0

I like to draw a rectangle with the OpenGL ES 1.0 function "drawArray" and over this rectangele I want to draw a texture with alpha. (A Hud element and the drawArray rectangle shows the "fill state" of that element).

Basically it works but the texture with alpha which I draw over the drawArray rectangle is affected by the color of the rectangle. the drawArray draws a blue rectangle and the texture shows after drawing also blueish.

Here the functions I'm using:

SOLVED -- See "START SOLUTION"

private void bagFillState(GL10 gl) {
    // fill state background
    gl.glMatrixMode(GL10.GL_MODELVIEW);
    gl.glLoadIdentity();
    gl.glPushMatrix();
    gl.glScalef(0.25f, 0.25f, 0f);
    gl.glTranslatef(0.0f, 3.0f, 0f);

    gl.glDisable(GL10.GL_TEXTURE_2D);

    // Draw background
    gl.glVertexPointer(2, GL10.GL_FLOAT, 0, _vertsGUIFillBuffer);
    gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
    gl.glColorPointer(4, GL10.GL_FLOAT, 0, _colorGUIFillBuffer);
    gl.glEnableClientState(GL10.GL_COLOR_ARRAY);
    gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 4);

    // START SOLUTION - Add the following Line
    gl.glDisableClientState(GL10.GL_COLOR_ARRAY);
    // END SOLTUTION

    gl.glEnable(GL10.GL_TEXTURE_2D);

    gl.glPopMatrix();
    gl.glLoadIdentity();        
}

The method who draws the texture over it:

private void bagChoosing(GL10 gl) {
    // HUD
    gl.glMatrixMode(GL10.GL_MODELVIEW);
    gl.glLoadIdentity();
    gl.glPushMatrix();
    gl.glScalef(0.25f, 1.0f, 1f);
    gl.glTranslatef(0.0f, 0.0f, 0f);

    gl.glMatrixMode(GL10.GL_TEXTURE);
    gl.glLoadIdentity();

    _gui.draw(gl);
    gl.glPopMatrix();
    gl.glLoadIdentity();
}

public void onDrawFrame(GL10 gl) {
    gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT | GL10.GL_STENCIL_BUFFER_BIT);

    background1(gl);

    movePlayer1(gl);
    bagFillState(gl);
    bagChoosing(gl);

    // All other game drawing will be called here
    gl.glEnable(GL10.GL_BLEND);
    gl.glBlendFunc(GL10.GL_SRC_ALPHA, GL10.GL_ONE_MINUS_SRC_ALPHA);
}

Is there something special I have to do while loading the texture or drawing with "drawArray", so the drawArray rectangle doesn't affect the textures color? Thanks for any hint or link.

Bruno Bieri
  • 9,724
  • 11
  • 63
  • 92

1 Answers1

1

Did you reset the color pointer before drawing the texture, or disable the GL_COLOR_ARRAY client state?

It sounds like your blue color is still enabled, which is modulating the sampled texture.

Please put up the full drawing code for the texture if this doesn't answer your question, as well as linking to an image of the problem.

Tim
  • 35,413
  • 11
  • 95
  • 121