1 // ---------------------------------------------------------------------------
2 //
3 // @file TwSimpleGLUT.c
4 // @brief A simple example that uses AntTweakBar with OpenGL and GLUT.
5 //
6 // AntTweakBar: http://anttweakbar.sourceforge.net/doc
7 // OpenGL: http://www.opengl.org
8 // GLUT: http://opengl.org/resources/libraries/glut
9 //
10 // @author Philippe Decaudin
11 // @date 2006/05/20
12 //
13 // ---------------------------------------------------------------------------
14
15
16 #include <AntTweakBar.h>
17
18 #include <stdlib.h>
19 #include <stdio.h>
20 #include <math.h>
21
22 #if defined(_WIN32) || defined(_WIN64)
23 // MiniGLUT.h is provided to avoid the need of having GLUT installed to
24 // recompile this example. Do not use it in your own programs, better
25 // install and use the actual GLUT library SDK.
26 # define USE_MINI_GLUT
27 #endif
28
29 #if defined(USE_MINI_GLUT)
30 # include "../src/MiniGLUT.h"
31 #elif defined(_MACOSX)
32 # include <GLUT/glut.h>
33 #else
34 # include <GL/glut.h>
35 #endif
36
37 // This example displays one of the following shapes
38 typedef enum { SHAPE_TEAPOT=1, SHAPE_TORUS, SHAPE_CONE } Shape;
39 #define NUM_SHAPES 3
40 Shape g_CurrentShape = SHAPE_TORUS;
41 // Shapes scale
42 float g_Zoom = 1.0f;
43 // Shape orientation (stored as a quaternion)
44 float g_Rotation[] = { 0.0f, 0.0f, 0.0f, 1.0f };
45 // Auto rotate
46 int g_AutoRotate = 0;
47 int g_RotateTime = 0;
48 float g_RotateStart[] = { 0.0f, 0.0f, 0.0f, 1.0f };
49 // Shapes material
50 float g_MatAmbient[] = { 0.5f, 0.0f, 0.0f, 1.0f };
51 float g_MatDiffuse[] = { 1.0f, 1.0f, 0.0f, 1.0f };
52 // Light parameter
53 float g_LightMultiplier = 1.0f;
54 float g_LightDirection[] = { -0.57735f, -0.57735f, -0.57735f };
55
56
57 // Routine to set a quaternion from a rotation axis and angle
58 // ( input axis = float[3] angle = float output: quat = float[4] )
SetQuaternionFromAxisAngle(const float * axis,float angle,float * quat)59 void SetQuaternionFromAxisAngle(const float *axis, float angle, float *quat)
60 {
61 float sina2, norm;
62 sina2 = (float)sin(0.5f * angle);
63 norm = (float)sqrt(axis[0]*axis[0] + axis[1]*axis[1] + axis[2]*axis[2]);
64 quat[0] = sina2 * axis[0] / norm;
65 quat[1] = sina2 * axis[1] / norm;
66 quat[2] = sina2 * axis[2] / norm;
67 quat[3] = (float)cos(0.5f * angle);
68 }
69
70
71 // Routine to convert a quaternion to a 4x4 matrix
72 // ( input: quat = float[4] output: mat = float[4*4] )
ConvertQuaternionToMatrix(const float * quat,float * mat)73 void ConvertQuaternionToMatrix(const float *quat, float *mat)
74 {
75 float yy2 = 2.0f * quat[1] * quat[1];
76 float xy2 = 2.0f * quat[0] * quat[1];
77 float xz2 = 2.0f * quat[0] * quat[2];
78 float yz2 = 2.0f * quat[1] * quat[2];
79 float zz2 = 2.0f * quat[2] * quat[2];
80 float wz2 = 2.0f * quat[3] * quat[2];
81 float wy2 = 2.0f * quat[3] * quat[1];
82 float wx2 = 2.0f * quat[3] * quat[0];
83 float xx2 = 2.0f * quat[0] * quat[0];
84 mat[0*4+0] = - yy2 - zz2 + 1.0f;
85 mat[0*4+1] = xy2 + wz2;
86 mat[0*4+2] = xz2 - wy2;
87 mat[0*4+3] = 0;
88 mat[1*4+0] = xy2 - wz2;
89 mat[1*4+1] = - xx2 - zz2 + 1.0f;
90 mat[1*4+2] = yz2 + wx2;
91 mat[1*4+3] = 0;
92 mat[2*4+0] = xz2 + wy2;
93 mat[2*4+1] = yz2 - wx2;
94 mat[2*4+2] = - xx2 - yy2 + 1.0f;
95 mat[2*4+3] = 0;
96 mat[3*4+0] = mat[3*4+1] = mat[3*4+2] = 0;
97 mat[3*4+3] = 1;
98 }
99
100
101 // Routine to multiply 2 quaternions (ie, compose rotations)
102 // ( input q1 = float[4] q2 = float[4] output: qout = float[4] )
MultiplyQuaternions(const float * q1,const float * q2,float * qout)103 void MultiplyQuaternions(const float *q1, const float *q2, float *qout)
104 {
105 float qr[4];
106 qr[0] = q1[3]*q2[0] + q1[0]*q2[3] + q1[1]*q2[2] - q1[2]*q2[1];
107 qr[1] = q1[3]*q2[1] + q1[1]*q2[3] + q1[2]*q2[0] - q1[0]*q2[2];
108 qr[2] = q1[3]*q2[2] + q1[2]*q2[3] + q1[0]*q2[1] - q1[1]*q2[0];
109 qr[3] = q1[3]*q2[3] - (q1[0]*q2[0] + q1[1]*q2[1] + q1[2]*q2[2]);
110 qout[0] = qr[0]; qout[1] = qr[1]; qout[2] = qr[2]; qout[3] = qr[3];
111 }
112
113
114 // Return elapsed time in milliseconds
GetTimeMs()115 int GetTimeMs()
116 {
117 #if !defined(_WIN32)
118 return glutGet(GLUT_ELAPSED_TIME);
119 #else
120 // glutGet(GLUT_ELAPSED_TIME) seems buggy on Windows
121 return (int)GetTickCount();
122 #endif
123 }
124
125
126 // Callback function called by GLUT to render screen
Display(void)127 void Display(void)
128 {
129 float v[4]; // will be used to set light parameters
130 float mat[4*4]; // rotation matrix
131
132 // Clear frame buffer
133 glClearColor(0, 0, 0, 1);
134 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
135
136 glEnable(GL_DEPTH_TEST);
137 glDisable(GL_CULL_FACE);
138 glEnable(GL_NORMALIZE);
139
140 // Set light
141 glEnable(GL_LIGHTING);
142 glEnable(GL_LIGHT0);
143 v[0] = v[1] = v[2] = g_LightMultiplier*0.4f; v[3] = 1.0f;
144 glLightfv(GL_LIGHT0, GL_AMBIENT, v);
145 v[0] = v[1] = v[2] = g_LightMultiplier*0.8f; v[3] = 1.0f;
146 glLightfv(GL_LIGHT0, GL_DIFFUSE, v);
147 v[0] = -g_LightDirection[0]; v[1] = -g_LightDirection[1]; v[2] = -g_LightDirection[2]; v[3] = 0.0f;
148 glLightfv(GL_LIGHT0, GL_POSITION, v);
149
150 // Set material
151 glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT, g_MatAmbient);
152 glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, g_MatDiffuse);
153
154 // Rotate and draw shape
155 glPushMatrix();
156 glTranslatef(0.5f, -0.3f, 0.0f);
157 if( g_AutoRotate )
158 {
159 float axis[3] = { 0, 1, 0 };
160 float angle = (float)(GetTimeMs()-g_RotateTime)/1000.0f;
161 float quat[4];
162 SetQuaternionFromAxisAngle(axis, angle, quat);
163 MultiplyQuaternions(g_RotateStart, quat, g_Rotation);
164 }
165 ConvertQuaternionToMatrix(g_Rotation, mat);
166 glMultMatrixf(mat);
167 glScalef(g_Zoom, g_Zoom, g_Zoom);
168 glCallList(g_CurrentShape);
169 glPopMatrix();
170
171 // Draw tweak bars
172 TwDraw();
173
174 // Present frame buffer
175 glutSwapBuffers();
176
177 // Recall Display at next frame
178 glutPostRedisplay();
179 }
180
181
182 // Callback function called by GLUT when window size changes
Reshape(int width,int height)183 void Reshape(int width, int height)
184 {
185 // Set OpenGL viewport and camera
186 glViewport(0, 0, width, height);
187 glMatrixMode(GL_PROJECTION);
188 glLoadIdentity();
189 gluPerspective(40, (double)width/height, 1, 10);
190 glMatrixMode(GL_MODELVIEW);
191 glLoadIdentity();
192 gluLookAt(0,0,5, 0,0,0, 0,1,0);
193 glTranslatef(0, 0.6f, -1);
194
195 // Send the new window size to AntTweakBar
196 TwWindowSize(width, height);
197 }
198
199
200 // Function called at exit
Terminate(void)201 void Terminate(void)
202 {
203 glDeleteLists(SHAPE_TEAPOT, NUM_SHAPES);
204
205 TwTerminate();
206 }
207
208
209 // Callback function called when the 'AutoRotate' variable value of the tweak bar has changed
SetAutoRotateCB(const void * value,void * clientData)210 void TW_CALL SetAutoRotateCB(const void *value, void *clientData)
211 {
212 (void)clientData; // unused
213
214 g_AutoRotate = *(const int *)value; // copy value to g_AutoRotate
215 if( g_AutoRotate!=0 )
216 {
217 // init rotation
218 g_RotateTime = GetTimeMs();
219 g_RotateStart[0] = g_Rotation[0];
220 g_RotateStart[1] = g_Rotation[1];
221 g_RotateStart[2] = g_Rotation[2];
222 g_RotateStart[3] = g_Rotation[3];
223
224 // make Rotation variable read-only
225 TwDefine(" TweakBar/ObjRotation readonly ");
226 }
227 else
228 // make Rotation variable read-write
229 TwDefine(" TweakBar/ObjRotation readwrite ");
230 }
231
232
233 // Callback function called by the tweak bar to get the 'AutoRotate' value
GetAutoRotateCB(void * value,void * clientData)234 void TW_CALL GetAutoRotateCB(void *value, void *clientData)
235 {
236 (void)clientData; // unused
237 *(int *)value = g_AutoRotate; // copy g_AutoRotate to value
238 }
239
240
241 // Main
main(int argc,char * argv[])242 int main(int argc, char *argv[])
243 {
244 TwBar *bar; // Pointer to the tweak bar
245 float axis[] = { 0.7f, 0.7f, 0.0f }; // initial model rotation
246 float angle = 0.8f;
247
248 // Initialize GLUT
249 glutInit(&argc, argv);
250 glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
251 glutInitWindowSize(640, 480);
252 glutCreateWindow("AntTweakBar simple example using GLUT");
253 glutCreateMenu(NULL);
254
255 // Set GLUT callbacks
256 glutDisplayFunc(Display);
257 glutReshapeFunc(Reshape);
258 atexit(Terminate); // Called after glutMainLoop ends
259
260 // Initialize AntTweakBar
261 TwInit(TW_OPENGL, NULL);
262
263 // Set GLUT event callbacks
264 // - Directly redirect GLUT mouse button events to AntTweakBar
265 glutMouseFunc((GLUTmousebuttonfun)TwEventMouseButtonGLUT);
266 // - Directly redirect GLUT mouse motion events to AntTweakBar
267 glutMotionFunc((GLUTmousemotionfun)TwEventMouseMotionGLUT);
268 // - Directly redirect GLUT mouse "passive" motion events to AntTweakBar (same as MouseMotion)
269 glutPassiveMotionFunc((GLUTmousemotionfun)TwEventMouseMotionGLUT);
270 // - Directly redirect GLUT key events to AntTweakBar
271 glutKeyboardFunc((GLUTkeyboardfun)TwEventKeyboardGLUT);
272 // - Directly redirect GLUT special key events to AntTweakBar
273 glutSpecialFunc((GLUTspecialfun)TwEventSpecialGLUT);
274 // - Send 'glutGetModifers' function pointer to AntTweakBar;
275 // required because the GLUT key event functions do not report key modifiers states.
276 TwGLUTModifiersFunc(glutGetModifiers);
277
278 // Create some 3D objects (stored in display lists)
279 glNewList(SHAPE_TEAPOT, GL_COMPILE);
280 glutSolidTeapot(1.0);
281 glEndList();
282 glNewList(SHAPE_TORUS, GL_COMPILE);
283 glutSolidTorus(0.3, 1.0, 16, 32);
284 glEndList();
285 glNewList(SHAPE_CONE, GL_COMPILE);
286 glutSolidCone(1.0, 1.5, 64, 4);
287 glEndList();
288
289 // Create a tweak bar
290 bar = TwNewBar("TweakBar");
291 TwDefine(" GLOBAL help='This example shows how to integrate AntTweakBar with GLUT and OpenGL.' "); // Message added to the help bar.
292 TwDefine(" TweakBar size='200 400' color='96 216 224' "); // change default tweak bar size and color
293
294 // Add 'g_Zoom' to 'bar': this is a modifable (RW) variable of type TW_TYPE_FLOAT. Its key shortcuts are [z] and [Z].
295 TwAddVarRW(bar, "Zoom", TW_TYPE_FLOAT, &g_Zoom,
296 " min=0.01 max=2.5 step=0.01 keyIncr=z keyDecr=Z help='Scale the object (1=original size).' ");
297
298 // Add 'g_Rotation' to 'bar': this is a variable of type TW_TYPE_QUAT4F which defines the object's orientation
299 TwAddVarRW(bar, "ObjRotation", TW_TYPE_QUAT4F, &g_Rotation,
300 " label='Object rotation' opened=true help='Change the object orientation.' ");
301
302 // Add callback to toggle auto-rotate mode (callback functions are defined above).
303 TwAddVarCB(bar, "AutoRotate", TW_TYPE_BOOL32, SetAutoRotateCB, GetAutoRotateCB, NULL,
304 " label='Auto-rotate' key=space help='Toggle auto-rotate mode.' ");
305
306 // Add 'g_LightMultiplier' to 'bar': this is a variable of type TW_TYPE_FLOAT. Its key shortcuts are [+] and [-].
307 TwAddVarRW(bar, "Multiplier", TW_TYPE_FLOAT, &g_LightMultiplier,
308 " label='Light booster' min=0.1 max=4 step=0.02 keyIncr='+' keyDecr='-' help='Increase/decrease the light power.' ");
309
310 // Add 'g_LightDirection' to 'bar': this is a variable of type TW_TYPE_DIR3F which defines the light direction
311 TwAddVarRW(bar, "LightDir", TW_TYPE_DIR3F, &g_LightDirection,
312 " label='Light direction' opened=true help='Change the light direction.' ");
313
314 // Add 'g_MatAmbient' to 'bar': this is a variable of type TW_TYPE_COLOR3F (3 floats color, alpha is ignored)
315 // and is inserted into a group named 'Material'.
316 TwAddVarRW(bar, "Ambient", TW_TYPE_COLOR3F, &g_MatAmbient, " group='Material' ");
317
318 // Add 'g_MatDiffuse' to 'bar': this is a variable of type TW_TYPE_COLOR3F (3 floats color, alpha is ignored)
319 // and is inserted into group 'Material'.
320 TwAddVarRW(bar, "Diffuse", TW_TYPE_COLOR3F, &g_MatDiffuse, " group='Material' ");
321
322 // Add the enum variable 'g_CurrentShape' to 'bar'
323 // (before adding an enum variable, its enum type must be declared to AntTweakBar as follow)
324 {
325 // ShapeEV associates Shape enum values with labels that will be displayed instead of enum values
326 TwEnumVal shapeEV[NUM_SHAPES] = { {SHAPE_TEAPOT, "Teapot"}, {SHAPE_TORUS, "Torus"}, {SHAPE_CONE, "Cone"} };
327 // Create a type for the enum shapeEV
328 TwType shapeType = TwDefineEnum("ShapeType", shapeEV, NUM_SHAPES);
329 // add 'g_CurrentShape' to 'bar': this is a variable of type ShapeType. Its key shortcuts are [<] and [>].
330 TwAddVarRW(bar, "Shape", shapeType, &g_CurrentShape, " keyIncr='<' keyDecr='>' help='Change object shape.' ");
331 }
332
333 // Store time
334 g_RotateTime = GetTimeMs();
335 // Init rotation
336 SetQuaternionFromAxisAngle(axis, angle, g_Rotation);
337 SetQuaternionFromAxisAngle(axis, angle, g_RotateStart);
338
339 // Call the GLUT main loop
340 glutMainLoop();
341
342 return 0;
343 }
344
345