Change sprite color into white

Question

I'm trying to change the color of a sprite (which is red and gray), in white color.

sprite.setColor(1, 1, 1, 1);

But nothing is happening.

How can I change all the sprite colors in white?

Answer 1

If you want to change the color of all the shapes in the sprite to white then the only way you can do this is to use a pixel shader and set all the fragments that they are not black(i assume black renders as transperant in your game) to white. Something like that:

varying vec4 v_color;
varying vec2 v_texCoords;
uniform sampler2D u_texture;
void main() {
    vec4 color=v_color * texture2D(u_texture, v_texCoords);

    if(color.r!=0 && color.g!=0 && color.b!=0){
        gl_FragColor=vec4(1,1,1,1);
    }
    else{
        gl_FragColor=color;
    }
}

If you are unfortunate and you use opengl 1.0(fixed pipeline), I suggest you to switch to gles 2.0 now that you are a beginer.Fixed pipeline is from the 90' , we are at 2013!

The code:

Initialize:

  ShaderProgram.pedantic = false;

  ShaderProgram defaultShader=SpriteBatch.createDefaultShader();

  ShaderProgram shaderWhiteTexture=new ShaderProgram(Gdx.files.internal("vertexShader.vs").readString(),Gdx.files.internal("fragShader.fs").readString());

Render:

//Render the textures with the normal colors 
spriteBatch.begin();
spriteBatch.draw(sprite1,sprite2,sprite3...);//or whatever code u use to render them
spriteBatch.end();

//Render the textures with the shader
spriteBatch.setShader(shaderWhiteTexture);
spriteBatch.begin();
spriteBatch.draw(sprite4,sprite5,sprite6...);//or whatever code u use to render them
spriteBatch.end();
spriteBatch.setShader(defaultShader);

Shaders:

//vertexShader.vs:
attribute highp vec4 a_position;
attribute highp vec4 a_color;
attribute highp vec2 a_texCoord0;
uniform mat4 u_projTrans;

varying highp vec4 v_color;
varying highp vec2 v_texCoords;

void main() {
    v_color = a_color;
    v_texCoords = a_texCoord0;
    gl_Position = u_projTrans * a_position ;
}

//fragShader.fs:
varying highp vec4 v_color;
varying highp vec2 v_texCoords;
uniform sampler2D u_texture;
void main() {

    gl_FragColor = vec4(0.0);

    highp vec4 color = texture2D(u_texture, v_texCoords);

    if(color.a > 0.0) {
       gl_FragColor = vec4(1.0,0,0,1.0);
}

}

EDITED BY QUESTION OWNER : Now works with transparent texture

What have been added ? :

1 . the highp precision to variables
2 . the fragmentShader file Main() fonction edited