I have a simple question for which I do not seem to find the answer to.
I want to create a cube with a 16x16 pixel texture. I can load the texture with the asset manager. The material has a texture with contains an image which contains a byte buffer.
I want to draw my own texture in real time so I need a way to write in the image or the byte buffer of the image. So I can create my own textures from data in the game.
I need some type of method:
image.setPixelColor (int x, int y, Color color)
What is the best and most efficient way to do that?
Example code:
[java]
int width = 16;
int height = 16;
ByteBuffer buffer = BufferUtils.createByteBuffer(width * height * 4);
//(not sure if this is correct)
Image image = new Image(Format.BGR8 , width, height, buffer) ;
// Method to set the color of a pixel of the image
// NEED HELP HERE
texture.setImage(image);
texture.setMagFilter(Texture.MagFilter.Nearest);
material.setTexture("m_DiffuseMap", texture);
[/java]
You can use BufferUtils.createByteBuffer(data) instead of creating an empty buffer.
The format of the data would either be “r,g,b,r,g,b…”, or with 4 values per pixel if you use alpha.
If you want to specify the color of a specific pixel you would replace its values in the buffer and use image.setData(buffer);
You can find the position of the pixel in the buffer with (x + y * imageWidth) * 3 (or * 4)
Yeah, i got it to work.
For anyone who is interested I wrote a helper class
You can paint the texture by using setPixel(int x, int y, Color color)
Or setBackground(Color color)
And you get the new texture bij getTexture();
Like:
[java]
testMaterial = new Material(assetManager,"Common/MatDefs/Light/Lighting.j3md");
PaintebleTexture paint = new PaintebleTexture(16,16);
paint.setBackground(new Color(0,0,0,0));
paint.setPixel(10, 10, new Color(0,0,255,255));
testMaterial.setTexture("m_DiffuseMap", paint.getTexture());
testMaterial.setFloat("m_Shininess", 128f); // [0,128]
testMaterial.getAdditionalRenderState().setBlendMode(BlendMode.Alpha);
item.setMaterial(testMaterial);
[/java]
The paintable texture class:
[java]
import java.awt.Color;
import java.nio.ByteBuffer;
import com.jme3.texture.Image;
import com.jme3.texture.Texture;
import com.jme3.texture.Image.Format;
import com.jme3.texture.Texture2D;
import com.jme3.util.BufferUtils;
public class PaintebleTexture {
protected byte[] data;
protected Image image;
protected Texture2D texture;
int width;
int height;
public PaintebleTexture(int width, int height) {
this.width = width;
this.height = height;
// create black image
data = new byte[width * height * 4];
setBackground (new Color(0,0,0,255));
// set data to texture
ByteBuffer buffer = BufferUtils.createByteBuffer(data);
image = new Image(Format.RGBA8, width, height, buffer);
texture = new Texture2D(image);
texture.setMagFilter(Texture.MagFilter.Nearest);
}
public Texture getTexture() {
ByteBuffer buffer = BufferUtils.createByteBuffer(data);
image.setData(buffer);
return texture;
}
public void setPixel(int x, int y, Color color) {
int i = (x + y * width) * 4;
data = (byte) color.getRed(); // r
data = (byte) color.getGreen(); // g
data = (byte) color.getBlue(); // b
data = (byte) color.getAlpha(); // a
}
public void setBackground(Color color) {
for (int i = 0; i < width * height * 4; i += 4) {
data = (byte) color.getRed(); // r
data = (byte) color.getGreen(); // g
data = (byte) color.getBlue(); // b
data = (byte) color.getAlpha(); // a
}
}
public void setMagFilter(MagFilter filter) {
texture.setMagFilter(filter);
}
}
[/java]
Cool, I suggest adding the class here so it doesnt get buried in the forums 
Hi, I know this post is 3 years old. I tried this method today and its not working anymore. I changed the Color to ColorRGBA class and hoped thats it. Any suggestions whats wrong or missing to get this work with the current version of jme?