nuclear@12: /*
nuclear@12: Printblobs - typography display hack
nuclear@12: Copyright (C) 2013  John Tsiombikas <nuclear@member.fsf.org>
nuclear@12: 
nuclear@12: This program is free software: you can redistribute it and/or modify
nuclear@12: it under the terms of the GNU General Public License as published by
nuclear@12: the Free Software Foundation, either version 3 of the License, or
nuclear@12: (at your option) any later version.
nuclear@12: 
nuclear@12: This program is distributed in the hope that it will be useful,
nuclear@12: but WITHOUT ANY WARRANTY; without even the implied warranty of
nuclear@12: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
nuclear@12: GNU General Public License for more details.
nuclear@12: 
nuclear@12: You should have received a copy of the GNU General Public License
nuclear@12: along with this program.  If not, see <http://www.gnu.org/licenses/>.
nuclear@12: */
nuclear@5: #include <vector>
nuclear@12: #include <math.h>
nuclear@5: #include "opengl.h"
nuclear@5: #include "mballs.h"
nuclear@5: #include "metasurf.h"
nuclear@9: #include "dsys.h"
nuclear@11: #include "udg.h"
nuclear@5: 
nuclear@5: struct MetaBall {
nuclear@12: 	float pos[3];
nuclear@5: 	float orbit;
nuclear@5: 	float energy;
nuclear@5: 	float phase_offs;
nuclear@5: };
nuclear@5: 
nuclear@5: #define VOL_SZ			2
nuclear@5: #define MBALL_GRID_SZ	50
nuclear@5: 
nuclear@9: static void update(float sec);
nuclear@5: static float calc_field(float x, float y, float z);
nuclear@5: static float eval(float x, float y, float z);
nuclear@5: static void vertex(float x, float y, float z);
nuclear@5: static void normal(float x, float y, float z);
nuclear@5: 
nuclear@5: static float grid[MBALL_GRID_SZ][MBALL_GRID_SZ][MBALL_GRID_SZ];
nuclear@5: static std::vector<MetaBall> balls;
nuclear@5: static struct metasurface *msurf;
nuclear@8: static float floor_height = -0.95;
nuclear@5: 
nuclear@11: static struct dsys_event *evrise;
nuclear@11: 
nuclear@5: bool mball_init()
nuclear@5: {
nuclear@5: 	static const float bbmin = -VOL_SZ / 2.0;
nuclear@5: 	static const float bbmax = VOL_SZ / 2.0;
nuclear@5: 
nuclear@5: 	if(!(msurf = msurf_create())) {
nuclear@5: 		return false;
nuclear@5: 	}
nuclear@5: 	msurf_threshold(msurf, 10);
nuclear@5: 	msurf_resolution(msurf, MBALL_GRID_SZ, MBALL_GRID_SZ, MBALL_GRID_SZ);
nuclear@5: 	msurf_bounds(msurf, bbmin, bbmin, bbmin, bbmax, bbmax, bbmax);
nuclear@5: 	msurf_eval_func(msurf, eval);
nuclear@5: 	msurf_vertex_func(msurf, vertex);
nuclear@5: 	//msurf_normal_func(msurf, normal);
nuclear@5: 
nuclear@5: 	for(int i=0; i<10; i++) {
nuclear@5: 		MetaBall mb;
nuclear@5: 		mb.orbit = 0.25 * rand() / (float)RAND_MAX + 0.35;
nuclear@9: 		mb.energy = 0.1 * rand() / (float)RAND_MAX + 0.15;
nuclear@5: 		mb.phase_offs = rand() / (float)RAND_MAX * M_PI * 2.0;
nuclear@5: 		balls.push_back(mb);
nuclear@5: 	}
nuclear@5: 
nuclear@11: 	evrise = dsys_event(demo, "mball_rise");
nuclear@11: 	dsys_set_event_eval(evrise, dsys_eval_sigmoid);
nuclear@11: 
nuclear@5: 	return true;
nuclear@5: }
nuclear@5: 
nuclear@9: void mball_render(float sec)
nuclear@5: {
nuclear@9: 	update(sec);
nuclear@5: 
nuclear@8: 	const float blue[] = {0.4, 0.45, 1.0, 1};
nuclear@8: 	const float dark_red[] = {0.6, 0.2, 0.1, 1};
nuclear@8: 	const float white[] = {1, 1, 1, 1};
nuclear@8: 	const float black[] = {0, 0, 0, 1};
nuclear@8: 
nuclear@5: 	glMatrixMode(GL_MODELVIEW);
nuclear@5: 	glPushMatrix();
nuclear@5: 	glScalef(4.0, 4.0, 4.0);
nuclear@5: 
nuclear@8: 	glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, blue);
nuclear@8: 	glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, white);
nuclear@8: 	glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, 80.0);
nuclear@8: 
nuclear@5: 	glBegin(GL_TRIANGLES);
nuclear@5: 	msurf_polygonize(msurf);
nuclear@5: 	glEnd();
nuclear@5: 
nuclear@8: 	// floor
nuclear@8: 	glBegin(GL_QUADS);
nuclear@8: 	glNormal3f(0, 1, 0);
nuclear@8: 	glVertex3f(-5, -1, 5);
nuclear@8: 	glVertex3f(5, -1, 5);
nuclear@8: 	glVertex3f(5, -1, -5);
nuclear@8: 	glVertex3f(-5, -1, -5);
nuclear@8: 	glEnd();
nuclear@8: 
nuclear@8: 	glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, dark_red);
nuclear@8: 	glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, black);
nuclear@8: 	glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, 80.0);
nuclear@8: 
nuclear@8: 	// box
nuclear@8: 	glPushMatrix();
nuclear@8: 	glTranslatef(0, -1.7, 1);
nuclear@8: 	glScalef(1.05, 1, 0.05);
nuclear@8: 	glutSolidCube(2.0);
nuclear@8: 	glPopMatrix();
nuclear@8: 
nuclear@8: 	glPushMatrix();
nuclear@8: 	glTranslatef(0, -1.7, -1);
nuclear@8: 	glScalef(1.05, 1, 0.05);
nuclear@8: 	glutSolidCube(2.0);
nuclear@8: 	glPopMatrix();
nuclear@8: 
nuclear@8: 	glPushMatrix();
nuclear@8: 	glTranslatef(1, -1.7, 0);
nuclear@8: 	glScalef(0.05, 1, 1);
nuclear@8: 	glutSolidCube(2.0);
nuclear@8: 	glPopMatrix();
nuclear@8: 
nuclear@8: 	glPushMatrix();
nuclear@8: 	glTranslatef(-1, -1.7, 0);
nuclear@8: 	glScalef(0.05, 1, 1);
nuclear@8: 	glutSolidCube(2.0);
nuclear@8: 	glPopMatrix();
nuclear@8: 
nuclear@5: 	glPopMatrix();
nuclear@5: }
nuclear@5: 
nuclear@5: 
nuclear@9: static void update(float sec)
nuclear@5: {
nuclear@11: 	float trise = dsys_event_value(evrise);
nuclear@11: 
nuclear@5: 	for(size_t i=0; i<balls.size(); i++) {
nuclear@5: 		float t = sec + balls[i].phase_offs;
nuclear@12: 		balls[i].pos[0] = cos(t * 1.8) * balls[i].orbit;
nuclear@12: 		balls[i].pos[2] = sin(t * 1.2) * balls[i].orbit;
nuclear@12: 		balls[i].pos[1] = (sin(t) + cos(t * 2.0) / 2.0 + sin(t * 3.0) / 3.0) * 0.45 - (2.0 - trise * 2.0);
nuclear@5: 	}
nuclear@5: 
nuclear@5: 	for(int i=0; i<MBALL_GRID_SZ; i++) {
nuclear@5: 		float x = (float)i / (float)MBALL_GRID_SZ * 2.0 - 1.0;
nuclear@5: 		for(int j=0; j<MBALL_GRID_SZ; j++) {
nuclear@5: 			float y = (float)j / (float)MBALL_GRID_SZ * 2.0 - 1.0;
nuclear@5: 			for(int k=0; k<MBALL_GRID_SZ; k++) {
nuclear@5: 				float z = (float)k / (float)MBALL_GRID_SZ * 2.0 - 1.0;
nuclear@5: 				grid[i][j][k] = calc_field(x, y, z);
nuclear@5: 			}
nuclear@5: 		}
nuclear@5: 	}
nuclear@5: }
nuclear@5: 
nuclear@5: static float calc_field(float x, float y, float z)
nuclear@5: {
nuclear@5: 	float sum = 0.0f;
nuclear@5: 	for(size_t i=0; i<balls.size(); i++) {
nuclear@12: 		float dx = balls[i].pos[0] - x;
nuclear@12: 		float dy = balls[i].pos[1] - y;
nuclear@12: 		float dz = balls[i].pos[2] - z;
nuclear@12: 		float dist_sq = dx * dx + dy * dy + dz * dz;
nuclear@5: 		if(dist_sq > 1e-6) {
nuclear@5: 			sum += balls[i].energy / dist_sq;
nuclear@5: 		} else {
nuclear@5: 			sum += 1000.0;
nuclear@5: 		}
nuclear@5: 	}
nuclear@8: 
nuclear@8: 	// floor
nuclear@8: 	float height = y - floor_height;
nuclear@8: 	if(height > 1e-6) {
nuclear@8: 		sum += 1.0 / height;
nuclear@8: 	} else {
nuclear@8: 		sum += 1000.0;
nuclear@8: 	}
nuclear@8: 
nuclear@5: 	return sum;
nuclear@5: }
nuclear@5: 
nuclear@5: static inline int clamp(int x, int a, int b)
nuclear@5: {
nuclear@5: 	return x < a ? a : (x > b ? b : x);
nuclear@5: }
nuclear@5: 
nuclear@5: static float eval(float x, float y, float z)
nuclear@5: {
nuclear@5: 	int cell_x = clamp((int)((x / VOL_SZ + 0.5) * MBALL_GRID_SZ), 0, MBALL_GRID_SZ - 1);
nuclear@5: 	int cell_y = clamp((int)((y / VOL_SZ + 0.5) * MBALL_GRID_SZ), 0, MBALL_GRID_SZ - 1);
nuclear@5: 	int cell_z = clamp((int)((z / VOL_SZ + 0.5) * MBALL_GRID_SZ), 0, MBALL_GRID_SZ - 1);
nuclear@5: 
nuclear@5: 	return grid[cell_x][cell_y][cell_z];
nuclear@5: }
nuclear@5: 
nuclear@5: static void vertex(float x, float y, float z)
nuclear@5: {
nuclear@5: 	float delta = (float)VOL_SZ / (float)MBALL_GRID_SZ;
nuclear@5: 
nuclear@5: 	float dfdx = calc_field(x - delta, y, z) - calc_field(x + delta, y, z);
nuclear@5: 	float dfdy = calc_field(x, y - delta, z) - calc_field(x, y + delta, z);
nuclear@5: 	float dfdz = calc_field(x, y, z - delta) - calc_field(x, y, z + delta);
nuclear@5: 
nuclear@5: 	float len = sqrt(dfdx * dfdx + dfdy * dfdy + dfdz * dfdz);
nuclear@5: 
nuclear@5: 	glNormal3f(dfdx / len, dfdy / len, dfdz / len);
nuclear@5: 	glVertex3f(x, y, z);
nuclear@5: }
nuclear@5: 
nuclear@5: static void normal(float x, float y, float z)
nuclear@5: {
nuclear@5: 	glNormal3f(x, y, z);
nuclear@5: }