Question

This is my vertex shader code:

attribute vec4 position;
attribute vec4 inputTextureCoordinate;

varying vec2 textureCoordinate;

uniform mat4 modelViewProjMatrix;

void main()
{
    gl_Position = modelViewProjMatrix * position;
textureCoordinate = inputTextureCoordinate.xy;
}

And I update uniform in this code:

glUniformMatrix4fv(uniforms[UNIFORM_MODELVIEWMATRIX], 1, 0, [scaleMatrix getMatrix]);

But when I execute this string last update result(scale) resets:

glUniformMatrix4fv(uniforms[UNIFORM_MODELVIEWMATRIX], 1, 0, [rotationMatrix getMatrix]);

How I can use more than one matrix?

Answer 1

You have to multiply the matrices together. Do this in the CPU and pass the result as the uniform.