ofShader should show an error when using an invalid name

[kylemcdonald]

if you have:

uniform float dog;
float cat;

and:

shader.setUniform1f("dog", ofGetElapsedTimef());
shader.setUniform1f("cat", ofGetElapsedTimef());

there is no currently no error printed to the console, and "cat" is mysteriously unchanging while "dog" is fine.

[bakercp]

+1 on this. A pattern like this?

void ofShader::setUniform1i(const char* name, int v1) {
    if(bLoaded) {
                GLint location = getUniformLocation(name);
                if(location != -1) {
                    glUniform1i(location, v1);
                } else {
                    ofLogError("ofShader") << name << " is not a valid uniform.";
                }  
        }  
}

Alternatively, there might be a way to cache uniforms / attributes and check against the cache. PR #1507 might come in handy.