I'm coding for a game and want the background to repeat itself.
xOffset = (int) (camera.getX() % WIDTH);
g.drawImage(bgInv, xOffset - WIDTH, 0, WIDTH, HEIGHT, null);
g.translate(xOffset, 0);
g.drawImage(bg, 0, 0, WIDTH, HEIGHT, null);
g.translate(-xOffset, 0);
g.drawImage(bgInv, xOffset + WIDTH, 0, WIDTH, HEIGHT, null);
The first drawImage draws when the camera's X is negative
and the third when the camera's X is positive.
bg is the normal background
bgInv is the background inverted
The problem is that when I'm moving and the xOffset goes from WIDTH to 0, it seems like there's a "wrap".
Click here to see
The console is outputting xOffset
I know it is because I'm using modulo to get xOffset but I didn't figure out a better way...
Thanks in advance
If I understood correctly, what you want to repeat is a 2 * WIDTH by HEIGHT image, where the left half is the background image and the right half is the same image horizontally inverted.
So what you can do is the following:
xOffset = (int) (camera.getX() % (2 * WIDTH));
// draw the background image at x = xOffset - 2 * WIDTH
g.drawImage(bg, xOffset - 2 * WIDTH, 0, WIDTH, HEIGHT, null);
g.drawImage(bgInv, xOffset - WIDTH, 0, WIDTH, HEIGHT, null);
// draw the background image at x = xOffset
g.drawImage(bg, xOffset, 0, WIDTH, HEIGHT, null);
g.drawImage(bgInv, xOffset + WIDTH, 0, WIDTH, HEIGHT, null);
Related
I need to resize alot of images from the ratio aspect (2:3) to (3:4).
The images are 800px x 1200px currently. I need them to be 600px x 800px eventually without any cropping.
May I know what libraries are available for me to do padding and resizing without cropping in Java?
From your current Image (assuming a java.awt.Image) you can use :
Image.getScaledInstance(w,h,h) as method
Image.SCALE_SMOOTH as algorithm for resize
And these steps:
compute the ratios in width and in height
depending on their values (padding width or padding height)
compute the width and height to obtain the scaled image
compute the padding required
write the image at the good position
static BufferedImage pad(BufferedImage image, double width, double height, Color pad) {
double ratioW = image.getWidth() / width;
double ratioH = image.getHeight() / height;
double newWidth = width, newHeight = height;
int fitW = 0, fitH = 0;
BufferedImage resultImage;
Image resize;
//padding width
if (ratioW < ratioH) {
newWidth = image.getWidth() / ratioH;
newHeight = image.getHeight() / ratioH;
fitW = (int) ((width - newWidth) / 2.0);
}//padding height
else if (ratioH < ratioW) {
newWidth = image.getWidth() / ratioW;
newHeight = image.getHeight() / ratioW;
fitH = (int) ((height - newHeight) / 2.0);
}
resize = image.getScaledInstance((int) newWidth, (int) newHeight, Image.SCALE_SMOOTH);
resultImage = new BufferedImage((int) width, (int) height, image.getType());
Graphics g = resultImage.getGraphics();
g.setColor(pad);
g.fillRect(0, 0, (int) width, (int) height);
g.drawImage(resize, fitW, fitH, null);
g.dispose();
return resultImage;
}
To use as
BufferedImage image = ...;
BufferedImage result = pad(image, 600, 800, Color.white);
Managed to do it using below code:
'w' is the amount of padding you need on each side.
BufferedImage newImage = new BufferedImage(image.getWidth()+2*w, image.getHeight(),
image.getType());
Graphics g = newImage.getGraphics();
g.setColor(Color.white);
g.fillRect(0,0,image.getWidth()+2*w,image.getHeight());
g.drawImage(image, w, 0, null);
g.dispose();
I think ffmpeg can help you to do anything with image.
e.g. Use ffmpeg to resize image
You can keep ffmpeg binaries in some conf folder.
Create sh script for ffmpeg command.
Use CommandLine from (Apache Commons exec library) to run the script.
rec.set(0, 0, canvas.getWidth(), canvas.getHeight()/2);
It creates the rectangle as expected, I know 0, 0 is x, y but how do I set y to the bottom so it stays at the bottom on all devices with different size?
you haven't given much information, so I'll state my assumptions
the x,y would be the top-left of your shape, so assuming that the canvas is the full height of the device:
x - 0, as you want the shape to start on the left edge, y - the height of the device minus the height of the shape
your code would be
int width = canvas.getWidth();
int height = canvas.getHeight()/2;
int x = 0;
int y = canvas.getHeight() - height;
rec.set(x, y, width, height);
I am doing something with JOGL libraries (forced to) and I can't figure out how to offset the center zero coordinates. I would like to offset them to the bottom of my viewport, in the method
public void reshape(GLAutoDrawable drawable, int x, int y, int width, int height)
but I can't google any way to translate int height into any meaningfull offset float coordinates.
edit:
gl.glViewport(0, 0, width, height);
gl.glMatrixMode(GL_PROJECTION);
gl.glLoadIdentity();
glu.gluPerspective(45.0, width / (float) height, 0.1, 100.0);
gl.glMatrixMode(GL_MODELVIEW);
gl.glLoadIdentity();
Solved using
glu.gluLookAt(0, 0, 1, 0, 0.42, 0, 0, 1, 0);
Didn't realize the offset wasn't relative.
I am creating a little game in Java and I have an image which gets rotated.
As you can see in the two images below, there is a giant ship which slowly rotates in the game, but when it gets to a certain point it gets cut off (due to its own little BufferedImage).
Heres my rendering code:
public void drawImageRotated(BufferedImage img, double x, double y, double scale, double angle) {
x -= xScroll;
y -= yScroll;
BufferedImage image = new BufferedImage((int)(img.getWidth() * 1.5D), (int)(img.getHeight() * 1.5D), 2);
Graphics2D g = (Graphics2D)image.getGraphics();
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g.rotate(Math.toRadians(angle), image.getWidth() / 2, image.getHeight() / 2);
g.drawImage(img, image.getWidth() / 2 - img.getWidth() / 2, image.getHeight() / 2 - image.getHeight() / 2, null);
g2d.drawImage(image, (int)(x-image.getWidth()*scale/2), (int)(y-image.getHeight()*scale/2), (int)(image.getWidth()*scale), (int)(image.getHeight()*scale), null);
g.dispose();
}
Back to the matter at hand, how can i work out the maximum x and y size of an image during rotation so I can compensate with my buffered images size?
If you have a basically rectangular image which is rotated around its center, the maximum width and height during rotation will be when a diagonal of the image rectangle is horizontal or vertical. This diagonal distance could be computed with the Pythagorean Theorem and used for the width and height of the BufferedImage.
int size = (int) Math.sqrt((img.getWidth() * img.getWidth()) + (img.getHeight() * img.getHeight()));
BufferedImage image = new BufferedImage(size, size, 2);
// The rest of your code as before
how can i work out the maximum x and y size of an image during rotation so I can compensate with my buffered images size?
double sin = Math.abs(Math.sin(angle));
double cos = Math.abs(Math.cos(angle));
int w = image.getWidth();
int h = image.getHeight();
int neww = (int)Math.floor(w*cos+h*sin);
int newh = (int)Math.floor(h*cos+w*sin);
The above code was taken from this example: Java(SWING) working with Rotation
An alternative is to rotate the actual Graphics object, draw the image, and restore the rotation:
AffineTransform old = g2d.getTransform();
g2d.rotate(Math.toRadians(angle), x + image.getWidth() / 2, y + image.getWidth() / 2);
g2d.drawImage(image, x, y, null);
g2d.setTransform(old);
Let's consider width being the width of the original image, height its original height and angle the rotation angle value in radians.
According to my calculations, the size of the rotated image is something like this:
rotatedWidth = Math.cos(angle) * width + Math.sin(angle) * height;
rotatedHeight = Math.sin(angle) * width + Math.cos(angle) * height;
You may also need to take a look at this thread as well, as it may help.
I'm trying to rotate an image, but it's getting slightly messed up when I'm rotating it, and it looks like it's not rotating it on center. So if I go around it looks like it's being truncated. Is there a better method to get the "center" of the image?
public void RotateImageLeft() {
try {
BufferedImage newImage = new BufferedImage(originalImage.getWidth(), originalImage.getHeight(), originalImage.getType());
AffineTransform tx = new AffineTransform();
tx.rotate(Math.toRadians(-90.0), originalImage.getWidth() / 2, originalImage.getHeight() / 2);
Graphics2D g2 = newImage.createGraphics();
g2.drawImage(originalImage, tx, null);
originalImage = newImage;
this.repaint();
g2.dispose();
} catch (Exception ex) {
ex.toString();
}
//g2d.drawImage(getResImage(), rescale, x, y);
}
For full code disclosure, here's more code. Here's my painComponent overridden method:
public void paintComponent(Graphics g) {
super.paintComponent(g);
resizeImage();
Graphics2D g2d = (Graphics2D) g;
g2d.drawImage(getResImage(), rescale, x, y);
}
Here's the resizeImage() method that gets called:
public void resizeImage() {
Graphics g = getResImage().getGraphics();
g.setColor(Color.WHITE);
g.fillRect(0, 0, getResImage().getWidth(), getResImage().getHeight());
int scaledWidth = (int) ((getOriginalImage().getWidth() * getHeight()
/ getOriginalImage().getHeight()));
if (scaledWidth < getWidth()) {
int leftOffset = getWidth() / 2 - scaledWidth / 2;
int rightOffset = getWidth() / 2 + scaledWidth / 2;
g.drawImage(getOriginalImage(),
leftOffset, 0, rightOffset, getHeight(),
0, 0, getOriginalImage().getWidth(), getOriginalImage().getHeight(),
null);
} else {
int scaledHeight = (getOriginalImage().getHeight() * getWidth())
/ getOriginalImage().getWidth();
int topOffset = getHeight() / 2 - scaledHeight / 2;
int bottomOffset = getHeight() / 2 + scaledHeight / 2;
g.drawImage(getOriginalImage(),
0, topOffset, getWidth(), bottomOffset,
0, 0, getOriginalImage().getWidth(), getOriginalImage().getHeight(),
null);
}
}
I'm using the ResizeImage method since I want any image to fit correctly on my 720/432 panel.
Here's some example pictures.
Pre-rotated
Post-rotated:
New code: (new image is the correct height/width of rotated image, still getting black bars. Screens below.
public void RotateImageLeft() {
try {
BufferedImage newImage = new BufferedImage( originalImage.getHeight(),originalImage.getWidth(), originalImage.getType());
AffineTransform tx = new AffineTransform();
tx.rotate(Math.toRadians(-90.0), newImage.getWidth() / 2, (newImage.getHeight() / 2));
Graphics2D g2 = newImage.createGraphics();
g2.drawImage(originalImage, tx, null);
originalImage = newImage;
this.repaint();
g2.dispose();
} catch (Exception ex) {
ex.toString();
}
}
Post rotate:
From my answer to another similar question
If you're rotating then this will work for 90 degrees.
move image so centered "around" the origin
plain rotate() call with no extra parameters
Move image back into the center remembering that now width = old height and height = old width.
Also remember the affine transform steps work in reverse order.
AffineTransform tx = new AffineTransform();
// last, width = height and height = width
tx.translate(originalImage.getHeight() / 2,originalImage.getWidth() / 2);
tx.rotate(Math.PI / 2);
// first - center image at the origin so rotate works OK
tx.translate(-originalImage.getWidth() / 2,-originalImage.getHeight() / 2);
If you want to rotate an image without cropping you need to add black bars around it first, since a rotated rectangle will always have a bigger bounding box than an axis-aligned one (exception: rotating a square by multiples of 90 degrees).
So what you want to do is do some trigonometric calculations beforehand to decide the maximum Width/Height of the rotated image, and combine that with the original Width/Height. Resize your image (centering it) using those dimensions, rotate it, and then crop it back to the Width/Height of the rotated image.