cube-game-plus-plus/client/engine/shader/OverlayShader.cpp

#include "client/engine/shader/OverlayShader.h"
#include "client/engine/Wrapper.h"

OverlayShader::OverlayShader()
{
}

OverlayShader::~OverlayShader()
{
}

bool OverlayShader::init()
{
    program.compile("resources/shader/overlayVertex.vs", "resources/shader/overlayFragment.fs");
    if(!program.isValid())
    {
        return false;
    } 
    
    // get uniform locations
    unifUseTexture = glGetUniformLocation(program.getProgram(), "useTexture");
    unifUseColor = glGetUniformLocation(program.getProgram(), "useColor");
    unifViewMatrix = glGetUniformLocation(program.getProgram(), "viewMatrix");
    unifModelMatrix = glGetUniformLocation(program.getProgram(), "modelMatrix");

    return true;
}

void OverlayShader::preRender()
{
    // bind overlay shader program
    glUseProgram(program.getProgram());
    
    // reset view and model matrix
    view.setToIdentity();
    glUniformMatrix4fv(unifViewMatrix, 1, 0, view.getValues());
    glUniformMatrix4fv(unifModelMatrix, 1, 0, view.getValues());
    
    // set defaults
    setUseTexture(true);
    setUseColor(false);
    
    // reset to default framebuffer
    glBindFramebuffer(GL_FRAMEBUFFER, 0);
    
    // clear color buffer
    glClear(GL_COLOR_BUFFER_BIT);
    
    // depth testing is not needed
    glDisable(GL_DEPTH_TEST);
}

void OverlayShader::setViewMatrix()
{
    view.set(0, 0, (2.0f * Engine::getScale()) / Engine::getWidth());
    view.set(0, 1, 0.0f);
    view.set(0, 2, 0.0f);
    view.set(0, 3, -1.0f);
    
    view.set(1, 0, 0.0f);
    view.set(1, 1, (-2.0f * Engine::getScale()) / Engine::getHeight());
    view.set(1, 2, 0.0f);
    view.set(1, 3, 1.0f);
    
    view.set(2, 0, 0.0f);
    view.set(2, 1, 0.0f);
    view.set(2, 2, (-1.0f * Engine::getScale()) / Engine::getHeight());
    view.set(2, 3, 0.5f);
    
    view.set(3, 0, 0.0f);
    view.set(3, 1, 0.0f);
    view.set(3, 0, 0.0f);
    view.set(3, 3, 1.0f);
    
    glUniformMatrix4fv(unifViewMatrix, 1, 0, view.getValues());
}

void OverlayShader::setModelMatrix(const float* data)
{
    glUniformMatrix4fv(unifModelMatrix, 1, 0, data);
}

void OverlayShader::setUseTexture(bool use)
{
    glUniform1i(unifUseTexture, use);
}

void OverlayShader::setUseColor(bool use)
{
    glUniform1i(unifUseColor, use);
}