/* * This program is under the GNU GPL. * Use at your own risk. * * written by David Bucciarelli (tech.hmw@plus.it) * Humanware s.r.l. * * based on a Mikael SkiZoWalker's (MoDEL) / France (Skizo@Hol.Fr) demo */ #include <stdio.h> #include <math.h> #include <stdlib.h> #include <string.h> #include <time.h> #ifdef WIN32 #include <windows.h> #endif #include <GL/glut.h> #ifdef XMESA #include "GL/xmesa.h" static int fullscreen = 1; #endif #ifndef M_PI #define M_PI 3.14159265 #endif #define heightMnt 450 #define lenghtXmnt 62 #define lenghtYmnt 62 #define stepXmnt 96.0 #define stepYmnt 96.0 #define WIDTH 640 #define HEIGHT 480 static GLint T0 = 0; static GLint Frames = 0; #define TSCALE 4 #define FOV 85 static GLfloat terrain[256 * 256]; static GLfloat terraincolor[256 * 256][3]; static int win = 0; static int fog = 1; static int bfcull = 1; static int usetex = 1; static int poutline = 0; static int help = 1; static int joyavailable = 0; static int joyactive = 0; static float ModZMnt; static long GlobalMnt = 0; static int scrwidth = WIDTH; static int scrheight = HEIGHT; #define OBSSTARTX 992.0 #define OBSSTARTY 103.0 static float obs[3] = { OBSSTARTX, heightMnt * 1.3, OBSSTARTY }; static float dir[3], v1[2], v2[2]; static float v = 900.0; static float alpha = 75.0; static float beta = 90.0; static void calcposobs(void) { float alpha1, alpha2; static double t0 = -1.; double dt, t = glutGet(GLUT_ELAPSED_TIME) / 1000.0; if (t0 < 0.0) t0 = t; dt = t - t0; t0 = t; dir[0] = sin(alpha * M_PI / 180.0); dir[2] = cos(alpha * M_PI / 180.0) * sin(beta * M_PI / 180.0); dir[1] = cos(beta * M_PI / 180.0); if (dir[0] < 1.0e-5 && dir[0] > -1.0e-5) dir[0] = 0; if (dir[1] < 1.0e-5 && dir[1] > -1.0e-5) dir[1] = 0; if (dir[2] < 1.0e-5 && dir[2] > -1.0e-5) dir[2] = 0; alpha1 = alpha + FOV / 2.0; v1[0] = sin(alpha1 * M_PI / 180.0); v1[1] = cos(alpha1 * M_PI / 180.0); alpha2 = alpha - FOV / 2.0; v2[0] = sin(alpha2 * M_PI / 180.0); v2[1] = cos(alpha2 * M_PI / 180.0); obs[0] += v * dir[0] * dt; obs[1] += v * dir[1] * dt; obs[2] += v * dir[2] * dt; if (obs[1] < 0.0) obs[1] = 0.0; } static void reshape(int width, int height) { scrwidth = width; scrheight = height; glViewport(0, 0, (GLint) width, (GLint) height); glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluPerspective(50.0, ((GLfloat) width / (GLfloat) height), lenghtXmnt * stepYmnt * 0.01, lenghtXmnt * stepYmnt * 0.7); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); } static int clipstrip(float y, float *start, float *end) { float x1, x2, t1, t2, tmp; if (v1[1] == 0.0) { t1 = 0.0; x1 = -HUGE_VAL; } else { t1 = y / v1[1]; x1 = t1 * v1[0]; } if (v2[1] == 0.0) { t2 = 0.0; x2 = HUGE_VAL; } else { t2 = y / v2[1]; x2 = t2 * v2[0]; } if (((x1 < -(lenghtXmnt * stepXmnt) / 2) && (t2 <= 0.0)) || ((t1 <= 0.0) && (x2 > (lenghtXmnt * stepXmnt) / 2)) || ((t1 < 0.0) && (t2 < 0.0))) return 0; if ((t1 == 0.0) && (t2 == 0.0)) { if ((v1[0] < 0.0) && (v1[1] > 0.0) && (v2[0] < 0.0) && (v2[1] < 0.0)) { *start = -(lenghtXmnt * stepXmnt) / 2; *end = stepXmnt; return 1; } else { if ((v1[0] > 0.0) && (v1[1] < 0.0) && (v2[0] > 0.0) && (v2[1] > 0.0)) { *start = -stepXmnt; *end = (lenghtXmnt * stepXmnt) / 2; return 1; } else return 0; } } else { if (t2 < 0.0) { if (x1 < 0.0) x2 = -(lenghtXmnt * stepXmnt) / 2; else x2 = (lenghtXmnt * stepXmnt) / 2; } if (t1 < 0.0) { if (x2 < 0.0) x1 = -(lenghtXmnt * stepXmnt) / 2; else x1 = (lenghtXmnt * stepXmnt) / 2; } } if (x1 > x2) { tmp = x1; x1 = x2; x2 = tmp; } x1 -= stepXmnt; if (x1 < -(lenghtXmnt * stepXmnt) / 2) x1 = -(lenghtXmnt * stepXmnt) / 2; x2 += stepXmnt; if (x2 > (lenghtXmnt * stepXmnt) / 2) x2 = (lenghtXmnt * stepXmnt) / 2; *start = ((int) (x1 / stepXmnt)) * stepXmnt; *end = ((int) (x2 / stepXmnt)) * stepXmnt; return 1; } static void printstring(void *font, char *string) { int len, i; len = (int) strlen(string); for (i = 0; i < len; i++) glutBitmapCharacter(font, string[i]); } static void printhelp(void) { glEnable(GL_BLEND); glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); glColor4f(0.0, 0.0, 0.0, 0.5); glRecti(40, 40, 600, 440); glDisable(GL_BLEND); glColor3f(1.0, 0.0, 0.0); glRasterPos2i(300, 420); printstring(GLUT_BITMAP_TIMES_ROMAN_24, "Help"); glRasterPos2i(60, 390); printstring(GLUT_BITMAP_TIMES_ROMAN_24, "h - Toggle Help"); glRasterPos2i(60, 360); printstring(GLUT_BITMAP_TIMES_ROMAN_24, "t - Toggle Textures"); glRasterPos2i(60, 330); printstring(GLUT_BITMAP_TIMES_ROMAN_24, "f - Toggle Fog"); glRasterPos2i(60, 300); printstring(GLUT_BITMAP_TIMES_ROMAN_24, "p - Wire frame"); glRasterPos2i(60, 270); printstring(GLUT_BITMAP_TIMES_ROMAN_24, "b - Toggle Back face culling"); glRasterPos2i(60, 240); printstring(GLUT_BITMAP_TIMES_ROMAN_24, "Arrow Keys - Rotate"); glRasterPos2i(60, 210); printstring(GLUT_BITMAP_TIMES_ROMAN_24, "a - Increase velocity"); glRasterPos2i(60, 180); printstring(GLUT_BITMAP_TIMES_ROMAN_24, "z - Decrease velocity"); glRasterPos2i(60, 150); if (joyavailable) printstring(GLUT_BITMAP_TIMES_ROMAN_24, "j - Toggle jostick control (Joystick control available)"); else printstring(GLUT_BITMAP_TIMES_ROMAN_24, "(No Joystick control available)"); } static void drawterrain(void) { int h, i, idx, ox, oy; float j, k, start, end; ox = (int) (obs[0] / stepXmnt); oy = (int) (obs[2] / stepYmnt); GlobalMnt = ((ox * TSCALE) & 255) + ((oy * TSCALE) & 255) * 256; glPushMatrix(); glTranslatef((float) ox * stepXmnt, 0, (float) oy * stepYmnt); for (h = 0, k = -(lenghtYmnt * stepYmnt) / 2; h < lenghtYmnt; k += stepYmnt, h++) { if (!clipstrip(k, &start, &end)) continue; glBegin(GL_TRIANGLE_STRIP); /* I hope that the optimizer will be able to improve this code */ for (i = (int) (lenghtXmnt / 2 + start / stepXmnt), j = start; j <= end; j += stepXmnt, i++) { idx = (i * TSCALE + h * 256 * TSCALE + GlobalMnt) & 65535; glColor3fv(terraincolor[idx]); glTexCoord2f((ox + i) / 8.0, (oy + h) / 8.0); glVertex3f(j, terrain[idx], k); idx = (i * TSCALE + h * 256 * TSCALE + 256 * TSCALE + GlobalMnt) & 65535; glColor3fv(terraincolor[idx]); glTexCoord2f((ox + i) / 8.0, (oy + h + 1) / 8.0); glVertex3f(j, terrain[idx], k + stepYmnt); } glEnd(); } glDisable(GL_CULL_FACE); glDisable(GL_TEXTURE_2D); glEnable(GL_BLEND); glBegin(GL_QUADS); glColor4f(0.1, 0.7, 1.0, 0.4); glVertex3f(-(lenghtXmnt * stepXmnt) / 2.0, heightMnt * 0.6, -(lenghtYmnt * stepYmnt) / 2.0); glVertex3f(-(lenghtXmnt * stepXmnt) / 2.0, heightMnt * 0.6, (lenghtYmnt * stepYmnt) / 2.0); glVertex3f((lenghtXmnt * stepXmnt) / 2.0, heightMnt * 0.6, (lenghtYmnt * stepYmnt) / 2.0); glVertex3f((lenghtXmnt * stepXmnt) / 2.0, heightMnt * 0.6, -(lenghtYmnt * stepYmnt) / 2.0); glEnd(); glDisable(GL_BLEND); if (bfcull) glEnable(GL_CULL_FACE); glEnable(GL_TEXTURE_2D); glPopMatrix(); } static void dojoy(void) { #ifdef WIN32 static UINT max[2] = { 0, 0 }; static UINT min[2] = { 0xffffffff, 0xffffffff }, center[2]; MMRESULT res; JOYINFO joy; res = joyGetPos(JOYSTICKID1, &joy); if (res == JOYERR_NOERROR) { joyavailable = 1; if (max[0] < joy.wXpos) max[0] = joy.wXpos; if (min[0] > joy.wXpos) min[0] = joy.wXpos; center[0] = (max[0] + min[0]) / 2; if (max[1] < joy.wYpos) max[1] = joy.wYpos; if (min[1] > joy.wYpos) min[1] = joy.wYpos; center[1] = (max[1] + min[1]) / 2; if (joyactive) { if (fabs(center[0] - (float) joy.wXpos) > 0.1 * (max[0] - min[0])) alpha += 2.5 * (center[0] - (float) joy.wXpos) / (max[0] - min[0]); if (fabs(center[1] - (float) joy.wYpos) > 0.1 * (max[1] - min[1])) beta += 2.5 * (center[1] - (float) joy.wYpos) / (max[1] - min[1]); if (joy.wButtons & JOY_BUTTON1) v += 0.5; if (joy.wButtons & JOY_BUTTON2) v -= 0.5; } } else joyavailable = 0; #endif } static void drawscene(void) { static char frbuf[80] = ""; dojoy(); glShadeModel(GL_SMOOTH); glEnable(GL_DEPTH_TEST); if (usetex) glEnable(GL_TEXTURE_2D); else glDisable(GL_TEXTURE_2D); if (fog) glEnable(GL_FOG); else glDisable(GL_FOG); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glPushMatrix(); calcposobs(); gluLookAt(obs[0], obs[1], obs[2], obs[0] + dir[0], obs[1] + dir[1], obs[2] + dir[2], 0.0, 1.0, 0.0); drawterrain(); glPopMatrix(); glDisable(GL_TEXTURE_2D); glDisable(GL_DEPTH_TEST); glDisable(GL_FOG); glShadeModel(GL_FLAT); glMatrixMode(GL_PROJECTION); glLoadIdentity(); glOrtho(-0.5, 639.5, -0.5, 479.5, -1.0, 1.0); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glColor3f(1.0, 0.0, 0.0); glRasterPos2i(10, 10); printstring(GLUT_BITMAP_HELVETICA_18, frbuf); glRasterPos2i(350, 470); printstring(GLUT_BITMAP_HELVETICA_10, "Terrain V1.2 Written by David Bucciarelli (tech.hmw@plus.it)"); glRasterPos2i(434, 457); printstring(GLUT_BITMAP_HELVETICA_10, "Based on a Mickael's demo (Skizo@Hol.Fr)"); if (help) printhelp(); reshape(scrwidth, scrheight); glutSwapBuffers(); Frames++; { GLint t = glutGet(GLUT_ELAPSED_TIME); if (t - T0 >= 2000) { GLfloat seconds = (t - T0) / 1000.0; GLfloat fps = Frames / seconds; sprintf(frbuf, "Frame rate: %f", fps); T0 = t; Frames = 0; } } } static void key(unsigned char k, int x, int y) { switch (k) { case 27: exit(0); break; case 'a': v += 50.; break; case 'z': v -= 50.; break; case 'p': if (poutline) { glPolygonMode(GL_FRONT_AND_BACK, GL_FILL); poutline = 0; } else { glPolygonMode(GL_FRONT_AND_BACK, GL_LINE); poutline = 1; } break; case 'j': joyactive = (!joyactive); break; case 'h': help = (!help); break; case 'f': fog = (!fog); break; case 't': usetex = (!usetex); break; case 'b': if (bfcull) { glDisable(GL_CULL_FACE); bfcull = 0; } else { glEnable(GL_CULL_FACE); bfcull = 1; } break; #ifdef XMESA case ' ': XMesaSetFXmode(fullscreen ? XMESA_FX_FULLSCREEN : XMESA_FX_WINDOW); fullscreen = (!fullscreen); break; #endif } } static void special(int k, int x, int y) { switch (k) { case GLUT_KEY_LEFT: alpha += 2.0; break; case GLUT_KEY_RIGHT: alpha -= 2.0; break; case GLUT_KEY_DOWN: beta -= 2.0; break; case GLUT_KEY_UP: beta += 2.0; break; } } static void calccolor(GLfloat height, GLfloat c[3]) { GLfloat color[4][3] = { {1.0, 1.0, 1.0}, {0.0, 0.8, 0.0}, {1.0, 1.0, 0.3}, {0.0, 0.0, 0.8} }; GLfloat fact; height = height * (1.0 / 255.0); if (height >= 0.9) { c[0] = color[0][0]; c[1] = color[0][1]; c[2] = color[0][2]; return; } if ((height < 0.9) && (height >= 0.7)) { fact = (height - 0.7) * 5.0; c[0] = fact * color[0][0] + (1.0 - fact) * color[1][0]; c[1] = fact * color[0][1] + (1.0 - fact) * color[1][1]; c[2] = fact * color[0][2] + (1.0 - fact) * color[1][2]; return; } if ((height < 0.7) && (height >= 0.6)) { fact = (height - 0.6) * 10.0; c[0] = fact * color[1][0] + (1.0 - fact) * color[2][0]; c[1] = fact * color[1][1] + (1.0 - fact) * color[2][1]; c[2] = fact * color[1][2] + (1.0 - fact) * color[2][2]; return; } if ((height < 0.6) && (height >= 0.5)) { fact = (height - 0.5) * 10.0; c[0] = fact * color[2][0] + (1.0 - fact) * color[3][0]; c[1] = fact * color[2][1] + (1.0 - fact) * color[3][1]; c[2] = fact * color[2][2] + (1.0 - fact) * color[3][2]; return; } c[0] = color[3][0]; c[1] = color[3][1]; c[2] = color[3][2]; } static void loadpic(void) { GLubyte bufferter[256 * 256], terrainpic[256 * 256]; FILE *FilePic; int i, tmp; GLenum gluerr; if ((FilePic = fopen("terrain.dat", "r")) == NULL) { fprintf(stderr, "Error loading terrain.dat\n"); exit(-1); } fread(bufferter, 256 * 256, 1, FilePic); fclose(FilePic); for (i = 0; i < (256 * 256); i++) { terrain[i] = (bufferter[i] * (heightMnt / 255.0f)); calccolor((GLfloat) bufferter[i], terraincolor[i]); tmp = (((int) bufferter[i]) + 96); terrainpic[i] = (tmp > 255) ? 255 : tmp; } glPixelStorei(GL_UNPACK_ALIGNMENT, 1); if ((gluerr = gluBuild2DMipmaps(GL_TEXTURE_2D, 1, 256, 256, GL_LUMINANCE, GL_UNSIGNED_BYTE, (GLvoid *) (&terrainpic[0])))) { fprintf(stderr, "GLULib%s\n", (char *) gluErrorString(gluerr)); exit(-1); } glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE); glEnable(GL_TEXTURE_2D); } static void init(void) { float fogcolor[4] = { 0.6, 0.7, 0.7, 1.0 }; glClearColor(fogcolor[0], fogcolor[1], fogcolor[2], fogcolor[3]); glClearDepth(1.0); glDepthFunc(GL_LEQUAL); glShadeModel(GL_SMOOTH); glEnable(GL_DEPTH_TEST); glEnable(GL_CULL_FACE); glDisable(GL_BLEND); glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); glEnable(GL_FOG); glFogi(GL_FOG_MODE, GL_EXP2); glFogfv(GL_FOG_COLOR, fogcolor); glFogf(GL_FOG_DENSITY, 0.0007); #ifdef FX glHint(GL_FOG_HINT, GL_NICEST); #endif reshape(scrwidth, scrheight); } int main(int ac, char **av) { glutInitWindowPosition(0, 0); glutInitWindowSize(WIDTH, HEIGHT); glutInit(&ac, av); glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE); if (!(win = glutCreateWindow("Terrain"))) { fprintf(stderr, "Error, couldn't open window\n"); return -1; } ModZMnt = 0.0f; loadpic(); init(); #ifndef FX glDisable(GL_TEXTURE_2D); usetex = 0; #endif glutReshapeFunc(reshape); glutDisplayFunc(drawscene); glutKeyboardFunc(key); glutSpecialFunc(special); glutIdleFunc(drawscene); glutMainLoop(); return 0; }