inputRange.frag

#version 150

uniform sampler2DRect tex0;

in vec2 texCoordVarying;
out vec4 outputColor;

uniform float minimum;
uniform float maximum;

void main() {

	vec4 inputColor = texture2DRect(tex0, texCoordVarying);
	outputColor = (inputColor - minimum) / (maximum - minimum);
}

inputRange.vert

#version 150

// these are for the programmable pipeline system and are passed in
// by default from OpenFrameworks
uniform mat4 modelViewProjectionMatrix;

in vec4 position;
in vec2 texcoord;

// this is something we're creating for this shader
out vec2 texCoordVarying;

void main()
{
    // here we move the texture coordinates
    texCoordVarying = texcoord;

    // send the vertices to the fragment shader
    gl_Position = modelViewProjectionMatrix * position;
}

source.cpp

					shader.begin();
					shader.setUniform1f("minimum", this->style.rangeMinimum);
					shader.setUniform1f("maximum", this->style.rangeMaximum);

					this->texture.draw(0, 0, width, height);

					shader.end();

access violation if ofShader.cpp: