I have made a game in OpenGL, and also have added a menu item. when I right click on the OpenGL Screen, the menu item is displayed and I have added an option "Reset Game" in it. How Can I clear all the variables involved in the game by clicking on this (Any clear or flush function?).
Here is my code
glutCreateMenu(menu);
glutAddMenuEntry("Reset Game", 1);
void menu(int item)
{
switch (item)
{
case 1:
{
//Adding a function here to clear all the variables
}
break;
}
}
You just need to code up the routine to reset all your variables to their default values.
void Reset()
{
score = 0;
lives = 3;
// etc.
}
OpenGL doesn't know what these are so you have to do it yourself.
Related
I am programming an LED Cube I have designed. The cube has a "pause" button and a "play/next" button. Unless the cube is paused, it will cycle through all of the different effects (animations) I've made for it. If you press the pause button, the cube will no longer transition between effects and will instead repeat the current effect. Pressing the 'play/next' button will unset the pause feature and will advance to the next effect immediately.
Some of these effects are pretty complex and require a large number of variables to be kept between frames of animation. In order to easily destroy all of these variables at a moment's notice (like when the next button is pressed), I'm instantiating the current animation as an object and destroying it when the effect is complete or the skip button is pressed.
I'm trying to set my main loop up as follows:
void loop() {
//create an effect object
switch(effectIndex){
case 0:
EF_GROWFRAME effect;
break;
case 1:
EF_RANDOMFILL effect;
break;
}
bool proceed;
do{
//returns false until the effect has completed
proceed=effect.step();
//push this cube update and wait for it to display
cube.update();
cube.waitForFrame();
}
while ((!proceed)&&(!skipflag));
//skipflag is set true during a timer interrupt if the skip button is freshly pressed
skipflag=false;
cube.clearPattern();
if (play) effectIndex++;
if (effectIndex=effectCount) effectIndex=0;
}
That fails because of my conflicting definitions of effect though. You can probably see what I'm going for, so what's the proper way to approach this?
This is a use case for polymorphism.
Define a base class, Animation that defines a shared interface and have your various animation types derive from it. For example:
class Animation {
public:
virtual ~Animation() {
// any generic cleanup shared by all animation types
}
virtual bool step() = 0;
};
class AnimationA : public Animation {
public:
bool step() override {
// logic for this type of animation
}
};
class AnimationB : public Animation {
public:
bool step() override {
// logic for this type of animation
}
};
void loop() {
std::unique_ptr<Animation> effect;
switch (effectIndex) {
case 0:
effect = std::make_unique<AnimationA>();
break;
case 1:
effect = std::make_unique<AnimationB>();
break;
}
//...
}
Live Demo
Since it seems like this may be an embedded environment, you could avoid the dynamic memory allocation from my first example by factoring your animation playing logic out into a separate function:
void playAnimation(Animation& effect) {
bool proceed;
do{
//returns false until the effect has completed
proceed=effect.step();
//push this cube update and wait for it to display
cube.update();
cube.waitForFrame();
} while (!proceed && !skipFlag);
//skipflag is set true during a timer interrupt if the skip button is freshly pressed
skipflag=false;
cube.clearPattern();
}
void loop() {
switch (effectIndex) {
case 0:
{
AnimationA effect;
playAnimation(effect);
break;
}
case 1:
{
AnimationB effect;
playAnimation(effect);
break;
}
}
if (play) effectIndex++;
if (effectIndex == effectCount) effectIndex=0;
}
Live Demo
I am trying to make a program where you are allowed to select between an option of shapes, and then drawing it. To allow for multiple shapes I created a vector of a class which creates shapes (Shapes are set up with the chosen function). My problem is the mouse click is too long, so it assigns it to everything in the vector, so you can't create a new shape. Is there a problem in my logic, or is there a problem in the code?
Here is my attempt:
for (auto& it : onCanvas) {
if (Mouse::isButtonPressed(Mouse::Left)) {
if (mousepointer.getGlobalBounds().intersects(circleOption.getGlobalBounds())) {
it.chosen(circles);
}
if (mousepointer.getGlobalBounds().intersects(rectOption.getGlobalBounds())) {
it.chosen(rectangle);
}
if (mousepointer.getGlobalBounds().intersects(triOption.getGlobalBounds())) {
it.chosen(triangles);
}
if (mousepointer.getGlobalBounds().intersects(it.shape.getGlobalBounds()) || it.dragging) {
it.shape.setPosition(mousepointer.getPosition());
it.dragging = true;
}
}
if (!Mouse::isButtonPressed) {
it.dragging = false;
}
win.draw(it.shape);
}
Your source-code is a bit incomplete (what is onCanvas and mousepointer). But I guess the problem is that this snippet is called multiple times while your mouse is clicked. To avoid that you can do two thing.
In the first solution you use events, so you only add shapes when the state of the mousebutton changes (you can additionally listen to the MouseButtonReleased to simulate a full click):
if (event.type == sf::Event::MouseButtonPressed)
{
if (event.mouseButton.button == sf::Mouse::Left)
{
// Hit Detection
}
}
or second solution you remember the last state of the button (probably do the mouse check once outside of the for loop):
bool mouse_was_up = true;
if (mouse_was_up && Mouse::isButtonPressed(Mouse::Left)) {
mouse_was_up = false;
for (auto& it : onCanvas) {
// Hit Detection
}
}
else if (!Mouse::isButtonPressed(Mouse::Left))
mouse_was_up = true;
I would rather stick to the first solution because when your click is too short and your gameloop is in another part of the game logic, you can miss the click.
The code I've written displays the sf::Drawable objects only for the top state of the state stack. Rendering works fine for everything, except the sf::Text type, that does not change the color of the text when button.getText().setFillColor(sf::Color:Red) is called. However, when I construct a button with a red text, whenever I try to set another color to that button, I only get a white text, no matter what color I request.
Here's where I change the color of a button:
void GameState_MainMenu::handleRealTimeInput()
{
for each (TextButton button in mButtons)
{
if (button.isSpriteClicked())
{
button.getText().setFillColor(sf::Color::Red);
button.triggerAction();
sf::Clock wait;
sf::Time timer = sf::Time::Zero;
timer = sf::seconds(0.15f);
while (wait.getElapsedTime() < timer)
{
}
wait.restart();
}
}
}
and this is my Game::render() method:
void Game::render()
{
GameState *currentState = getActiveState();
if (currentState != nullptr)
{
mWindow.clear();
currentState->draw();
}
mWindow.display();
}
Lastly, this is the draw method of the MainMenu state:
void GameState_MainMenu::draw()
{
game->mWindow.draw(game->mBackground);
game->mWindow.draw(mSelector.mSprite);
for each (TextButton button in mButtons)
{
game->mWindow.draw(button.getText());
}
}
It's probably because you have a while loop in the GameState_MainMenu::handleRealTimeInput that the program is getting stuck in.
You can try to use threads, though that way could get pretty messy. I suggest revising your code.
Okay, so I figured out this had something to do with c++'s for each instruction. As soon as I switched to the classic array-like traversal, my buttons started changing colors. I'm not saying this is THE solution, just that it worked for me. If anyone has the same problem, you might want to check that.
I need some help with my SFML/C++ code in Visual C++ 2010 Express Edition. I am trying to get my text (livesLeft) to "You Win!" Before the program sleeps. This is making the player know that he won. But instead, the program goes right to sleep and changes the text right as it is closing, so you only see it change for a few milliseconds. I can't even read it.
bool play = true;
bool win = false;
bool touchFinish = false;
int lives = 3;
sf::Font arial;
if(arial.loadFromFile("Fonts/arial.ttf") == 0)
{
return 1;
}
sf::Text livesLeft;
livesLeft.setFont(arial);
livesLeft.setCharacterSize(30);
livesLeft.setString("Lives: ");
livesLeft.setPosition(0, 0);
livesLeft.setColor(sf::Color::White);
sf::RectangleShape finish;
finish.setSize(sf::Vector2f(200, 600));
finish.setPosition(700, 0);
finish.setFillColor(sf::Color::Green);
Those are my variables in use and this is my code where I'm trying to change the text:
if(player.getGlobalBounds().intersects(finish.getGlobalBounds()))
{
livesLeft.setString("You Win!");
touchFinish = true;
}
if(touchFinish)
{
win = true;
}
if(win)
{
Sleep(5000);
play = false;
}
I also forgot to add in that I do have the rendering at the end:
window.clear();
window.draw(livesLeft);
window.draw(finish);
window.draw(player);
window.draw(obs1);
window.draw(obs2);
window.draw(obs3);
window.draw(obs4);
window.draw(obs5);
window.draw(obs6);
window.draw(obs7);
window.draw(obs8);
window.draw(obs9);
window.draw(obs10);
window.draw(obs11);
window.draw(obs12);
window.draw(obs13);
window.display();
This is most likely due to the fact that you aren't calling the display method for you window. Telling the text to change simply prepares the next framebuffer to display the new text, but because you never tell the window to update its display before sleeping, it never displays the new framebuffer.
Here is a quick example of a simple program using SFML. Notice the window.display() method at the end of the main game loop.
You effectively want to be doing this:
if(win)
{
window.display();
Sleep(5000);
play = false;
}
The reason why you need to update the display before hand again is because Sleep(5000); blocks the thread, essentially meaning that it sits at that call for 5000ms. Also, if you want to keep the previous items on the screen, you'll want to redraw those before window.display(); as well, since these won't be in the next framebuffer.
I have an OpenGL project which loads an object file, after the object is loaded i want to be able to move it with keyboard smoothly, so i wrote this block of code to do the job:
while (remains) {
if (x_remains) {
refPosition[0] += speed.x;
if (refPosition[0] > nextPos[0]) {
x_remains = false;
}
}
if (y_remains) {
refPosition[1] += speed.y;
if (refPosition[1] > nextPos[1]) {
y_remains = false;
}
}
if (z_remains) {
refPosition[2] += speed.z;
if (refPosition[2] >= nextPos[2]) {
z_remains = false;
}
}
remains = x_remains || y_remains || z_remains;
glutPostRedisplay();
}
as you see I want to redisplay the scene in the while but when this is executed glutpostredisplay() just sets a flag and the scene is redrawn in the next iteration of the mainloop. my question is how can I redraw the scene before next loop of the while and before the function returns
You won't lose performance or see jerky rendering by going through glutPostRedisplay instead of drawing directly. (Or, if every microsecond really is that precious, why the heck are you using GLUT to begin with?)
On some systems you CAN'T draw outside the display function anyway, because the GL context won't be valid.
This is not unique to GLUT either. All the modern graphics/GUI toolkits I'm familiar with also require you to have a designated display function that gets invoked by an event handler, whether it's WM_PAINT messages, NSView drawRect:, or whatever.
If your program is not updating smoothly, it will be for some other reason.