/***********************************************************************/ /***********************************************************************/ /* FreeVR OpenGL tutorial example 6: ex6_text.c */ /* FreeVR OpenGL tutorial example 7: ex7_pointer.c */ /* Last tested with: FreeVR version 0.6a */ /* Last tested with: FreeVR version 0.6a */ /* Last Modified: January 11, 2007 */ /* Last Modified: January 29, 2007 */ /* URL: http://freevr.org */ /* URL: http://freevr.org */ /***********************************************************************/ /***********************************************************************/ /* This example code demonstrates a VR application program that */ /* This example code demonstrates a VR application program that */ /* reports some of the internal world data textually via a very */ /* renders a pointer emanating from the wand. Everything else is */ /* simple 2D/raster font. (We'll do 3D text in a later example.) */ /* the same. */ /* */ /* */ /* */ /* */ /* The new features of this example include: */ /* The new features of this example include: */ /* - FreeVR Library functions, variables, and macros: */ /* - FreeVR Library functions, variables, and macros: */ /* * type vrRenderInfo */ /* * vrRenderTransform6sensor(rendinfo, ) */ /* * vrRenderText(rendinfo, ) */ /* - drawing a pointer emanating from the wand */ /* */ /* - uses a few more OpenGL calls */ /* - more advanced structure to the world-database */ /* */ /* */ /* Considerations: */ /* Considerations: */ /* - This is our first exposure to the vrRenderInfo type. But we */ /* will be using it in most of the rest of the examples. For */ /* the most part, the application programmer does not need to */ /* worry about the details of this type & renderer argument. */ /* It can best be thought of as simply a conduit through which */ /* internal VR state information can be passed from the */ /* overarching render loop process to VR rendering operations */ /* that require this external state knowledge to work properly. */ /* - Textual output is often an important means of communicating */ /* with the user. Certainly not every VR application requires */ /* the ability to put text about the state of the world in front */ /* of the user. However, it is always a useful feature to have */ /* when debugging a VR application (since the user/tester will */ /* generally not be sitting at the terminal to see printf-style */ /* messages). */ /* - 2D raster (aka bitmap) text is generally less useful in a */ /* virtual reality experience, because the bitmap is a fixed */ /* size (number of pixels), and will be rendered the same no */ /* matter how close the user gets to it. The best way to */ /* overcome this shortcoming is to always place the text at a */ /* location where this won't be noticed by the user. In the */ /* case of a CAVE-like environment, this means placing the text */ /* to be located on the plane of one of the screens. For a */ /* head-based system, the text should be on a head-up type */ /* widget that always remains a fixed distance from the user. */ /* */ /* */ /* This application uses the files: */ /* This application uses the files: */ /* - shapes.c (Bill Sherman's simple OpenGL shapes) */ /* - shapes.c (Bill Sherman's simple OpenGL shapes) */ /* */ /* */ /* Copyright 2010, William R. Sherman, All Rights Reserved. */ /* Copyright 2010, William R. Sherman, All Rights Reserved. */ /* In particular, the right to republish this file in whole or in */ /* In particular, the right to republish this file in whole or in */ /* part, in any form (including electronic forms) is prohibited */ /* part, in any form (including electronic forms) is prohibited */ /* without written consent of the copyright holder. */ /* without written consent of the copyright holder. */ /***********************************************************************/ /***********************************************************************/ #include <stdio.h> /* needed for printf(), etc. */ #include <stdio.h> /* needed for printf(), etc. */ #include <stdlib.h> /* needed for exit() */ #include <stdlib.h> /* needed for exit() */ #include <signal.h> /* needed for signal() and its arguments */ #include <signal.h> /* needed for signal() and its arguments */ #include <unistd.h> /* not sure why/whether this is needed */ #include <unistd.h> /* not sure why/whether this is needed */ #include <math.h> /* needed for sin(), cos(), fabs() & copysign() */ #include <math.h> /* needed for sin(), cos(), fabs() & copysign() */ #include <GL/gl.h> /* needed for all OpenGL functions & values */ #include <GL/gl.h> /* needed for all OpenGL functions & values */ #include "freevr.h" /* needed for FreeVR functions & values */ #include "freevr.h" /* needed for FreeVR functions & values */ #define WAND_SENSOR 1 /* TODO: this should really be based on the c /* Define a structure for information about each individual object. */ typedef struct { float x, y, z; /* location o GLubyte color[3]; /* color of t enum { cube,pyramid,ud_pyramid }shape; /* shape of t } ObjectType; /* Define a structure for holding a database of the virtual world. */ /* Define a structure for holding a database of the virtual world. */ typedef struct { typedef struct { float obj1_x, obj1_y, obj1_z; /* location o int number_of_objects; /* number of float obj2_x, obj2_y, obj2_z; /* location o ObjectType object[3]; /* array of o float obj3_x, obj3_y, obj3_z; /* location o } WorldDataType; } WorldDataType; /**************************************************************************** /**************************************************************************** /* These function declarations are very important -- they will be used as arg /* These function declarations are very important -- they will be used as arg void exit_application(int signal); /* cleanly close down operati void exit_application(int signal); /* cleanly close down operati void init_gfx(void); /* initialize the graphics void init_gfx(void); /* initialize the graphics void draw_world(WorldDataType *wd, vrRenderInfo *rendinfo); /* render the void draw_world(WorldDataType *wd, vrRenderInfo *rendinfo); /* render the void init_world(WorldDataType *wd); /* initialize the world param void init_world(WorldDataType *wd); /* initialize the world param void update_world(WorldDataType *wd); /* perform the world simulati void update_world(WorldDataType *wd); /* perform the world simulati /***********************************************************************/ /***********************************************************************/ main(int argc, char* argv[]) main(int argc, char* argv[]) { { WorldDataType *wd; WorldDataType *wd; /**********************************/ /**********************************/ /*** initialize FreeVR routines ***/ /*** initialize FreeVR routines ***/ /**********************************/ /**********************************/ signal(SIGINT, SIG_IGN); signal(SIGINT, SIG_IGN); vrConfigure(&argc, argv, NULL); /* allow CLAs to affect confi vrConfigure(&argc, argv, NULL); /* allow CLAs to affect confi vrStart(); vrStart(); signal(SIGINT, exit_application); signal(SIGINT, exit_application); /********************/ /********************/ /* create the world */ /* create the world */ wd = (WorldDataType *)vrShmemAlloc0(sizeof(WorldDataType)); wd = (WorldDataType *)vrShmemAlloc0(sizeof(WorldDataType)); init_world(wd); init_world(wd); /***************************************/ /***************************************/ /* set up the FreeVR library functions */ /* set up the FreeVR library functions */ vrFunctionSetCallback(VRFUNC_DISPLAY_INIT, vrCallbackCreate(init_gfx, vrFunctionSetCallback(VRFUNC_DISPLAY_INIT, vrCallbackCreate(init_gfx, vrFunctionSetCallback(VRFUNC_DISPLAY, vrCallbackCreate(draw_world, 1, vrFunctionSetCallback(VRFUNC_DISPLAY, vrCallbackCreate(draw_world, 1, /********************************************************/ /********************************************************/ /* define the application name, authors, controls, etc. */ /* define the application name, authors, controls, etc. */ vrSystemSetName("FreeVR tutorial: example 6 -- simple text"); vrSystemSetName("FreeVR tutorial: example 7 -- pointer"); vrSystemSetAuthors("Bill Sherman"); vrSystemSetAuthors("Bill Sherman"); vrSystemSetExtraInfo("An example to show basic 2D text rendering"); vrSystemSetExtraInfo("An example to show a pointer attached to the wa vrSystemSetStatusDescription("Application running fine"); vrSystemSetStatusDescription("Application running fine"); vrInputSet2switchDescription(0, "Terminate the application"); vrInputSet2switchDescription(0, "Terminate the application"); vrInputSet2switchDescription(1, "Raise the green pyramid"); vrInputSet2switchDescription(1, "Raise the green pyramid"); vrInputSet2switchDescription(2, "Reset the green pyramid"); vrInputSet2switchDescription(2, "Reset the green pyramid"); vrInputSet2switchDescription(3, "Lower the green pyramid"); vrInputSet2switchDescription(3, "Lower the green pyramid"); vrInputSetValuatorDescription(0, "Move the green pyramid in the Z-pla vrInputSetValuatorDescription(0, "Move the green pyramid in the Z-pla vrInputSetValuatorDescription(1, "Move the green pyramid in the X-pla vrInputSetValuatorDescription(1, "Move the green pyramid in the X-pla vrInputSet6sensorDescription(WAND_SENSOR, "Move a long cyan pointer") /***************************/ /***************************/ /*** do world simulation ***/ /*** do world simulation ***/ /***************************/ /***************************/ /* run until terminate key is pressed (Escape by default) */ /* run until terminate key is pressed (Escape by default) */ while(!vrGet2switchValue(0)) { while(!vrGet2switchValue(0)) { vrFrame(); vrFrame(); update_world(wd); update_world(wd); } } /*********************/ /*********************/ /*** close up shop ***/ /*** close up shop ***/ /*********************/ /*********************/ exit_application(0); exit_application(0); } } /********************************************************************/ /********************************************************************/ /* exit_application(): clean up anything started by the application */ /* exit_application(): clean up anything started by the application */ /* (forked processes, open files, open sockets, etc.) */ /* (forked processes, open files, open sockets, etc.) */ /********************************************************************/ /********************************************************************/ void exit_application(int signal) void exit_application(int signal) { { vrExit(); vrExit(); exit(0); exit(0); } } /* ----------------8<-----------------8<-----------------8<----------------*/ /* ----------------8<-----------------8<-----------------8<----------------*/ /* In a non-example applicatation, the following would be a separate file. */ /* In a non-example applicatation, the following would be a separate file. */ /**********************************/ /**********************************/ /**********************************/ /**********************************/ /** The World Simulation section **/ /** The World Simulation section **/ /**********************************/ /**********************************/ /**********************************/ /**********************************/ /**************************************************************/ /**************************************************************/ /* init_world(): create the initial conditions of the dynamic */ /* init_world(): create the initial conditions of the dynamic */ /* simulation. */ /* simulation. */ /**************************************************************/ /**************************************************************/ void init_world(WorldDataType *wd) void init_world(WorldDataType *wd) { { /* initial location of object 1 - a blue cube */ int objnum = 0; wd->obj1_x = -2.0; wd->obj1_y = 5.0; wd->obj1_z = -5.0; /* initial location of object 2 - a red pyramid */ /* object 1 - a blue cube */ wd->obj2_x = 2.0; wd->object[objnum].shape = cube; wd->obj2_y = 5.0; wd->object[objnum].color[0] = 100; wd->obj2_z = -5.0; wd->object[objnum].color[1] = 100; wd->object[objnum].color[2] = 255; wd->object[objnum].x = -2.0; wd->object[objnum].y = 5.0; wd->object[objnum].z = -5.0; objnum++; /* initial location of object 3 - an upside-down green pyramid */ /* object 2 - a red pyramid */ wd->obj3_x = 0.0; wd->object[objnum].shape = pyramid; wd->obj3_y = 5.0; wd->object[objnum].color[0] = 255; wd->obj3_z = -5.0; wd->object[objnum].color[1] = 100; wd->object[objnum].color[2] = 100; wd->object[objnum].x = 2.0; wd->object[objnum].y = 5.0; wd->object[objnum].z = -5.0; objnum++; /* object 3 - an upside-down green pyramid */ wd->object[objnum].shape = ud_pyramid; wd->object[objnum].color[0] = 100; wd->object[objnum].color[1] = 255; wd->object[objnum].color[2] = 100; wd->object[objnum].x = 0.0; wd->object[objnum].y = 5.0; wd->object[objnum].z = -5.0; objnum++; wd->number_of_objects = objnum; } } /*********************************************************************/ /*********************************************************************/ /* update_world(): Basic world with simple interactions. */ /* update_world(): Basic world with simple interactions. */ /*********************************************************************/ /*********************************************************************/ void update_world(WorldDataType *wd) void update_world(WorldDataType *wd) { { #define JS_EPSILON 0.125 /* the dead-zone befo #define JS_EPSILON 0.125 /* the dead-zone befo #define MOVE_FACTOR 2.5 /* a movement scale f #define MOVE_FACTOR 2.5 /* a movement scale f static vrTime last_time = -1.0; /* initially set to a static vrTime last_time = -1.0; /* initially set to a vrTime sim_time = vrCurrentSimTime(); /* the current time o vrTime sim_time = vrCurrentSimTime(); /* the current time o double delta_time; /* time since last up double delta_time; /* time since last up double joy_x, joy_y; /* Joystick values */ double joy_x, joy_y; /* Joystick values */ /*****************************************************/ /*****************************************************/ /** Determine delta time from last simulation frame **/ /** Determine delta time from last simulation frame **/ /*****************************************************/ /*****************************************************/ if (last_time == -1.0) if (last_time == -1.0) delta_time = 0.0; delta_time = 0.0; else delta_time = sim_time - last_time; else delta_time = sim_time - last_time; last_time = sim_time; /* now that delta_tim last_time = sim_time; /* now that delta_tim /* skip the update if the delta isn't big enough */ /* skip the update if the delta isn't big enough */ if (delta_time <= 0.0) /* can also choose a non-zero epsilon */ if (delta_time <= 0.0) /* can also choose a non-zero epsilon */ return; return; /****************************************/ /****************************************/ /* Move the objects with constant speed */ /* Move the objects with constant speed */ /* object 1 travels in a horizontal circle at a fixed speed */ /* object 1 travels in a horizontal circle at a fixed speed */ wd->obj1_x = 3*sin(sim_time * 2.0); wd->object[0].x = 3*sin(sim_time * 2.0); wd->obj1_z = 3*cos(sim_time * 2.0) - 5.0; wd->object[0].z = 3*cos(sim_time * 2.0) - 5.0; /* object 2 travels in a verticle circle at a fixed speed */ /* object 2 travels in a verticle circle at a fixed speed */ wd->obj2_x = 3*cos(sim_time * 2.0); wd->object[1].x = 3*cos(sim_time * 2.0); wd->obj2_y = 3*sin(sim_time * 2.0) + 5.0; wd->object[1].y = 3*sin(sim_time * 2.0) + 5.0; /**************************/ /**************************/ /* User interface section */ /* User interface section */ /* the first button moves the object up, when initially pressed */ /* the first button moves the object up, when initially pressed */ if (vrGet2switchDelta(1) == 1) { if (vrGet2switchDelta(1) == 1) { wd->obj3_y += 1.0; wd->object[2].y += 1.0; } } /* the second button resets the object's location, when initially pre /* the second button resets the object's location, when initially pre if (vrGet2switchDelta(2) == 1) { if (vrGet2switchDelta(2) == 1) { wd->obj3_x = 0.0; wd->object[2].x = 0.0; wd->obj3_y = 5.0; wd->object[2].y = 5.0; wd->obj3_z = -5.0; wd->object[2].z = -5.0; } } /* the third button moves the object down, when initially pressed */ /* the third button moves the object down, when initially pressed */ if (vrGet2switchDelta(3) == 1) { if (vrGet2switchDelta(3) == 1) { wd->obj3_y -= 1.0; wd->object[2].y -= 1.0; } } /* store input values so they are consistent throughout update routin /* store input values so they are consistent throughout update routin joy_x = vrGetValuatorValue(0); joy_x = vrGetValuatorValue(0); joy_y = vrGetValuatorValue(1); joy_y = vrGetValuatorValue(1); /* now use those values to move the object */ /* now use those values to move the object */ if (fabs(joy_x) > JS_EPSILON) if (fabs(joy_x) > JS_EPSILON) wd->obj3_x += joy_x * delta_time * MOVE_FACTOR; wd->object[2].x += joy_x * delta_time * MOVE_FACTOR; if (fabs(joy_y) > JS_EPSILON) if (fabs(joy_y) > JS_EPSILON) wd->obj3_z -= (joy_y-copysign(JS_EPSILON,joy_y)) * delta_time wd->object[2].z -= (joy_y-copysign(JS_EPSILON,joy_y)) * delta /****************************************************/ /****************************************************/ /* yield to allow other processes access to the CPU */ /* yield to allow other processes access to the CPU */ vrSleep(0); vrSleep(0); } } /* ----------------8<-----------------8<-----------------8<----------------*/ /* ----------------8<-----------------8<-----------------8<----------------*/ /* In a non-example applicatation, the following would be a separate file. */ /* In a non-example applicatation, the following would be a separate file. */ /**************************/ /**************************/ /**************************/ /**************************/ /** The Graphics section **/ /** The Graphics section **/ /**************************/ /**************************/ /**************************/ /**************************/ /* functions from shapes.c */ /* functions from shapes.c */ void draw_cube(); void draw_cube(); void draw_pyramid(); void draw_pyramid(); void draw_cube_outline(); void draw_pyramid_outline(); /*********************************************************************/ /*********************************************************************/ /* init_gfx(): initialize general graphics properties (eg. lighting) */ /* init_gfx(): initialize general graphics properties (eg. lighting) */ /*********************************************************************/ /*********************************************************************/ void init_gfx(void) void init_gfx(void) { { GLfloat location_0[4] = { 0.0, 10.0, 10.0, 1.0 /* 0 = directional, 1 GLfloat location_0[4] = { 0.0, 10.0, 10.0, 1.0 /* 0 = directional, 1 ambient_0[4] = { 0.2, 0.2, 0.2, 1.0 }, ambient_0[4] = { 0.2, 0.2, 0.2, 1.0 }, diffuse_0[4] = { 0.8, 0.8, 0.8, 1.0 }, diffuse_0[4] = { 0.8, 0.8, 0.8, 1.0 }, specular_0[4] = { 0.2, 0.2, 0.2, 1.0 }; specular_0[4] = { 0.2, 0.2, 0.2, 1.0 }; /****************************************/ /****************************************/ /* set the render initialization values */ /* set the render initialization values */ glClearColor(0.0, 0.0, 0.0, 0.0); glClearColor(0.0, 0.0, 0.0, 0.0); glClearDepth(1.0); glClearDepth(1.0); /********************************************************/ /********************************************************/ /* set the polygon shading/lighting/material parameters */ /* set the polygon shading/lighting/material parameters */ glShadeModel(GL_SMOOTH); glShadeModel(GL_SMOOTH); glEnable(GL_LIGHTING); glEnable(GL_LIGHTING); glLightfv(GL_LIGHT0, GL_POSITION, location_0); glLightfv(GL_LIGHT0, GL_POSITION, location_0); glLightfv(GL_LIGHT0, GL_AMBIENT, ambient_0); glLightfv(GL_LIGHT0, GL_AMBIENT, ambient_0); glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuse_0); glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuse_0); glLightfv(GL_LIGHT0, GL_SPECULAR, specular_0); glLightfv(GL_LIGHT0, GL_SPECULAR, specular_0); glEnable(GL_LIGHT0); glEnable(GL_LIGHT0); /* These two lines cause the vertex colors to be used (otherwise all /* These two lines cause the vertex colors to be used (otherwise all glColorMaterial(GL_FRONT, GL_AMBIENT_AND_DIFFUSE); glColorMaterial(GL_FRONT, GL_AMBIENT_AND_DIFFUSE); glEnable(GL_COLOR_MATERIAL); glEnable(GL_COLOR_MATERIAL); glEnable(GL_NORMALIZE); /* this is required when calling glScalef() w glEnable(GL_NORMALIZE); /* this is required when calling glScalef() w /***************************/ /* set the line parameters */ glEnable(GL_LINE_SMOOTH); glLineWidth(2.0); } } /*************************************************************/ /*******************************************************************/ /* draw_world(): Render the three objects in the world. */ /* draw_world(): Now will render how ever many objects are in the */ /* Note that two of the objects (the blue cube, and red */ /* world data structure. The color, type (and maybe rotation) */ /* pyramid) get their locations from the world database */ /* are all now stored for each object, in addition to location. */ /*************************************************************/ /*******************************************************************/ void draw_world(WorldDataType *wd, vrRenderInfo *rendinfo) void draw_world(WorldDataType *wd, vrRenderInfo *rendinfo) { { static GLfloat location_0[4] = { 0.0, 10.0, 0.0, 1.0 /* 0 = directio static GLfloat location_0[4] = { 0.0, 10.0, 0.0, 1.0 /* 0 = directio static char msg[128]; /* memory for text st static char msg[128]; /* memory for text st int objnum; /* object counter */ /**************************************/ /**************************************/ /* clear the screen -- very important */ /* clear the screen -- very important */ glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); /******************************************************************** /******************************************************************** /* update the light's location -- must be done independently for each /* update the light's location -- must be done independently for each glLightfv(GL_LIGHT0, GL_POSITION, location_0); glLightfv(GL_LIGHT0, GL_POSITION, location_0); /************************/ /******************************************/ /* draw all the objects */ /* draw a pointer emanating from the wand */ /* a blue cube */ glColor3ub(100, 100, 255); glPushMatrix(); glPushMatrix(); glTranslatef(wd->obj1_x, wd->obj1_y, wd->obj1_z); glColor3ub(100, 255, 255); /* cyan */ draw_cube(); vrRenderTransform6sensor(rendinfo, WAND_SENSOR); glRotatef(-90.0, 1.0, 0.0, 0.0); glScalef(0.1, 1.5, 0.1); glTranslatef(0.0, 1.0, 0.0); draw_pyramid_outline(); glPopMatrix(); glPopMatrix(); /* a red pyramid */ /************************/ glColor3ub(255, 100, 100); /* draw all the objects */ glPushMatrix(); glTranslatef(wd->obj2_x, wd->obj2_y, wd->obj2_z); draw_pyramid(); glPopMatrix(); /* the green upside-down pyramid */ for (objnum = 0; objnum < wd->number_of_objects; objnum++) { glColor3ub(100, 255, 100); glPushMatrix(); glColor3ubv(wd->object[objnum].color); glTranslatef(wd->obj3_x, wd->obj3_y, wd->obj3_z); glPushMatrix(); glScalef(1.0, -1.0, 1.0); glTranslatef(wd->object[objnum].x, wd->object[objnum] draw_pyramid(); switch (wd->object[objnum].shape) { glPopMatrix(); case cube: draw_cube(); break; case pyramid: draw_pyramid(); break; case ud_pyramid: glScalef(1.0, -1.0, 1.0); draw_pyramid(); break; } glPopMatrix(); } /*************************************************/ /*************************************************/ /* draw text indicating the location of object 3 */ /* draw text indicating the location of object 3 */ sprintf(msg, "Green pyramid is at %.2f %.2f %.2f", wd->obj3_x, wd->ob sprintf(msg, "Green pyramid is at %.2f %.2f %.2f", wd->object[2].x, w glDisable(GL_LIGHTING); /* make the text bright regardless of glDisable(GL_LIGHTING); /* make the text bright regardless of glColor3ub(255, 255, 255); /* white */ glColor3ub(255, 255, 255); /* white */ glPushMatrix(); glPushMatrix(); glTranslatef(-4.0, 7.0, -5.0); /* on the front screen */ glTranslatef(-4.0, 7.0, -5.0); /* on the front screen */ glRasterPos3f(0.0, 0.0, 0.0); /* go to the 3D location */ glRasterPos3f(0.0, 0.0, 0.0); /* go to the 3D location */ vrRenderText(rendinfo, msg); vrRenderText(rendinfo, msg); glPopMatrix(); glPopMatrix(); glEnable(GL_LIGHTING); glEnable(GL_LIGHTING); } }