/* get_camera_matrix_f: * Floating point version of get_camera_matrix(). */ void get_camera_matrix_f(MATRIX_f *m, float x, float y, float z, float xfront, float yfront, float zfront, float xup, float yup, float zup, float fov, float aspect) { MATRIX_f camera, scale; float xside, yside, zside, width, d; ASSERT(m); /* make 'in-front' into a unit vector, and negate it */ normalize_vector_f(&xfront, &yfront, &zfront); xfront = -xfront; yfront = -yfront; zfront = -zfront; /* make sure 'up' is at right angles to 'in-front', and normalize */ d = dot_product_f(xup, yup, zup, xfront, yfront, zfront); xup -= d * xfront; yup -= d * yfront; zup -= d * zfront; normalize_vector_f(&xup, &yup, &zup); /* calculate the 'sideways' vector */ cross_product_f(xup, yup, zup, xfront, yfront, zfront, &xside, &yside, &zside); /* set matrix rotation parameters */ camera.v[0][0] = xside; camera.v[0][1] = yside; camera.v[0][2] = zside; camera.v[1][0] = xup; camera.v[1][1] = yup; camera.v[1][2] = zup; camera.v[2][0] = xfront; camera.v[2][1] = yfront; camera.v[2][2] = zfront; /* set matrix translation parameters */ camera.t[0] = -(x*xside + y*yside + z*zside); camera.t[1] = -(x*xup + y*yup + z*zup); camera.t[2] = -(x*xfront + y*yfront + z*zfront); /* construct a scaling matrix to deal with aspect ratio and FOV */ width = floattan(64.0 - fov/2); get_scaling_matrix_f(&scale, width, -aspect*width, -1.0); /* combine the camera and scaling matrices */ matrix_mul_f(&camera, &scale, m); }
/* get_vector_rotation_matrix_f: * Floating point version of get_vector_rotation_matrix(). */ void get_vector_rotation_matrix_f(MATRIX_f *m, float x, float y, float z, float a) { float c, s, cc; ASSERT(m); FLOATSINCOS(a, s, c); cc = 1 - c; normalize_vector_f(&x, &y, &z); m->v[0][0] = (cc * x * x) + c; m->v[0][1] = (cc * x * y) + (z * s); m->v[0][2] = (cc * x * z) - (y * s); m->v[1][0] = (cc * x * y) - (z * s); m->v[1][1] = (cc * y * y) + c; m->v[1][2] = (cc * z * y) + (x * s); m->v[2][0] = (cc * x * z) + (y * s); m->v[2][1] = (cc * y * z) - (x * s); m->v[2][2] = (cc * z * z) + c; m->t[0] = m->t[1] = m->t[2] = 0; }
int main() { /* Setup Allegro/AllegroGL */ if (allegro_init()) return 1; if (install_allegro_gl()) return 1; if (install_keyboard() < 0) { allegro_message("Unable to install keyboard\n"); return 1; } if (install_mouse() == -1) { allegro_message("Unable to install mouse\n"); return 1; } if (install_timer() < 0) { allegro_message("Unable to install timers\n"); return 1; } /* lock timer */ LOCK_VARIABLE(rotation_counter); LOCK_FUNCTION(rotation_counter_handler); /* set desktop resolution */ DESKTOP_W = GetSystemMetrics(SM_CXVIRTUALSCREEN); DESKTOP_H = GetSystemMetrics(SM_CYVIRTUALSCREEN); /* get monitor resolution/count */ int monitor_count; MONITOR *monitors = get_monitors(&monitor_count); /* generate point data */ PLACE places[POINT_COUNT]; int c; for (c = 1; c < POINT_COUNT - 1; c++) { places[c].x = sin((M_PI * (GLfloat)c) / 10.0f) * 200.0f; places[c].y = cos((M_PI * (GLfloat)c) / 10.0f) * 200.0f; } places[0].x = 0.01; places[0].y = 200.0f; places[POINT_COUNT - 1].x = 0.01; places[POINT_COUNT - 1].y = -200.0f; /* setup display */ allegro_gl_set(AGL_Z_DEPTH, 8); allegro_gl_set(AGL_COLOR_DEPTH, 16); allegro_gl_set(AGL_SUGGEST, AGL_Z_DEPTH | AGL_COLOR_DEPTH); glDepthFunc(GL_LEQUAL); if (set_gfx_mode(GFX_OPENGL_WINDOWED_BORDERLESS, DESKTOP_W, DESKTOP_H, 0, 0)) { set_gfx_mode(GFX_TEXT, 0, 0, 0, 0); allegro_message("Unable to set graphic mode\n%s\n", allegro_error); return 1; } /* move window so it covers the desktop */ position_window(0, 0); /* fake information to use if only 1 monitor */ MONITOR fake = {0, 512, 512, 512}; /* setup lighting model */ glShadeModel(GL_FLAT); glEnable(GL_LIGHT0); glEnable(GL_COLOR_MATERIAL); GLfloat light_position[] = { 1.0, 1.0, 1.0, 0.0 }; glLightfv(GL_LIGHT0, GL_POSITION, light_position); GLfloat ambient[] = { 0.1f, 0.1f, 0.1f }; glLightfv(GL_LIGHT0, GL_AMBIENT, ambient); int selected = -1; /* the point currently being moved */ GLfloat rotation[3] = {0, 0, 0}; /* the rotation of the mesh */ install_int(rotation_counter_handler, 20); /* install the rotation handler */ /* enter main program loop */ while(!key[KEY_ESC]) { while (rotation_counter > 0) { /* rotate the mesh */ rotation[0] += M_PI / 24.0f; rotation[1] += M_PI / 16.0f; rotation[2] += M_PI / 8.0f; rotation_counter--; } /* clear the buffers */ glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); /* process monitor 0 */ MONITOR *m = &monitors[0]; /* adjust mouse so its relative to the monitor */ int mx = (mouse_x - m->x) - (m->w / 2); int my = (mouse_y - m->y) - (m->h / 2); /* if the left mouse is pushed, find a close point */ if (mouse_b & 1) { if (selected == -1) { GLfloat distance = 10; for (c = 0; c < POINT_COUNT; c++) { GLfloat dx = mx - places[c].x; GLfloat dy = my - places[c].y; GLfloat d = sqrt(dx * dx + dy * dy); if (d < distance) { distance = d; selected = c; } } } } else selected = -1; /* move selected point */ if (selected >= 0) { places[selected].x = mx; places[selected].y = my; } /* center the viewport on monitor */ glViewport(m->x, DESKTOP_H - m->h - m->y, m->w, m->h); /* setup viewport projection */ glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluOrtho2D(-m->w / 2, m->w / 2, m->h / 2, -m->h / 2); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); /* draw points */ glColor3ub(0, 255, 0); glBegin(GL_LINE_STRIP); for (c = 0; c < POINT_COUNT; c++) { glVertex2f(places[c].x, places[c].y); } glEnd(); glColor3ub(255, 255, 255); for (c = 0; c < POINT_COUNT; c++) { draw_square(places[c].x, places[c].y, 10); } /* draw vertical line */ glBegin(GL_LINE_STRIP); glVertex2f(0.0f, -m->h); glVertex2f(0.0f, m->h); glEnd(); /* draw the mouse */ glColor3ub(255, 255, 255); draw_square(mx, my, 20); /* process viewport 1 */ /* select second monitor */ if (monitor_count > 1) { /* if 2nd monitor exists use it */ m = &monitors[1]; } else { /* use fake monitor */ m = &fake; } /* adjust mouse so its relative to the monitor*/ mx = (mouse_x - m->x) - (m->w / 2); my = (mouse_y - m->y) - (m->h / 2); /* center the viewport on the monitor*/ glViewport(m->x, DESKTOP_H - m->h - m->y, m->w, m->h); /* setup viewport projection */ glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluPerspective(45.0f, (float)m->w / (float)m->h, 0.1f, 2000.0f); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); /* turn on lighting and depth testing */ glEnable(GL_LIGHTING); glEnable(GL_DEPTH_TEST); /* move mesh so its visible */ glTranslatef(0.0f, 0.0f, -1000.0f); /* rotate mesh */ glRotatef(rotation[0], 1.0f, 0.0f, 0.0f); glRotatef(rotation[1], 0.0f, 1.0f, 0.0f); glRotatef(rotation[2], 0.0f, 0.0f, 1.0f); GLfloat p1[3] = {0, 0, 0}; GLfloat p2[3] = {0, 0, 0}; GLfloat p3[3] = {0, 0, 0}; GLfloat p4[3] = {0, 0, 0}; GLfloat vec1[3]; GLfloat vec2[3]; GLfloat normal[3]; /* draw mesh to screen */ glColor3ub(0, 255, 0); for (c = 0; c < (POINT_COUNT - 1); c++) { GLfloat a1 = 0; GLfloat a2 = M_PI / 16.0f; GLfloat d1 = places[c].x; GLfloat d2 = places[c + 1].x; p1[0] = sin(a1) * d1; p1[1] = places[c].y; p1[2] = cos(a1) * d1; p2[0] = sin(a2) * d1; p2[1] = places[c].y; p2[2] = cos(a2) * d1; p3[0] = sin(a2) * d2; p3[1] = places[c + 1].y; p3[2] = cos(a2) * d2; p4[0] = sin(a1) * d2; p4[1] = places[c + 1].y; p4[2] = cos(a1) * d2; buildVector(vec1, p1, p2); buildVector(vec2, p1, p4); cross_product_f(vec2[0], vec2[1], vec2[2], vec1[0], vec1[1], vec1[2], &normal[0], &normal[1], &normal[2]); normalize_vector_f(&normal[0], &normal[1], &normal[2]); glBegin(GL_QUAD_STRIP); glNormal3fv(normal); glVertex3fv(p1); glVertex3fv(p4); int s = 0; for (s = 1; s < 32; s++) { a2 = (M_PI * (GLfloat)(s + 1)) / 16.0f; d1 = places[c].x; d2 = places[c + 1].x; copyPoint(p1, p2); copyPoint(p4, p3); p2[0] = sin(a2) * d1; p2[1] = places[c].y; p2[2] = cos(a2) * d1; p3[0] = sin(a2) * d2; p3[1] = places[c + 1].y; p3[2] = cos(a2) * d2; buildVector(vec1, p1, p2); buildVector(vec2, p1, p4); cross_product_f(vec2[0], vec2[1], vec2[2], vec1[0], vec1[1], vec1[2], &normal[0], &normal[1], &normal[2]); normalize_vector_f(&normal[0], &normal[1], &normal[2]); glNormal3fv(normal); glVertex3fv(p2); glVertex3fv(p3); } glEnd(); } /* turn off lighting and depth testing */ glDisable(GL_DEPTH_TEST); glDisable(GL_LIGHTING); /* if not using the fake monitor */ if (m != &fake) { /* setup viewport projection */ glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluOrtho2D(-m->w / 2, m->w / 2, m->h / 2, -m->h / 2); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); /* draw the mouse */ glColor3ub(255, 255, 255); draw_square(mx, my, 20); } /* flip the contents to the screen */ allegro_gl_flip(); } free(monitors); return 0; }