Added timer_callback sample for user callbacks

This commit is contained in:
Rcmaniac25 2017-05-29 20:25:42 -04:00
parent df67607c0a
commit 4fe9d11e56
2 changed files with 175 additions and 0 deletions

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@ -535,6 +535,7 @@ IF(UNIX)
ENDIF() ENDIF()
ADD_DEMO(subwin progs/demos/subwin/subwin.c) ADD_DEMO(subwin progs/demos/subwin/subwin.c)
ADD_DEMO(timer progs/demos/timer/timer.c) ADD_DEMO(timer progs/demos/timer/timer.c)
ADD_DEMO(timer_callback progs/demos/timer_callback/timer.c)

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@ -0,0 +1,174 @@
/* Timer (callback) demo
*
* Written by John Tsiombikas <nuclear@member.fsf.org>
* Modified by Vincent Simonetti
*
* A modification of the timer sample, but with this
* offering a use of the user-data callback.
*/
#include <stdio.h>
#include <GL/freeglut.h>
struct display_index_s
{
/* color index will be advanced every time the timer expires */
int surround_color_index;
int center_color_index;
};
typedef struct display_index_s display_index_t;
struct timer_state_s
{
int* color_index_ptr;
int* timer_time_ptr;
};
typedef struct timer_state_s timer_state_t;
struct menu_state_s
{
int* timer_time_ptr;
int menu_id;
};
typedef struct menu_state_s menu_state_t;
void disp(void* uptr);
void timer_func(int which, void* uptr);
const float color[][3] = {
{1, 0, 0},
{0, 1, 0},
{0, 0, 1},
{1, 1, 0},
{0, 1, 1},
{1, 0, 1}
};
const int timerInts[] = {
250,
500,
1000
};
void createMenuEntries(menu_state_t* menuState)
{
int i;
for (i = 0; i < sizeof(timerInts) / sizeof(*timerInts); i++)
{
char temp[10] = {'\0'};
/* flag current value */
if ((*menuState->timer_time_ptr) == timerInts[i])
temp[0] = '+';
else
temp[0] = '-';
sprintf(temp + 1, " %4d ms", timerInts[i]);
glutAddMenuEntry(temp, timerInts[i]);
}
}
void updateMenuEntries(menu_state_t* menuState)
{
int i;
for (i = 0; i < sizeof(timerInts) / sizeof(*timerInts); i++)
{
char temp[10] = { '\0' };
/* flag current value */
if ((*menuState->timer_time_ptr) == timerInts[i])
temp[0] = '+';
else
temp[0] = '-';
sprintf(temp + 1, " %4d ms", timerInts[i]);
glutChangeToMenuEntry(i+1, temp, timerInts[i]);
}
}
void MenuHandler(int timerInt, void* user_ptr)
{
menu_state_t* menuState;
if (!user_ptr)
{
/* In case main menu is selected somehow */
return;
}
menuState = (menu_state_t*)user_ptr;
*menuState->timer_time_ptr = timerInt;
glutSetMenu(menuState->menu_id);
updateMenuEntries(menuState);
}
int main(int argc, char **argv)
{
int timerSurroundInt = 1000, timerCenterInt = 500;
display_index_t displayIndex = { 0, 2 };
timer_state_t surroundTimerState = { &displayIndex.surround_color_index, &timerSurroundInt };
timer_state_t centerTimerState = { &displayIndex.center_color_index, &timerCenterInt };
menu_state_t surroundMenuState = { &timerSurroundInt, 0 };
menu_state_t centerMenuState = { &timerCenterInt, 0 };
glutInit(&argc, argv);
glutInitWindowSize(128, 128);
glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
glutCreateWindow("timer test");
glutDisplayFuncUcall(disp, &displayIndex);
/* get timer started, its reset in the timer function itself */
glutTimerFuncUcall(timerSurroundInt, timer_func, 1, &surroundTimerState);
glutTimerFuncUcall(timerCenterInt, timer_func, 2, &centerTimerState);
/* menus for setting timing */
surroundMenuState.menu_id = glutCreateMenuUcall(MenuHandler, &surroundMenuState);
createMenuEntries(&surroundMenuState);
centerMenuState.menu_id = glutCreateMenuUcall(MenuHandler, &centerMenuState);
createMenuEntries(&centerMenuState);
glutCreateMenuUcall(MenuHandler, NULL); /* doesn't matter, no clickable entries in this menu */
glutAddSubMenu("Center", centerMenuState.menu_id);
glutAddSubMenu("Surround", surroundMenuState.menu_id);
glutAttachMenu(GLUT_RIGHT_BUTTON);
glutMainLoop();
return 0;
}
void disp(void* user_ptr)
{
const display_index_t* displayIndex;
int cidx, pcidx;
displayIndex = (display_index_t*)user_ptr;
cidx = displayIndex->surround_color_index;
glClearColor(color[cidx][0], color[cidx][1], color[cidx][2], 1);
glClear(GL_COLOR_BUFFER_BIT);
pcidx = displayIndex->center_color_index;
glPointSize(10.f);
glColor3f(color[pcidx][0], color[pcidx][1], color[pcidx][2]);
glBegin(GL_POINTS);
glVertex2i(0,0);
glEnd();
glutSwapBuffers();
}
void timer_func(int which, void* user_ptr)
{
const timer_state_t* timerState;
timerState = (timer_state_t*)user_ptr;
/* advance the color index and trigger a redisplay */
*timerState->color_index_ptr = (*timerState->color_index_ptr + 1) % (sizeof color / sizeof *color);
glutPostRedisplay();
/* (re)set the timer callback and ask glut to call it in x ms */
glutTimerFuncUcall(*timerState->timer_time_ptr, timer_func, which, user_ptr);
}