I made a galaxy sketch in p5.js using rotates and radians, but it's erased each time the background() is loaded as draw() runs. Is there a way to over-ride the background() function? I want the galaxies to remain in view.
var stars;
function preload(){
//for (var i = 0; i < planetArray.length; i++) {
//stars = loadImage('Assets/stars.png');
}
function setup(){
createCanvas(windowWidth, windowHeight);
}
function draw() {
//background(0);
star()
//function mousepressed(){
}
function star(){
//angle = map(mouseX, 0,width, 0,360);
//rotate(radians(angle*100));
noStroke();
//translate(width/2, height/2);
translate(mouseX,mouseY);
fill(0);
rotate(radians(frameCount%360)); //rotates output of ellipses
rotate(radians(1000*frameCount%360));
for(var i =0; i < 20; i++){
push();
noStroke();
fill(random(200),0,random(150),random(2));
// fill(random(125),random(250),random(100));
ellipse(10*frameCount % (width/10),0,10,10);
//image(stars, 10*frameCount % (width/2),0,10,10)
//image((10*frameCount % (width/2),0,10,10)
//
pop();
}
}
Well, there really isn't any magic to it. Calling the background() function fills the window with a solid color (or image) and draws over anything you've previously drawn.
The solution to this problem isn't to "over-ride" the background() function. It's to restructure your program so your stuff gets drawn properly. Exactly how you do that depends on exactly what you want to happen.
Option 1: Only call the background() function once.
If you just want a black background at the beginning, and everything you do from the draw() function should still add up, then maybe you just want to call the background() function once. You could do it as the last line in your setup() function, for example.
Option 2: Store everything you want to draw in a data structure.
This is probably the most typical case. If you want a background to be drawn behind shapes that are moving around, you're going to have to store those shapes in some kind of data structure, and then draw all of them every single frame.
Option 3: Draw to an off-screen image, and then draw that image on top of your background.
This is a bit of a mix between the first two options. You can draw everything (except the background) to an off-screen PImage, and then draw the background to the screen, then draw the image to the screen. This allows you to have a background that changes colors without having to redraw everything else.
Which option you choose really depends on exactly what you want to happen.
Related
I'm trying to use an animation for a sudoku app. I want for everytime i insert a wrong number, that number would change color and it's scale.
My code is:
override fun onDraw(canvas: Canvas?) {
canvas ?: return
drawBoard(canvas)
drawNumberProblem(canvas)
}
private fun drawNumberProblem(canvas: Canvas){
paint.color=darkcolor
paint.textSize = cellSide*3/4
SudokuGame.numbersproblem.forEach { e->
canvas.drawText("${e.number}", originX + e.col * cellSide+cellSide/5, originX + (e.row+1) * cellSide-cellSide/10, paint)
}
}
And i tried:
private fun initAnimation() {
var animation = RotateAnimation(0f, 360f, 150f, 150f)
animation.setRepeatCount(Animation.INFINITE)
animation.setRepeatMode(Animation.RESTART)
animation.setDuration(7500L)
animation.interpolator = LinearInterpolator()
startAnimation(animation)
}
override fun onDraw(canvas: Canvas?) {
canvas ?: return
if(animation==null)
initAnimation()
drawBoard(canvas)
drawNumberProblem(canvas)
}
private fun drawNumberProblem(canvas: Canvas){
paint.color=darkcolor
paint.textSize = cellSide*3/4
SudokuGame.numbersproblem.forEach { e->
canvas.drawText("${e.number}", originX + e.col * cellSide+cellSide/5, originX + (e.row+1) * cellSide-cellSide/10, paint)
}
}
The animation, the board and the numbers are all good. The animation is only an example, i tried to rotate it to see if it's working. But the only problem is that the animation is working for the whole board, i want to have animation only over numbers.
Is there any way to create a initAnimation with a parameter like initAnimation(drawNumberProblem())?
I am new to kotlin animation, so i don't really care about the best way to do it, i want to find a simple way to understand it.
Thanks
If each cell is its own View (say a TextView) you can animate it the way you're trying to, and the animation framework will take care of the timing, the rotation and scaling, etc. Because each view is separate, they can all be animated independently, using Android's view animation libraries, and a lot of the work is taken care of for you - it's pretty easy to use!
If it's all one view, and you're drawing a bunch of elements which can all be animated, you have to keep track of those elements, any animations that should be happening to each one, and how each animation's state affects the element when it comes time to draw it. Instead of each view having its own state and being drawn separately, you have to draw the whole thing at once, because it's a single view. So you need to keep track of those individual element states yourself, so you can refer to them when drawing the current overall state.
So for example, say you've got an animation where an element needs to scale to 2x the size and then back to normal, and it runs for 1 second total (1000ms). When you come to draw that element, you need to know how far along that animation you are at that moment, so you can scale it appropriately, and draw it at the correct size.
There are lots of ways to do this, probably some smarter ones, but this is the most basic hands-on example I think. I'm not testing this, but hopefully it gives you the idea:
// for brevity, so we can just say "now" instead of writing out the whole function call
val now: Long get() = System.currentTimeMillis()
// store a start time for each grid cell (or null if there's no anim running)
val animStartTimes = Array(CELL_COUNT)<Long?>
val animLength = 1000 // millis
// Basic function to start an animation - you could adapt this to prevent restarts
// while an anim is already running, etc
fun startAnim(cellIndex: Int) {
animStartTimes[cellIndex] = now
// tell the view it needs to redraw (since we're animating something now)
invalidate()
}
// Get the current progress of an animation in a cell, from 0% to 100% (0.0 to 1.0)
// I'm treating a finished item as "reset" to its original state
fun getAnimProgress(cellIndex: Int): Float {
val start = animStartTimes[cellIndex]
if (start == null) return 0f
val progress = (now - start) / animLength
if (progress > 1f) {
// animation has ended (past 100% of its runtime) so let's clear it
animStartTimes[cellIndex] = null
return 0f // like I said, I'm treating finished animations as "reset" to 0%
} else return progress
}
override fun onDraw(canvas: Canvas) {
// this flag can be set to true if we find an element that's still animating,
// so we can decide whether to call invalidate() again (forcing a redraw next frame)
var animating = false
items.forEachIndexed { i, item ->
val animProgress = getAnimProgress(i)
if (animProgress > 0f) animating = true // set that flag
// now you need to use that 0.0-1.0 value to calculate your animation state,
// e.g. adjusting the text size by some factor - 0.0 should produce your "default" state
}
// finally, force a redraw next frame if necessary - only do this when your view
// contents might need to change, otherwise you're wasting resources
if (animating) invalidate()
}
I hope that makes sense - obviously I haven't shown how to actually draw the states of your animation, that depends on exactly what you're doing - but that's the basics of it. It's a lot more work than using view animation, but it's not too bad when you get the idea.
The drawing part is a little more complex, and you'll probably want to get familiar with manipulating the Canvas - e.g. to draw a rotated character, you turn the canvas, draw the character as normal, then undo the canvas rotation so it's the right way up again, and the character is tilted. I don't have time to look for any tutorials about it, but this article covers the matrix operations that scale/rotate/etc the canvas
So yeah, it's a bit involved - and depending on what you want to do, a grid of TextViews might be a better shout
I try to delete a square when I input the number as "1" into the program. How can I delete it?
sf::RectangleShape rec1(sf::Vector2f(50, 100));
rec1.setPosition(200, 700 );
rec1.setFillColor(sf::Color(100, 250, 50));
window.draw(rec1);
int num;
cout << "Please enter a number: ";
cin >> num;
SFML itself won't track what's drawn on screen – you'll have to do that yourself – and you're supposed to redraw the window contents when needed.
A basic "main loop" for a SFML based program would typically look like this:
while (window.isOpen()) {
sf::Event event;
while (window.pollEvent(event)) {
// Handle events here
}
// Update your program logic here
window.clear();
// Draw your stuff here
window.display();
}
Depending on what you draw, you determine what's visible on screen. So if you want your rectangle to no longer appear, simply no longer call window.draw(rectangle);. How you achieve this – e.g. by removing the rectangle from a std::vector<sf::Drawable*> that's iterated over while drawing – is up to you.
You can't delete it when you created it like that. you can color it as transparent using sf::Color::Transparent and it will become unseenable.
If you want to delete it. you have to make it a pointer first. or wrap it out of a class that handles it.
auto rect = make_unique<sf::Rectangle>(sf::Vector2f(50, 100));
and then use std::unique_ptr::reset() to delete it.
rect.reset();
Iv looked around online for a solution to this issue but iv been unable to solve it.
I want to extend the sprite class to make my own interactive circle. Everything works but setting the X,Y, Width and height of the custom class does not work:
class CircleDraw extends Sprite
{
public function new(x:Int,y:Int,width:Int,height:Int)
{
super();
this.x = x;
this.y = y;
this.width = width;
this.height = height;
drawCircle();
}
private function drawCircle()
{
this.graphics.beginFill(0xffffff);
this.graphics.drawCircle(this.x,this.y, this.width);
this.graphics.endFill();
}
}
The approach above does not work as expected, setting x,y and width via the constructor results in literally nothing appearing. Yet if i set them manually, either within the class
this.graphics.drawCircle(200,200, 30);
Or prior to addChild:
circle = new CircleDraw(10,10,100,200);
circle.x=100;
circle.y=100;
it then appears on screen. also after adding it like so once the values have been added manually within the class rather than this.x etc:
circle = new CircleDraw(10,10,100,200);
addChild(circle);
So my question is this, how do i extend a class (Sprite) and allow the constructor to modify its parents default variables and keep the values?
EDIT
Just to provide all the code as requested:
This does not work:
circle = new CircleDraw(10,10,100,200);
addChild(circle);
when Circle draw is like this:
class CircleDraw extends Sprite
{
public function new(x:Int,y:Int,width:Int,height:Int)
{
super();
this.x = x;
this.y = y;
this.width = width;
this.height = height;
drawCircle();
}
private function drawCircle()
{
this.graphics.beginFill(0xffffff);
this.graphics.drawCircle(this.x, this.y, this.width);
this.graphics.endFill();
}
}
It does work if i modify the method:
private function drawCircle()
{
this.graphics.beginFill(0xffffff);
this.graphics.drawCircle(200, 200, 30);
this.graphics.endFill();
}
Or if during the instancing of the object i set the X and Y variables as mentioned before the edit.
You are indeed setting the base class variables successfully, it's just that DisplayObject.width has a rather specific (and perhaps not that obvious) behavior.
width:Float
Indicates the width of the display object, in pixels. The width is calculated based on the bounds of the content of the display object. When you set the width property, the scaleX property is adjusted accordingly, as shown in the following code:
Except for TextField and Video objects, a display object with no content(such as an empty sprite) has a width of 0, even if you try to set width to a different value.
—OpenFL API: DisplayObject: width
In this sense, OpenFL follows the ActionScript 3.0 API.
From what I can surmise, it looks like you're trying to override a constructor (new) that takes no arguments.
I'm not entirely sure, but that might not get you what you want. What I think you're actually doing is just creating a method "new" on the extended class, and then within it, feeding the parent nothing (super()). So the parent will not have the constructor arguments. It would be interesting to do look at that object in a debugger and look at the instance properties vs. the parent ones.
There's probably a way around that, but I think you might want to look at doing this via composition instead of inheritance. For example, in "new", create a new instance of a sprite, and manipulate the properties of that.
class MySprite
{
public var sprite : Sprite;
public function new ( ) {
sprite = new Sprite ();
}
}
You would then perform your operations on that sprite instance. Essentially, you are just wrapping a sprite in your own class. Decorator, more or less.
I found some reference to the topic here (it's been a while since I did any Flash programming), it shows addChild and removeChild implementations, etc.
http://old.haxe.org/forum/thread/685
From the (partial) code you posted, it looks it should work.
In other words, setting parent's variables like that should work.
I doubt there are some other code you didn't post gets in the way. I suggest you print out the x, y values in the drawCircle call to debug.
I also doubt the circle is drawn off-screen so you can't see it. Because you first moved the sprite, to (x,y) and then draw a circle in (x,y) inside the sprite. So effectively the circle is at (2x,2y) in global space
EDIT:
this.graphics.drawCircle(200,200, 30);
You claim this worked. Should draw at (210,210) with radius 30
circle = new CircleDraw(10,10,100,200);
circle.x=100;
circle.y=100;
You claim this worked. Should draw at (200,200) with radius 100
circle = new CircleDraw(10,10,100,200);
addChild(circle);
You claim this didn't work. Should draw at (20,20) with radius 100
From the above three version, you are actually drawing at different places with different sizes. So I still suspect that "didn't work" may due to the fact that you are drawing at some places not in sight.
So I still suggest you print out the value of x, y, width inside the private drawCircle function to see what's happening
Be aware, that you are kind of dealing with 2 coordinate spaces. The one were the Sprite will be added and the graphics object of that Sprite. If you set this.x and this.width you are actually setting properties of this Sprite. So in regards of positing you are moving the Sprite itself in that case. The Sprite "graphics" property has it's own coordinate space.
For example if you pass x=100 in your CircleDraw constructor function you are first moving the sprite itself by x=100 and then draw the circle with an x offset of 100. So if you would add the sprite directly to the Stage you would start drawing your circle actually at x=200, because you effectively applied the position twice. It seems to me this is not what you actually are intending.
Also your CircleDraw instance (which is also a Sprite of course) is "empty" when you are constructing it. So calling this.width = width in your constructor has no effect. this.width will stay 0 because the Sprite has no contents at that point. So in the drawCircle method you are drawing a circle with a width of 0.
Probably the better solution would be to simply pass the arguments of your constructor function to your drawCircle function, without setting any properties.
I want to have a fullscreen mode that keeps the aspect ratio by adding black bars on either side. I tried just creating a display mode, but I can't make it fullscreen unless it's a pre-approved resolution, and when I use a bigger diaplay than the native resolution the pixels become messed up, and lines appeared between all of the tiles in the game for some reason.
I think I need to use FBOs to render the scenario to a texture instead of the window, and then just use a fullscreen approved resolution and render the texture properly stretched out in the center of the screen, but I just don't understand how to render to a texture in order to do that, or how to stretch an image. Could someone please help me?
EDIT
I got fullscreen working, but it makes everything all broken looking There are random lines on the edges of anything that's written to the window. There are no glitchy lines when it's in native resolution though. Here's my code:
Display.setTitle("Mega Man");
try{
Display.setDisplayMode(Display.getDesktopDisplayMode());
Display.create();
}catch(LWJGLException e){
e.printStackTrace();
}
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0,WIDTH,HEIGHT,0,1,-1);
glMatrixMode(GL_MODELVIEW);
glEnable(GL_TEXTURE_2D);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
glHint(GL_LINE_SMOOTH_HINT, GL_NICEST);
try{Display.setFullscreen(true);}catch(Exception e){}
int sh=Display.getHeight();
int sw=WIDTH*sh/HEIGHT;
GL11.glViewport(Display.getWidth()/2-sw/2, 0, sw, sh);
Screenshot of the glitchy fullscreen here: http://sta.sh/021fohgnmxwa
EDIT
Here is the texture rendering code that I use to draw everything:
public static void DrawQuadTex(Texture tex, int x, int y, float width, float height, float texWidth, float texHeight, float subx, float suby, float subd, String mirror){
if (tex==null){return;}
if (mirror==null){mirror = "";}
//subx, suby, and subd are to grab sprites from a sprite sheet. subd is the measure of both the width and length of the sprite, as only images with dimensions that are the same and are powers of 2 are properly displayed.
int xinner = 0;
int xouter = (int) width;
int yinner = 0;
int youter = (int) height;
if (mirror.indexOf("h")>-1){
xinner = xouter;
xouter = 0;
}
if (mirror.indexOf("v")>-1){
yinner = youter;
youter = 0;
}
tex.bind();
glTranslatef(x,y,0);
glBegin(GL_QUADS);
glTexCoord2f(subx/texWidth,suby/texHeight);
glVertex2f(xinner,yinner);
glTexCoord2f((subx+subd)/texWidth,suby/texHeight);
glVertex2f(xouter,yinner);
glTexCoord2f((subx+subd)/texWidth,(suby+subd)/texHeight);
glVertex2f(xouter,youter);
glTexCoord2f(subx/texWidth,(suby+subd)/texHeight);
glVertex2f(xinner,youter);
glEnd();
glLoadIdentity();
}
Just to keep it clean I give you a real answer and not just a comment.
The aspect ratio problem can be solved with help of glViewport. Using this method you can decide which area of the surface that will be rendered to. The default viewport will cover the whole surface.
Since the second problem with the corrupt rendering (also described here https://stackoverflow.com/questions/28846531/sprite-game-in-full-screen-aliasing-issue) appeared after changing viewport I will give my thought about it in this answer as well.
Without knowing exactly how the rendering code for the tile background looks. I would guess that the problem is due to any differences in the resolution between the glViewport and glOrtho calls.
Example: If the glOrtho resolution is half the viewport resolution then each openGL unit is actually 2 pixels. If you then renders a tile between x=0 and x=9 and then the next one between x=10 and x=19 you will get an empty space between them.
To solve this you can change the resolution so that they are the same. Or you can render the tile to overlap, first one x=0 to x=10 second one x=10 to x=20 and so on.
Without seeing the tile rendering code I can't verify it this is the problem though.
I am trying to implement a zoom in function to my app.
The idea is when I chose to zoom in, the graph should expand horizontally 2 times larger so that only half of the graph will be shown in the window, and one will need to scroll to see the other half despite the size of the window.
I have a zoom variable for zoom factor. Then in onDraw(CDC &pDC):
//...set pen and others...
CRect rect;
GetClientRect(rect);
for (int x=0; x < zoomFactor*rect.Width(); x++)
//....draw the graph
then in onToolsZoomin():
void CMyGraphView::OnToolsZoomin()
{
zoom *= 2;
CRect rect;
GetClientRect(rect);
CSize sizeTotal;
sizeTotal.cx = zoom*rect.Width();
sizeTotal.cy = 0;
SetScrollSizes(MM_TEXT, sizeTotal);
this->RedrawWindow();
}
When I run this, I can have the window correctly draw half of the graph and a scrollbar that indicate only half of the graph is shown. But when I try to scroll it, it goes back to the original position (bottom left) and the other half of the graph won't show up.
The parameters in both functions are not the same one. It can be the first reason of the problem.
Can you put the code that is suppose to call OnToolsZoomin please ? Is it handled through a WM_VSCROLL or WM_HSCROLL message ?
Is your function OnToolsZoomin called at all ?
Is you scrollbar properly initialized (scroll range) ?