libgender/util.C

/*
 * math support
 * most of the more complicated code is taken from mesa.
 */

#include <cstdio> // ugly
#include <cmath>

#include <sys/time.h>
#include <time.h>

#include <GL/gl.h>
#include <GL/glut.h>

#include "util.h"
#include "entity.h"

#define DEG2RAD (M_PI / 180.)

void renormalize (sector &s, point &p)
{
  float i;

  p.x = modff (p.x, &i); s.x += (soffs)i;
  p.y = modff (p.y, &i); s.y += (soffs)i;
  p.z = modff (p.z, &i); s.z += (soffs)i;
}

/////////////////////////////////////////////////////////////////////////////

const vec3 normalize (const vec3 &v)
{
  GLfloat s = abs (v);

  if (!s)
    return v;

  s = 1. / s;
  return vec3 (v.x * s, v.y * s, v.z * s);
}

const vec3 cross (const vec3 &a, const vec3 &b)
{
  return vec3 (
     a.y * b.z - a.z * b.y,
     a.z * b.x - a.x * b.z,
     a.x * b.y - a.y * b.x
  );
}

/////////////////////////////////////////////////////////////////////////////

void matrix::diagonal (GLfloat v)
{
  for (int i = 4; i--; )
    for (int j = 4; j--; )
      data[i][j] = i == j ? v : 0.;
}

const matrix operator *(const matrix &a, const matrix &b)
{
  matrix r;

  // taken from mesa
  for (int i = 0; i < 4; i++)
    {
      const GLfloat ai0=a(i,0), ai1=a(i,1), ai2=a(i,2), ai3=a(i,3);

      r(i,0) = ai0 * b(0,0) + ai1 * b(1,0) + ai2 * b(2,0) + ai3 * b(3,0);
      r(i,1) = ai0 * b(0,1) + ai1 * b(1,1) + ai2 * b(2,1) + ai3 * b(3,1);
      r(i,2) = ai0 * b(0,2) + ai1 * b(1,2) + ai2 * b(2,2) + ai3 * b(3,2);
      r(i,3) = ai0 * b(0,3) + ai1 * b(1,3) + ai2 * b(2,3) + ai3 * b(3,3);
    }

  return r;
}

const matrix matrix::rotation (GLfloat angle, const vec3 &axis)
{
  GLfloat xx, yy, zz, xy, yz, zx, xs, ys, zs, one_c, s, c;

  s = (GLfloat) sinf (angle * DEG2RAD);
  c = (GLfloat) cosf (angle * DEG2RAD);

  const GLfloat mag = abs (axis);

  if (mag <= 1.0e-4)
    return matrix (1);

  matrix m;
  const vec3 n = axis * (1. / mag);

  xx = n.x * n.x;
  yy = n.y * n.y;
  zz = n.z * n.z;
  xy = n.x * n.y;
  yz = n.y * n.z;
  zx = n.z * n.x;
  xs = n.x * s;
  ys = n.y * s;
  zs = n.z * s;
  one_c = 1.0F - c;

  m(0,0) = (one_c * xx) + c;
  m(0,1) = (one_c * xy) - zs;
  m(0,2) = (one_c * zx) + ys;
  m(0,3) = 0;
  
  m(1,0) = (one_c * xy) + zs;
  m(1,1) = (one_c * yy) + c;
  m(1,2) = (one_c * yz) - xs;
  m(1,3) = 0;
  
  m(2,0) = (one_c * zx) - ys;
  m(2,1) = (one_c * yz) + xs;
  m(2,2) = (one_c * zz) + c;
  m(2,3) = 0;
  
  m(3,0) = 0;
  m(3,1) = 0;
  m(3,2) = 0;
  m(3,3) = 1;

  return m;
}

const vec3 operator *(const matrix &a, const vec3 &v)
{
  return vec3 (
    a(0,0) * v.x + a(0,1) * v.y + a(0,2) * v.z + a(0,3),
    a(1,0) * v.x + a(1,1) * v.y + a(1,2) * v.z + a(1,3),
    a(2,0) * v.x + a(2,1) * v.y + a(2,2) * v.z + a(2,3)
  );
}

void matrix::print ()
{
  printf ("\n");
  printf ("[ %f, %f, %f, %f ]\n", data[0][0], data[1][0], data[2][0], data[3][0]);
  printf ("[ %f, %f, %f, %f ]\n", data[0][1], data[1][1], data[2][1], data[3][1]);
  printf ("[ %f, %f, %f, %f ]\n", data[0][2], data[1][2], data[2][2], data[3][2]);
  printf ("[ %f, %f, %f, %f ]\n", data[0][3], data[1][3], data[2][3], data[3][3]);
}

const matrix matrix::translation (const vec3 &v)
{
  matrix m(1);

  m(0,3) = v.x;
  m(1,3) = v.y;
  m(2,3) = v.z;

  return m;
}

/////////////////////////////////////////////////////////////////////////////

plane::plane (GLfloat a, GLfloat b, GLfloat c, GLfloat d)
: n (vec3 (a,b,c))
{
  GLfloat s = 1. / abs (n);

  n = n * s;
  this->d = d * s;
}

/////////////////////////////////////////////////////////////////////////////

void box::add (const box &o)
{
  a.x = min (a.x, o.a.x);
  a.y = min (a.y, o.a.y);
  a.z = min (a.z, o.a.z);
  b.x = max (b.x, o.b.x);
  b.y = max (b.y, o.b.y);
  b.z = max (b.z, o.b.z);
}

void box::add (const point &p)
{
  a.x = min (a.x, p.x);
  a.y = min (a.y, p.y);
  a.z = min (a.z, p.z);
  b.x = max (b.x, p.x);
  b.y = max (b.y, p.y);
  b.z = max (b.z, p.z);
}

/////////////////////////////////////////////////////////////////////////////

struct timer timer;
static double base;
double timer::now = 0.;
double timer::diff;

void timer::frame ()
{
  struct timeval tv;
  gettimeofday (&tv, 0);

  double next = tv.tv_sec - base + tv.tv_usec / 1.e6;

  diff = next - now;
  now = next;
}

timer::timer ()
{
  struct timeval tv;
  gettimeofday (&tv, 0);
  base = tv.tv_sec + tv.tv_usec / 1.e6;
}

GLuint SDL_GL_LoadTexture (SDL_Surface * surface, GLfloat * texcoord)
{
  GLuint texture;
  int w, h;
  SDL_Surface *image;
  SDL_Rect area;
  Uint32 saved_flags;
  Uint8 saved_alpha;

  /* Use the surface width and height expanded to powers of 2 */
  //w = power_of_two (surface->w);
  //h = power_of_two (surface->h);
  w = power_of_two (surface->w);
  h = power_of_two (surface->h);
  texcoord[0] = 0.0f;           /* Min X */
  texcoord[1] = 0.0f;           /* Min Y */
  texcoord[2] = (GLfloat) surface->w / w;       /* Max X */
  texcoord[3] = (GLfloat) surface->h / h;       /* Max Y */

  image = SDL_CreateRGBSurface (SDL_SWSURFACE, w, h, 32,
#if SDL_BYTEORDER == SDL_LIL_ENDIAN     /* OpenGL RGBA masks */
                                0x000000FF, 0x0000FF00, 0x00FF0000, 0xFF000000
#else
                                0xFF000000, 0x00FF0000, 0x0000FF00, 0x000000FF
#endif
    );
  if (image == NULL)
    {
      return 0;
    }

  /* Save the alpha blending attributes */
  saved_flags = surface->flags & (SDL_SRCALPHA | SDL_RLEACCELOK);
  saved_alpha = surface->format->alpha;
  if ((saved_flags & SDL_SRCALPHA) == SDL_SRCALPHA)
    {
      SDL_SetAlpha (surface, 0, 0);
    }

  /* Copy the surface into the GL texture image */
  area.x = 0;
  area.y = 0;
  area.w = surface->w;
  area.h = surface->h;
  SDL_BlitSurface (surface, &area, image, &area);

  /* Restore the alpha blending attributes */
  if ((saved_flags & SDL_SRCALPHA) == SDL_SRCALPHA)
    {
      SDL_SetAlpha (surface, saved_flags, saved_alpha);
    }

  /* Create an OpenGL texture for the image */
  glGenTextures (1, &texture);
  glBindTexture (GL_TEXTURE_2D, texture);
  glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  glTexImage2D (GL_TEXTURE_2D,
                0,
                GL_RGBA, w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, image->pixels);
  SDL_FreeSurface (image);      /* No longer needed */

  return texture;
}

void render_text (GLint x, GLint y, const char *str)
{
  glRasterPos2i (x, y);

  while (!*str)
    glutBitmapCharacter (GLUT_BITMAP_HELVETICA_18, *str++);
}

//skedjuhlar main_scheduler;

Revision:	1.20
Committed:	Fri Oct 8 17:40:26 2004 UTC (19 years, 7 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.19:	+10 -0 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.3	/*
2			* math support
3			* most of the more complicated code is taken from mesa.
4			*/
5
6	root	1.2	#include <cstdio> // ugly
7	root	1.1	#include <cmath>
8
9	root	1.4	#include <sys/time.h>
10			#include <time.h>
11	root	1.20
12	root	1.15	#include <GL/gl.h>
13	root	1.20	#include <GL/glut.h>
14	root	1.2
15	root	1.1	#include "util.h"
16	root	1.15	#include "entity.h"
17	root	1.1
18	root	1.3	#define DEG2RAD (M_PI / 180.)
19
20	root	1.6	void renormalize (sector &s, point &p)
21			{
22			float i;
23
24	root	1.11	p.x = modff (p.x, &i); s.x += (soffs)i;
25			p.y = modff (p.y, &i); s.y += (soffs)i;
26			p.z = modff (p.z, &i); s.z += (soffs)i;
27	root	1.6	}
28
29	root	1.7	/////////////////////////////////////////////////////////////////////////////
30
31	root	1.1	const vec3 normalize (const vec3 &v)
32			{
33	root	1.3	GLfloat s = abs (v);
34
35			if (!s)
36			return v;
37	root	1.1
38	root	1.3	s = 1. / s;
39	root	1.1	return vec3 (v.x * s, v.y * s, v.z * s);
40			}
41
42			const vec3 cross (const vec3 &a, const vec3 &b)
43			{
44			return vec3 (
45	root	1.3	a.y * b.z - a.z * b.y,
46			a.z * b.x - a.x * b.z,
47			a.x * b.y - a.y * b.x
48			);
49	root	1.2	}
50
51	root	1.7	/////////////////////////////////////////////////////////////////////////////
52
53	root	1.12	void matrix::diagonal (GLfloat v)
54	root	1.2	{
55			for (int i = 4; i--; )
56			for (int j = 4; j--; )
57			data[i][j] = i == j ? v : 0.;
58			}
59
60	root	1.12	const matrix operator *(const matrix &a, const matrix &b)
61	root	1.2	{
62	root	1.12	matrix r;
63	root	1.2
64	root	1.3	// taken from mesa
65			for (int i = 0; i < 4; i++)
66			{
67			const GLfloat ai0=a(i,0), ai1=a(i,1), ai2=a(i,2), ai3=a(i,3);
68
69			r(i,0) = ai0 * b(0,0) + ai1 * b(1,0) + ai2 * b(2,0) + ai3 * b(3,0);
70			r(i,1) = ai0 * b(0,1) + ai1 * b(1,1) + ai2 * b(2,1) + ai3 * b(3,1);
71			r(i,2) = ai0 * b(0,2) + ai1 * b(1,2) + ai2 * b(2,2) + ai3 * b(3,2);
72			r(i,3) = ai0 * b(0,3) + ai1 * b(1,3) + ai2 * b(2,3) + ai3 * b(3,3);
73			}
74	root	1.2
75	root	1.3	return r;
76			}
77	root	1.2
78	root	1.12	const matrix matrix::rotation (GLfloat angle, const vec3 &axis)
79	root	1.3	{
80			GLfloat xx, yy, zz, xy, yz, zx, xs, ys, zs, one_c, s, c;
81	root	1.2
82	root	1.3	s = (GLfloat) sinf (angle * DEG2RAD);
83			c = (GLfloat) cosf (angle * DEG2RAD);
84
85			const GLfloat mag = abs (axis);
86
87			if (mag <= 1.0e-4)
88	root	1.12	return matrix (1);
89	root	1.3
90	root	1.12	matrix m;
91	root	1.3	const vec3 n = axis * (1. / mag);
92
93			xx = n.x * n.x;
94			yy = n.y * n.y;
95			zz = n.z * n.z;
96			xy = n.x * n.y;
97			yz = n.y * n.z;
98			zx = n.z * n.x;
99			xs = n.x * s;
100			ys = n.y * s;
101			zs = n.z * s;
102			one_c = 1.0F - c;
103
104			m(0,0) = (one_c * xx) + c;
105			m(0,1) = (one_c * xy) - zs;
106			m(0,2) = (one_c * zx) + ys;
107			m(0,3) = 0;
108
109			m(1,0) = (one_c * xy) + zs;
110			m(1,1) = (one_c * yy) + c;
111			m(1,2) = (one_c * yz) - xs;
112			m(1,3) = 0;
113
114			m(2,0) = (one_c * zx) - ys;
115			m(2,1) = (one_c * yz) + xs;
116			m(2,2) = (one_c * zz) + c;
117			m(2,3) = 0;
118
119			m(3,0) = 0;
120			m(3,1) = 0;
121			m(3,2) = 0;
122			m(3,3) = 1;
123
124	root	1.9	return m;
125	root	1.3	}
126
127	root	1.12	const vec3 operator *(const matrix &a, const vec3 &v)
128	root	1.3	{
129			return vec3 (
130	root	1.9	a(0,0) * v.x + a(0,1) * v.y + a(0,2) * v.z + a(0,3),
131			a(1,0) * v.x + a(1,1) * v.y + a(1,2) * v.z + a(1,3),
132			a(2,0) * v.x + a(2,1) * v.y + a(2,2) * v.z + a(2,3)
133	root	1.3	);
134	root	1.2	}
135
136	root	1.12	void matrix::print ()
137	root	1.2	{
138			printf ("\n");
139			printf ("[ %f, %f, %f, %f ]\n", data[0][0], data[1][0], data[2][0], data[3][0]);
140			printf ("[ %f, %f, %f, %f ]\n", data[0][1], data[1][1], data[2][1], data[3][1]);
141			printf ("[ %f, %f, %f, %f ]\n", data[0][2], data[1][2], data[2][2], data[3][2]);
142			printf ("[ %f, %f, %f, %f ]\n", data[0][3], data[1][3], data[2][3], data[3][3]);
143			}
144
145	root	1.12	const matrix matrix::translation (const vec3 &v)
146	root	1.2	{
147	root	1.12	matrix m(1);
148	root	1.2
149	root	1.9	m(0,3) = v.x;
150			m(1,3) = v.y;
151			m(2,3) = v.z;
152	root	1.2
153	root	1.9	return m;
154	root	1.1	}
155
156	root	1.7	/////////////////////////////////////////////////////////////////////////////
157
158			plane::plane (GLfloat a, GLfloat b, GLfloat c, GLfloat d)
159	root	1.9	: n (vec3 (a,b,c))
160	root	1.7	{
161			GLfloat s = 1. / abs (n);
162
163			n = n * s;
164	root	1.9	this->d = d * s;
165	root	1.7	}
166
167			/////////////////////////////////////////////////////////////////////////////
168
169	root	1.1	void box::add (const box &o)
170			{
171			a.x = min (a.x, o.a.x);
172			a.y = min (a.y, o.a.y);
173			a.z = min (a.z, o.a.z);
174			b.x = max (b.x, o.b.x);
175			b.y = max (b.y, o.b.y);
176			b.z = max (b.z, o.b.z);
177			}
178
179	root	1.19	void box::add (const point &p)
180	root	1.1	{
181			a.x = min (a.x, p.x);
182			a.y = min (a.y, p.y);
183			a.z = min (a.z, p.z);
184			b.x = max (b.x, p.x);
185			b.y = max (b.y, p.y);
186			b.z = max (b.z, p.z);
187	root	1.5	}
188
189	root	1.7	/////////////////////////////////////////////////////////////////////////////
190	root	1.4
191			struct timer timer;
192			static double base;
193			double timer::now = 0.;
194			double timer::diff;
195
196			void timer::frame ()
197			{
198			struct timeval tv;
199			gettimeofday (&tv, 0);
200
201			double next = tv.tv_sec - base + tv.tv_usec / 1.e6;
202
203			diff = next - now;
204			now = next;
205			}
206
207			timer::timer ()
208			{
209			struct timeval tv;
210			gettimeofday (&tv, 0);
211			base = tv.tv_sec + tv.tv_usec / 1.e6;
212			}
213
214	root	1.13	GLuint SDL_GL_LoadTexture (SDL_Surface * surface, GLfloat * texcoord)
215			{
216			GLuint texture;
217			int w, h;
218			SDL_Surface *image;
219			SDL_Rect area;
220			Uint32 saved_flags;
221			Uint8 saved_alpha;
222
223			/* Use the surface width and height expanded to powers of 2 */
224	root	1.14	//w = power_of_two (surface->w);
225			//h = power_of_two (surface->h);
226	root	1.13	w = power_of_two (surface->w);
227			h = power_of_two (surface->h);
228			texcoord[0] = 0.0f; /* Min X */
229			texcoord[1] = 0.0f; /* Min Y */
230			texcoord[2] = (GLfloat) surface->w / w; /* Max X */
231			texcoord[3] = (GLfloat) surface->h / h; /* Max Y */
232
233			image = SDL_CreateRGBSurface (SDL_SWSURFACE, w, h, 32,
234			#if SDL_BYTEORDER == SDL_LIL_ENDIAN /* OpenGL RGBA masks */
235			0x000000FF, 0x0000FF00, 0x00FF0000, 0xFF000000
236			#else
237			0xFF000000, 0x00FF0000, 0x0000FF00, 0x000000FF
238			#endif
239			);
240			if (image == NULL)
241			{
242			return 0;
243			}
244
245			/* Save the alpha blending attributes */
246			saved_flags = surface->flags & (SDL_SRCALPHA \| SDL_RLEACCELOK);
247			saved_alpha = surface->format->alpha;
248			if ((saved_flags & SDL_SRCALPHA) == SDL_SRCALPHA)
249			{
250			SDL_SetAlpha (surface, 0, 0);
251			}
252
253			/* Copy the surface into the GL texture image */
254			area.x = 0;
255			area.y = 0;
256			area.w = surface->w;
257			area.h = surface->h;
258			SDL_BlitSurface (surface, &area, image, &area);
259
260			/* Restore the alpha blending attributes */
261			if ((saved_flags & SDL_SRCALPHA) == SDL_SRCALPHA)
262			{
263			SDL_SetAlpha (surface, saved_flags, saved_alpha);
264			}
265
266			/* Create an OpenGL texture for the image */
267			glGenTextures (1, &texture);
268			glBindTexture (GL_TEXTURE_2D, texture);
269			glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
270			glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
271			glTexImage2D (GL_TEXTURE_2D,
272			0,
273			GL_RGBA, w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, image->pixels);
274			SDL_FreeSurface (image); /* No longer needed */
275
276			return texture;
277	root	1.20	}
278
279			void render_text (GLint x, GLint y, const char *str)
280			{
281			glRasterPos2i (x, y);
282
283			while (!*str)
284			glutBitmapCharacter (GLUT_BITMAP_HELVETICA_18, *str++);
285	root	1.15	}
286	root	1.13
287	root	1.10	//skedjuhlar main_scheduler;
288	root	1.17