Make a jump with the CSFML library in C - c

Question

For a project I have to make a sprite jumping and I don't know how to do I already tested this
while(sfRenderWindow_pollEvent(window, &event)) {
if (event.type == sfEvtClosed) {
sfRenderWindow_close(window);
}
if (event.type == sfEvtKeyPressed) {
if (event.key.code == sfKeySpace || sfKeyUp)
jumping = 1;
}
}
if (jumping) {
while (clock < 60) {
printf("%f\n", dino_pos.y);
if (clock < 30) {
dino_pos.y -= 2;
sfSprite_setPosition(dino, dino_pos);
clock++;
} else if (clock < 60) {
dino_pos.y += 2;
sfSprite_setPosition(dino, dino_pos);
clock++;
}
}
if (clock >= 60)
clock = 0;
printf("Jump\n");
}
jumping = 0;
But he doesn't work, my program is in 60 fps so I want that the jump is 1 second duration. Printf is here to view what the position of my dino but I guess that the jump was instant so I don't have the time to see the jump. Do you have idea for do a jump ?

Answer 1

Your program logic should look like this:
Note: this is just a simplified version and not a working example. It should give you a hint how to do it.
int main()
{
openWindow();
while (active) {
getTime();
processMessages();
doLogic();
renderScene();
swapBuffers();
}
closeWindow();
}
void getTime()
{
// you have to know the time unit (sec, ms, us, ns, etc.)
current_time = systemTime();
}
void processMessages()
{
while (nextEvent()) {
if (EventType == EvtClosed) {
active = false;
}
if ((EventType == KeyPressed) && (KeyType == KeySpace) && !jumping) {
jump_start = current_time;
jumping = true;
}
}
}
void doLogic()
{
if (jumping) {
// time_frac has to be in range [0.0..1.0]
time_frac = (current_time - jump_start) / time_units_per_second;
// linear interpolation based on time fraction
pos = start_pos * (1 - time_frac) + end_pos * time_frac;
}
}
void renderScene()
{
printf("%f\n", pos);
}