Clearing the canvas with J2ME - java-me

I'm trying to create a program that shows two images at random locations and changes them every second. My problem however is when the image is redrawn I can still see the image in the previous position.
I'm using WTK 2.52 if that's relevant.
public void run()
{
while(true)
{
dVert = rand.nextInt(136);
dHorz = rand.nextInt(120);
rVert = 136 + rand.nextInt(136);
rHorz = 120 + rand.nextInt(120);
try
{
Thread.sleep(1000);
}
catch (InterruptedException e)
{
System.out.println("Error");
}
repaint();
}
}
public void paint(Graphics g)
{
int width = this.getWidth() / 2;
int height = this.getHeight() / 2;
g.drawImage(imgR, rVert, rHorz, g.TOP | g.LEFT);
g.drawImage(imgD,dVert,dHorz,g.TOP | g.LEFT);
//g.drawString(disp, width, 50, Graphics.TOP | Graphics.HCENTER);
//g.drawString(centerMsg,width, height, Graphics.TOP | Graphics.HCENTER);
System.out.println(width);
System.out.println(height);
}
Complete code

You clear the canvas like this:
g.setColor(0x000000); // Whatever color you wish to clear with
g.setClip(0,0,getWidth(),getHeight());
g.fillRect(0,0,getWidth(),getHeight());
So just insert those lines before drawing the images.

Related

Drawing Tool with Processing

I am trying to create a little drawing tool with processing. The final drawing should be exportable as a .svg file – so i thought this to be pretty easy… but actually it isnt…
I put the background function into setup – to be able to draw – the safed svg file unfortunately only contains a single frame – and not the whole drawing. :-(
What am I missing – how could I achieve that! I would be thankful for any kind of help!
This is my code so far:
import processing.svg.*;
boolean record;
void setup () {
size(1080, 1080);
background(255);
}
void draw() {
if (record) {
beginRecord(SVG, "frame-####.svg");
}
fill(255);
strokeWeight(1);
ellipse(mouseX, mouseY, 100, 100);
if (record) {
endRecord();
record = false;
}
}
void mousePressed() {
record = true;
}
Tried different things in organizing the code lines in different orders – but could not manage it…
Thank you!
That's because you're creating an image every time you beginRecord and endRecord. If you want to save the image as you see it, you can use save(fileName.png) instead. Here's a code snippet to demonstrate:
void setup() {
size(800, 600);
background(255);
fill(255);
strokeWeight(1);
}
void draw() {
ellipse(mouseX, mouseY, 100, 100);
}
void mousePressed() {
save("myImage.png");
}
If, on the other hand, you really want to use beginRecord, know that it'll save everything you draw between beginRecord and endRecord. You could programatically create an image file this way, as an example, but you cannot just add snapshots to an existing image (which is why you only see "one frame" with your current code). Every time you begin recording, you create a new image. I'm not especially familiar with this method, but one obvious way to do things would be to "save" whatever the user is doing and reproduce those instructions to save them. Here's an example which does this (it saves when you right-click, and I also took the liberty of drawing only when the left mouse button is down):
import processing.svg.*;
boolean record;
ArrayList<PVector> positionsList;
void setup() {
size(800, 600);
positionsList = new ArrayList<PVector>();
}
void draw() {
background(255);
fill(255);
strokeWeight(1);
for (PVector p : positionsList) {
ellipse(p.x, p.y, 100, 100);
}
ellipse(mouseX, mouseY, 100, 100);
if (record) {
positionsList.add(new PVector(mouseX, mouseY));
}
}
void mousePressed() {
record = mouseButton == LEFT;
if (mouseButton == RIGHT) {
beginRecord(SVG, "frame.svg");
fill(255);
strokeWeight(1);
for (PVector p : positionsList) {
ellipse(p.x, p.y, 100, 100);
}
endRecord();
}
}
void mouseReleased() {
record = false;
}
While drawing:
The file (as a png here but it was saved as a svg on my computer):
Hope it helps. Have fun!
import processing.pdf.*;
PShape shape;
void setup () {
size(1080, 1080);
beginRecord(PDF, "drawing.pdf");
shape = loadShape("shape.svg");
shapeMode(CENTER);
background(0,255,0);
}
void draw() {
shape.disableStyle();
fill(255);
strokeWeight(10);
shape(shape, mouseX, mouseY, 200, 200);
}
void keyPressed() {
if (key == 's') {
endRecord();
exit();
}
}

LibGDX draws dots instead of lines

I would like to implement some kind of eraser,so in my render method I make the upper layer transparent.
#Override
public void render () {
cam.update();
Gdx.gl.glClearColor(1, 1, 1,1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
if (Gdx.input.isTouched()) {
pos.set(Gdx.input.getX(), Gdx.input.getY(), 0);
pixmap.setColor(new Color(1, 1, 1, 0.5f)); //transparency
pixmap.fillCircle((int)pos.x, (int)pos.y, 10);
}
texture3.draw(pixmap, 0, 0);
batch.begin();
batch.draw(texture, 0, 0);
batch.draw(texture3, 0, 0);
batch.end();
}
But I got points when make swipes. It requires to do very slow speed to make lines instead of dots.
So I expect continuous line instead of dots.
Can you advice something please?
Dots instead of line
This is caused because of the frequency at which the input state is updated, the solution here would be to manually calculate the missing points needed to make a line, you could do this with a linear interpolation between each pair of dots, additionally you could calculate how many extra dots are necessary depending on how far is the newest dot from the previous one, in my example I use an arbitrary number of extra dots (20) like so:
public class TestDraw extends Game {
private Pixmap pixmap;
private Texture texture;
private SpriteBatch batch;
private Vector2 lastPos;
#Override
public void create() {
pixmap = new Pixmap(1000, 1000, Pixmap.Format.RGBA8888);
texture = new Texture(pixmap);
batch = new SpriteBatch();
lastPos = new Vector2();
}
#Override
public void render() {
Gdx.gl.glClearColor(0, 0, 0, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
if (Gdx.input.isTouched()) {
pixmap.setColor(new Color(1, 1, 1, 0.5f)); //transparency
int newX = Gdx.input.getX();
int newY = Gdx.input.getY();
pixmap.setColor(Color.RED);
pixmap.fillCircle(newX, newY, 10);
// If the distance is too far, fill with extra dots
if (lastPos.dst(newX, newY) > 10) { // Here far is 10, you can adjust as needed
int extraDots = 20; // How many extra dots to draw a line, I use 20, adjust as needed or calculate according to distance (for example lastPos.dst(newX,newY) * 5)
for (int i = 0; i < extraDots; i++) {
float progress = (1f / extraDots) * i;
int dotX = (int) MathUtils.lerp(lastPos.x, newX, progress);
int dotY = (int) MathUtils.lerp(lastPos.y, newY, progress);
pixmap.setColor(Color.BLUE);
pixmap.fillCircle(dotX, dotY, 10);
}
}
// Store last position for next render() call
lastPos.set(newX, newY);
}
texture.draw(pixmap, 0, 0);
batch.begin();
batch.draw(texture, 0, 0);
batch.end();
}
}
Adecuate to your code as needed, I didn't know what was texture3 so I didn't include in my example
Also another option which I don't like too much because of rendering and storage cost is using a Polygon to draw the lines.

Draw Graphics on bitmap

I try to use mouse up and mouse down to draw rectangles on bitmaps. But the problem is that the rectangle always delay one event. For example, I try to draw a rectangle (0,0,50,50) in the first time but there is no rectangle drawing on bitmap. I continues drawing a rect (50,50,100,100) but a rect (0,0,50,50) created (not be the rect (50,50,100,100). If I keep to draw next rects, it always delay like that. Please help me!
This is my code:
Rectangle rect = new Rectangle(0, 0, 0, 0);
int Xmouse;
int Ymouse;
public Form1()
{
InitializeComponent();
pictureBox1.Paint += new PaintEventHandler(pictureBox1_Paint);
this.DoubleBuffered = true;
}
private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
{
Xmouse = e.X;
Ymouse = e.Y;
drawOK = true;
}
private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
{
if (drawOK)
{
drawOK = false;
rect = new Rectangle(Xmouse * 3676 / 800, Ymouse * 3676 / 800, (e.X - Xmouse) * 3676 / 800, (e.Y - Ymouse) * 3676 / 800);
pictureBox1.Invalidate();
}
}
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
using (var g = Graphics.FromImage(pictureBox1.Image))
{
using (Pen myPen = new Pen(Color.Black, 6))
{
g.DrawRectangle(myPen, rect);
}
}
}
Try moving your draw method outside of paint into a different sub and call that sub manually from mouse up:
Rectangle rect = new Rectangle(0, 0, 0, 0);
int Xmouse;
int Ymouse;
bool drawOK;
private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
{
Xmouse = e.X;
Ymouse = e.Y;
Console.WriteLine("MouseDown({0},{1})", e.X, e.Y);
drawOK = true;
}
private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
{
if (drawOK)
{
drawOK = false;
Console.WriteLine("MouseUp({0},{1})", e.X, e.Y);
rect = new Rectangle(Xmouse , Ymouse , (e.X - Xmouse) , (e.Y - Ymouse) );
DrawRect();
pictureBox1.Invalidate();
}
}
private void DrawRect()
{
Console.WriteLine("drawing {0}", rect);
using (var g = Graphics.FromImage(pictureBox1.Image))
{
using (Pen myPen = new Pen(Color.Black, 6))
{
g.DrawRectangle(myPen, rect);
}
}
}
private void ClearPic()
{
using (var g = Graphics.FromImage(pictureBox1.Image))
{
using (Brush myPen = Brushes.White)
{
g.Clear(Color.White);
}
}
}
private void Form1_Load(object sender, EventArgs e)
{
Image bmp = new Bitmap(pictureBox1.Width, pictureBox1.Height);
pictureBox1.Image = bmp;
ClearPic();
pictureBox1.Paint += new PaintEventHandler(pictureBox1_Paint);
pictureBox1.MouseDown += pictureBox1_MouseDown;
pictureBox1.MouseUp += pictureBox1_MouseUp;
}

Crop area selection control(like photoshop's) in c# windows form

how to develop a crop selection control like photoshop's in c# 4.0 in widows form application.
I have a windows form application in c# 4.0 that can crop images. At first you have to draw a rectangle using mouse to select the cropped region.
private Point _pt;
private Point _pt2;
private void picBoxImageProcessing_MouseDown(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
int ix = (int)(e.X / _zoom);
int iy = (int)(e.Y / _zoom);
//reset _pt2
_pt2 = new Point(0, 0);
_pt = new Point(ix, iy);
// pictureBox1.Invalidate();
picBoxImageProcessing.Invalidate();
}
}
private void picBoxImageProcessing_MouseUp(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left && _selecting)
{
_selecting = false;
}
}
private void picBoxImageProcessing_Paint(object sender, PaintEventArgs e)
{
if (_selecting &&_pt.X >= 0 && _pt.Y >= 0 && _pt2.X >= 0 && _pt2.Y >= 0)
{
e.Graphics.DrawRectangle(pen, _pt.X * _zoom, _pt.Y * _zoom,
(_pt2.X - _pt.X) * _zoom, (_pt2.Y - _pt.Y) * _zoom);
}
}
private void picBoxImageProcessing_MouseMove(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
_selecting = true;
int ix = (int)(e.X / _zoom);
int iy = (int)(e.Y / _zoom);
_pt2 = new Point(ix, iy);
// pictureBox1.Invalidate();
picBoxImageProcessing.Invalidate();
}
}
there is no problem to draw the rectangle by mouse dragging. But if i want to change the height or width of the rectangle then I have to draw a new rectangle, that i don't want. I want to change the height and width of the rectangle by modifying the drawn rectangle instead of drawing a new rectangle.
I don’t want to know how to crop. I need to draw a resizable rectangle on the image as we can do in photoshop.
So I need a crop selection control like photoshop's crop control.

Emulated docking the form is sized down, upon removing from dock the form only stays full size when it has focus with a mouse down

Calling module:
private void Indicator_Move(object sender, EventArgs e)
{
Sizer size = new Sizer();
int x = this.Location.X;
int y = this.Location.Y;
int width = this.Width;
int height = this.Height;
var screenWidth = Screen.PrimaryScreen.WorkingArea.Width - 130;
if (x >= screenWidth)
{
size.checkmove(x, y, width, height, this);
}
else if (width == 158 )
{
width = 235;
height = 223;
this.Size = new System.Drawing.Size(width, height);
}
}
Module to Dock and reduce size from Sizer class:
public void checkmove(int movex, int movey,int width, int height, Form mover)
{
var moverheight = mover.Height;
var screenWidth = Screen.PrimaryScreen.WorkingArea.Width - 130;
var screenHeight = Screen.PrimaryScreen.WorkingArea.Height;
var finalx = screenWidth;
if (movex > screenWidth)
{
mover.Size = new System.Drawing.Size(154, 45);
mover.Location = new Point(finalx, screenHeight - 600);
}
}
I actually found a different way to accomplish what I wanted by the double_click event on the form and just moving it out on to the desktop it full size, but I am still curious why it resizes back and forth to full size and reduced size while moving and appearing to flicker and ending up reduced and only showing full size when the mouse button is clicked on form and held down. I'm thinking it has to do with the resizeend call anytime the form is moved. And thanks Joran for the edit.

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