1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
|
/* $Id: overlay.c,v 1.2 2009/05/14 20:43:34 vareille Exp $ */
/*
* Togl - a Tk OpenGL widget
* Copyright (C) 1996-1997 Brian Paul and Ben Bederson
* Copyright (C) 2006-2007 Greg Couch
* See the LICENSE file for copyright details.
*/
/*
* An example Togl program using an overlay.
*/
#define USE_TOGL_STUBS
#include "togl.h"
#include <stdlib.h>
#include <string.h>
#undef TCL_STORAGE_CLASS
#define TCL_STORAGE_CLASS DLLEXPORT
/* Overlay color indexes: */
static unsigned long Red, Green;
/*
* Togl widget create callback. This is called by Tcl/Tk when the widget has
* been realized. Here's where one may do some one-time context setup or
* initializations.
*/
static int
create_cb(ClientData clientData, Tcl_Interp *interp, int objc,
Tcl_Obj *const *objv)
{
Togl *togl;
if (objc != 2) {
Tcl_WrongNumArgs(interp, 1, objv, "pathName");
return TCL_ERROR;
}
if (Togl_GetToglFromObj(interp, objv[1], &togl) != TCL_OK) {
return TCL_ERROR;
}
/* allocate overlay color indexes */
Red = Togl_AllocColorOverlay(togl, 1, 0, 0);
Green = Togl_AllocColorOverlay(togl, 0, 1, 0);
/* in this demo we always show the overlay */
if (Togl_ExistsOverlay(togl)) {
Togl_ShowOverlay(togl);
printf("Red and green lines are in the overlay\n");
} else {
printf("Sorry, this display doesn't support overlays\n");
}
return TCL_OK;
}
/*
* Togl widget reshape callback. This is called by Tcl/Tk when the widget
* has been resized. Typically, we call glViewport and perhaps setup the
* projection matrix.
*/
static int
reshape_cb(ClientData clientData, Tcl_Interp *interp, int objc,
Tcl_Obj *const *objv)
{
int width;
int height;
float aspect;
Togl *togl;
if (objc != 2) {
Tcl_WrongNumArgs(interp, 1, objv, "pathName");
return TCL_ERROR;
}
if (Togl_GetToglFromObj(interp, objv[1], &togl) != TCL_OK) {
return TCL_ERROR;
}
width = Togl_Width(togl);
height = Togl_Height(togl);
aspect = (float) width / (float) height;
/* Set up viewing for normal plane's context */
glViewport(0, 0, width, height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(-aspect, aspect, -1, 1, -1, 1);
glMatrixMode(GL_MODELVIEW);
/* Set up viewing for overlay plane's context */
if (Togl_ExistsOverlay(togl)) {
Togl_UseLayer(togl, TOGL_OVERLAY);
glViewport(0, 0, width, height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(-1, 1, -1, 1, -1, 1);
glMatrixMode(GL_MODELVIEW);
Togl_UseLayer(togl, TOGL_NORMAL);
}
return TCL_OK;
}
/*
* Togl widget overlay display callback. This is called by Tcl/Tk when the
* overlay has to be redrawn.
*/
static int
overlay_display_cb(ClientData clientData, Tcl_Interp *interp, int objc,
Tcl_Obj *const *objv)
{
glClear(GL_COLOR_BUFFER_BIT);
glIndexi(Red);
glBegin(GL_LINES);
glVertex2f(-1, -1);
glVertex2f(1, 1);
glVertex2f(-1, 1);
glVertex2f(1, -1);
glEnd();
glIndexi(Green);
glBegin(GL_LINE_LOOP);
glVertex2f(-0.5f, -0.5f);
glVertex2f(0.5f, -0.5f);
glVertex2f(0.5f, 0.5f);
glVertex2f(-0.5f, 0.5f);
glEnd();
glFlush();
return TCL_OK;
}
/*
* Togl widget display callback. This is called by Tcl/Tk when the widget's
* contents have to be redrawn. Typically, we clear the color and depth
* buffers, render our objects, then swap the front/back color buffers.
*/
static int
display_cb(ClientData clientData, Tcl_Interp *interp, int objc,
Tcl_Obj *const *objv)
{
glClear(GL_COLOR_BUFFER_BIT);
glLoadIdentity();
glBegin(GL_TRIANGLES);
glColor3f(1, 0, 1);
glVertex2f(-0.5f, -0.3f);
glVertex2f(0.5f, -0.3f);
glVertex2f(0, 0.6f);
glColor3f(1, 1, 0);
glVertex2f(-0.5f + 0.2f, -0.3f - 0.2f);
glVertex2f(0.5f + 0.2f, -0.3f - 0.2f);
glVertex2f(0 + 0.2f, 0.6f - 0.2f);
glColor3f(0, 1, 1);
glVertex2f(-0.5f + 0.4f, -0.3f - 0.4f);
glVertex2f(0.5f + 0.4f, -0.3f - 0.4f);
glVertex2f(0 + 0.4f, 0.6f - 0.4f);
glEnd();
glFlush();
return TCL_OK;
}
/*
* Called by Tcl to let me initialize the modules (Togl) I will need.
*/
EXTERN int
Overlay_Init(Tcl_Interp *interp)
{
/*
* Initialize Tcl and the Togl widget module.
*/
if (Tcl_InitStubs(interp, "8.1", 0) == NULL
|| Togl_InitStubs(interp, "2.0", 0) == NULL) {
return TCL_ERROR;
}
/*
* Specify the C callback functions for widget creation, display,
* and reshape.
*/
Tcl_CreateObjCommand(interp, "create_cb", create_cb, NULL, NULL);
Tcl_CreateObjCommand(interp, "display_cb", display_cb, NULL, NULL);
Tcl_CreateObjCommand(interp, "reshape_cb", reshape_cb, NULL, NULL);
Tcl_CreateObjCommand(interp, "overlay_display_cb", overlay_display_cb, NULL,
NULL);
/*
* Make a new Togl widget command so the Tcl code can set a C variable.
*/
/* NONE */
/*
* Call Tcl_CreateCommand for application-specific commands, if
* they weren't already created by the init procedures called above.
*/
return TCL_OK;
}
|
