 +
   1.420 +	static const Vector2 uv[] = { Vector2(0, 0), Vector2(1, 0), Vector2(1, 1), Vector2(0, 1) };
   1.421 +
   1.422 +	// front
   1.423 +	for(int i=0; i<4; i++) {
   1.424 +		*narr++ = Vector3(0, 0, 1);
   1.425 +		*tarr++ = Vector3(1, 0, 0);
   1.426 +		*uvarr++ = uv[i];
   1.427 +	}
   1.428 +	*varr++ = Vector3(-x, -y, z);
   1.429 +	*varr++ = Vector3(x, -y, z);
   1.430 +	*varr++ = Vector3(x, y, z);
   1.431 +	*varr++ = Vector3(-x, y, z);
   1.432 +	// right
   1.433 +	for(int i=0; i<4; i++) {
   1.434 +		*narr++ = Vector3(1, 0, 0);
   1.435 +		*tarr++ = Vector3(0, 0, -1);
   1.436 +		*uvarr++ = uv[i];
   1.437 +	}
   1.438 +	*varr++ = Vector3(x, -y, z);
   1.439 +	*varr++ = Vector3(x, -y, -z);
   1.440 +	*varr++ = Vector3(x, y, -z);
   1.441 +	*varr++ = Vector3(x, y, z);
   1.442 +	// back
   1.443 +	for(int i=0; i<4; i++) {
   1.444 +		*narr++ = Vector3(0, 0, -1);
   1.445 +		*tarr++ = Vector3(-1, 0, 0);
   1.446 +		*uvarr++ = uv[i];
   1.447 +	}
   1.448 +	*varr++ = Vector3(x, -y, -z);
   1.449 +	*varr++ = Vector3(-x, -y, -z);
   1.450 +	*varr++ = Vector3(-x, y, -z);
   1.451 +	*varr++ = Vector3(x, y, -z);
   1.452 +	// left
   1.453 +	for(int i=0; i<4; i++) {
   1.454 +		*narr++ = Vector3(-1, 0, 0);
   1.455 +		*tarr++ = Vector3(0, 0, 1);
   1.456 +		*uvarr++ = uv[i];
   1.457 +	}
   1.458 +	*varr++ = Vector3(-x, -y, -z);
   1.459 +	*varr++ = Vector3(-x, -y, z);
   1.460 +	*varr++ = Vector3(-x, y, z);
   1.461 +	*varr++ = Vector3(-x, y, -z);
   1.462 +	// top
   1.463 +	for(int i=0; i<4; i++) {
   1.464 +		*narr++ = Vector3(0, 1, 0);
   1.465 +		*tarr++ = Vector3(1, 0, 0);
   1.466 +		*uvarr++ = uv[i];
   1.467 +	}
   1.468 +	*varr++ = Vector3(-x, y, z);
   1.469 +	*varr++ = Vector3(x, y, z);
   1.470 +	*varr++ = Vector3(x, y, -z);
   1.471 +	*varr++ = Vector3(-x, y, -z);
   1.472 +	// bottom
   1.473 +	for(int i=0; i<4; i++) {
   1.474 +		*narr++ = Vector3(0, -1, 0);
   1.475 +		*tarr++ = Vector3(1, 0, 0);
   1.476 +		*uvarr++ = uv[i];
   1.477 +	}
   1.478 +	*varr++ = Vector3(-x, -y, -z);
   1.479 +	*varr++ = Vector3(x, -y, -z);
   1.480 +	*varr++ = Vector3(x, -y, z);
   1.481 +	*varr++ = Vector3(-x, -y, z);
   1.482 +
   1.483 +	// index array
   1.484 +	static const int faceidx[] = {0, 1, 2, 0, 2, 3};
   1.485 +	for(int i=0; i<num_faces; i++) {
   1.486 +		for(int j=0; j<6; j++) {
   1.487 +			*idxarr++ = faceidx[j] + i * 4;
   1.488 +		}
   1.489 +	}
   1.490 +}