#include "GfxContext.h"

#include <GL/glew.h>

#include "Batch2D.h"

GfxContext::GfxContext(const GfxContext* parent, Viewport& viewport, Batch2D* g2d)
    : parent(parent), viewport(viewport), g2d(g2d) {
}

GfxContext::~GfxContext() {
    while (scissorsCount--) {
        Window::popScissor();
    }

    if (parent == nullptr)
        return;
        
    if (depthMask_ != parent->depthMask_) {
        glDepthMask(parent->depthMask_);
    }
    if (depthTest_ != parent->depthTest_) {
        if (depthTest_) glDisable(GL_DEPTH_TEST);
        else glEnable(GL_DEPTH_TEST);
    }
    if (cullFace_ != parent->cullFace_) {
        if (cullFace_) glDisable(GL_CULL_FACE);
        else glEnable(GL_CULL_FACE);
    }
    if (blendMode_ != parent->blendMode_) {
        Window::setBlendMode(parent->blendMode_);
    }
}

const Viewport& GfxContext::getViewport() const {
    return viewport;
}

Batch2D* GfxContext::getBatch2D() const {
    return g2d;
}

GfxContext GfxContext::sub() const {
    auto ctx = GfxContext(this, viewport, g2d);
    ctx.depthTest_ = depthTest_;
    ctx.cullFace_ = cullFace_;
    return ctx;
}

void GfxContext::depthMask(bool flag) {
    if (depthMask_ == flag)
        return;
    depthMask_ = flag;
    glDepthMask(GL_FALSE + flag);
}

void GfxContext::depthTest(bool flag) {
    if (depthTest_ == flag)
        return;
    depthTest_ = flag;
    if (flag) {
        glEnable(GL_DEPTH_TEST);
    } else {
        glDisable(GL_DEPTH_TEST);
    }
}

void GfxContext::cullFace(bool flag) {
    if (cullFace_ == flag)
        return;
    cullFace_ = flag;
    if (flag) {
        glEnable(GL_CULL_FACE);
    } else {
        glDisable(GL_CULL_FACE);
    }
}

void GfxContext::blendMode(blendmode mode) {
    if (blendMode_ == mode)
        return;
    blendMode_ = mode;
    Window::setBlendMode(mode);
}

void GfxContext::scissors(glm::vec4 area) {
    Window::pushScissor(area);
    scissorsCount++;
}