Render a dynamic texture to the screen

[cookiedragon234]

Hi

 

I am trying to create a colour picker gui element, which displays the HSV colour space, with the x and y axis representing Saturation and Value, and a separate slider for hue and alpha.

 

Something like this is the goal:

 

This is my code so far:

	final Minecraft mc = Minecraft.getMinecraft();
	final BufferedImage bufferedImage = new BufferedImage(100,100, TYPE_INT_ARGB);
	final DynamicTexture dynamicTexture = new DynamicTexture(bufferedImage);
	ResourceLocation dynamicResource;
	
	private int hue = 1;
	private float alpha = 1;


	@Override
	public void render(Vec2f mousePos)
	{
		for (int x = 0; x < bufferedImage.getWidth(); x++)
		{
			for (int y = 0; y < bufferedImage.getHeight(); y++)
			{
				float xPercent = x / 100;
				float yPercent = y / 100;
				Color c = ColourUtils.hsvToRgb(hue, xPercent, yPercent, alpha);
				bufferedImage.setRGB(x, y, c.getRGB());
			}
		}
		
		GlStateManager.color(1,1,1,1);
		GlStateManager.enableTexture2D();
		bufferedImage.getRGB(0, 0, bufferedImage.getWidth(), bufferedImage.getHeight(), dynamicTexture.getTextureData(), 0, bufferedImage.getWidth());
		dynamicTexture.updateDynamicTexture();
		//mc.getTextureManager().loadTexture(dynamicResource, dynamicTexture);
		dynamicResource = mc.getTextureManager().getDynamicTextureLocation("background", this.dynamicTexture);
		RenderUtils.drawTextureAt((int) position.x, (int) position.y, 100, 100, dynamicResource);
		mc.getTextureManager().deleteTexture(dynamicResource);
    }

Which does not work, it simply displays a white square.

 

Does anyone know how to render a dynamic texture or a buffered image to the screen?

Edited January 5, 2020 by cookiedragon234

[imacatlolol]

Rather than rendering a texture/image, it may be better to use OpenGL to specify four vertices with different colors, then render a square. It should produce the 2D gradient effect you're looking for without having to generate a new texture every frame.

I'm not very experienced with OpenGL, so I'm afraid I can't give an exact workflow for it.

[cookiedragon234]

Im not sure whether that would produce s spectrum allowing a significant amount of colour choices. Also in order to save the users chosen colour, I need to take the colour where they click. With a buffered image I can just do getRgb at the position they clicked, but with your method Im not sure how I would do that.

[Cadiboo]

22 hours ago, cookiedragon234 said:

Im not sure whether that would produce s spectrum allowing a significant amount of colour choices.

It would produce whatever spectrum you want, just in a tiny fraction of the time it would take to do it in Java code (All the work is done on the GPU). Then get the pixel color back out either by calculating the RGB some way or actually sampling the RGB on screen.