[LibGDX] Make Texture/Sprite black and white?

[Slyntax]

Is there any way to remove the color from a Texture in LibGDX and be left with a grayscaled image?

[davedes]

If you don't need it done in real-time, then you're better off using Photoshop or GIMP to save two copies of your image.

If you need it in real-time or need to process a lot of sprites, using shaders is the ideal solution.

Shader Lesson 3: Grayscale and other effects
Code example

Another solution is to process the Pixmap before uploading it to a Texture:
Pixmaps & Textures

[Slyntax]

Yeah looking through the LWJGL Shader Tutorial now and that looks like the better solution.

Thanks a million for the code example as well. That will save me a ton of time lol.

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[relminator]

Depending on what version of GL you're using you can use glTexEnvf() + glTexEnvfv() + glColor() to draw pure white sprites. Or its shader counterpart.

[Slyntax]

If you don't need it done in real-time, then you're better off using Photoshop or GIMP to save two copies of your image.

If you need it in real-time or need to process a lot of sprites, using shaders is the ideal solution.

Shader Lesson 3: Grayscale and other effects
Code example

Another solution is to process the Pixmap before uploading it to a Texture:
Pixmaps & Textures

Yeah it needs to be done in real time. So I'm going with Shaders. I found settings for a default shader as well.

My problem right now is that when I apply the grayscaled shader nothing renders... but when I set the shader to the default it renders everything after it fine.

I'm, obviously, very new to shaders so is there anything simple that I might be missing?

Note: I copied VERT and FRAG entirely from the code example.

This is what takes place in my render...

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batch.setShader(shader); time += Gdx.graphics.getDeltaTime();           grayscale = (float)Math.sin(time)/2f+0.5f;         shader.begin(); shader.setUniformf("grayscale", grayscale); shader.end(); sprite.draw(batch); batch.setShader(default_shader) ...

[Slyntax]

Figured it out.

Didn't need to use

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time += Gdx.graphics.getDeltaTime();           grayscale = (float)Math.sin(time)/2f+0.5f;         shader.begin(); shader.setUniformf("grayscale", grayscale); shader.end();

It's now just...

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batch.setShader(shader); sprite.draw(batch); batch.setShader(default_shader)

And works as expected.

[davedes]

The "grayscale" uniform allows you to change the strength of the effect; i.e. in case you want some things grayscale and some things in color.

Read through lessons 1 - 3 for more info on using uniforms.

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//start rendering your batch batch.begin(); //enable grayscale shader.setUniformf("grayscale", 1.0f); //draw your grayscale entities for (...)    batch.draw(...); //now FLUSH the batch; same as using end() + begin() batch.flush(); //now disable the grayscale effect shader.setUniformf("grayscale", 0.0f); //... render your color entities ...// //finish rendering shader.end();

This only affects the proceeding batch. So your code needs to look like this: