/**
 cameraFrame 移动的公转自转
 
 物体移动：
    物体本身移动
    物体坐标系移动
 
 观察者移动
 
 */

#include "LCDay5.hpp"

#include "GLTools.h"
#include "GLShaderManager.h"
#include "GLFrustum.h"
#include "GLBatch.h"
#include "GLMatrixStack.h"
#include "GLGeometryTransform.h"
#include "StopWatch.h"

#include <math.h>
#include <stdio.h>

#ifdef __APPLE__
#include <glut/glut.h>
#else
#define FREEGLUT_STATIC
#include <GL/glut.h>
#endif


static GLShaderManager        shaderManager;            // 着色器管理器
static GLMatrixStack        modelViewMatrix;        // 模型视图矩阵
static GLMatrixStack        projectionMatrix;        // 投影矩阵
static GLFrustum            viewFrustum;            // 视景体
static GLGeometryTransform    transformPipeline;        // 几何图形变换管道

static GLTriangleBatch        torusBatch;             //大球
static GLTriangleBatch     sphereBatch;            //小球
static GLBatch                floorBatch;          //地板

//角色帧 照相机角色帧
static GLFrame             cameraFrame;

//**4、添加附加随机球
#define NUM_SPHERES 50
static GLFrame spheres[NUM_SPHERES];

static void SetupRC()
{
    //1.初始化
    glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
    shaderManager.InitializeStockShaders();
    
    //2.开启深度测试
    glEnable(GL_DEPTH_TEST);
   
    //3. 设置地板顶点数据
    floorBatch.Begin(GL_LINES, 324);
    for(GLfloat x = -20.0; x <= 20.0f; x+= 0.5) {
        floorBatch.Vertex3f(x, -0.55f, 20.0f);
        floorBatch.Vertex3f(x, -0.55f, -20.0f);
        
        floorBatch.Vertex3f(20.0f, -0.55f, x);
        floorBatch.Vertex3f(-20.0f, -0.55f, x);
    }
    floorBatch.End();
    
    //4.设置大球模型
     gltMakeSphere(torusBatch, 0.4f, 40, 80);
    
    //5. 设置小球球模型
    gltMakeSphere(sphereBatch, 0.1f, 26, 13);
    
    //6. 随机位置放置小球球
    for (int i = 0; i < NUM_SPHERES; i++) {
        
        //y轴不变，X,Z产生随机值
        GLfloat x = ((GLfloat)((rand() % 400) - 200 ) * 0.1f);
        GLfloat z = ((GLfloat)((rand() % 400) - 200 ) * 0.1f);
        
        //在y方向，将球体设置为0.0的位置，这使得它们看起来是飘浮在眼睛的高度
        //对spheres数组中的每一个顶点，设置顶点数据
        spheres[i].SetOrigin(x, 0.0f, z);
    }
}

//进行调用以绘制场景
static void RenderScene(void)
{
    //1.颜色值(地板,大球,小球颜色)
    static GLfloat vFloorColor[] = { 0.0f, 1.0f, 0.0f, 1.0f};
    static GLfloat vTorusColor[] = { 1.0f, 0.0f, 0.0f, 1.0f};
    static GLfloat vSphereColor[] = { 0.0f, 0.0f, 1.0f, 1.0f};
    
    //2.基于时间动画
    static CStopWatch rotTimer;
    float yRot = rotTimer.GetElapsedSeconds() * 60.0f;
    
    //3.清除颜色缓存区和深度缓冲区
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    //4.加入观察者 平移10步(地板,大球,小球,小小球)
    M3DMatrix44f mCamera;
    cameraFrame.GetCameraMatrix(mCamera);
    modelViewMatrix.PushMatrix(mCamera);


    //5.获取光源位置
    M3DVector4f vLightPos = {0.0f,10.0f,5.0f,1.0f};
    
    //6.绘制地面
    shaderManager.UseStockShader(GLT_SHADER_FLAT,
                                 transformPipeline.GetModelViewProjectionMatrix(),
                                 vFloorColor);
    floorBatch.Draw();
    
    //大球默认位置(0,0,0)Z深度(3.0) 正负指的是方向, 数字指的移动距离
    //7.使得大球位置平移(3.0)向屏幕里面  只移动1次
    modelViewMatrix.PushMatrix();
    modelViewMatrix.Translate(0.0f, 0.0f, -3.0f);
    
    //8.压栈(复制栈顶)
    modelViewMatrix.PushMatrix();
   
    //9.大球自转
    modelViewMatrix.Rotate(yRot, 0.0f, 1.0f, 0.0f);
    
    //10.指定合适的着色器(点光源着色器)
    shaderManager.UseStockShader(GLT_SHADER_POINT_LIGHT_DIFF, transformPipeline.GetModelViewMatrix(),
                                 transformPipeline.GetProjectionMatrix(), vLightPos, vTorusColor);
    torusBatch.Draw();
    //11.绘制完毕则Pop
    modelViewMatrix.PopMatrix();
    
 
    //12.画小球
    for (int i = 0; i < NUM_SPHERES; i++) {
        modelViewMatrix.PushMatrix();
        modelViewMatrix.MultMatrix(spheres[i]);
        shaderManager.UseStockShader(GLT_SHADER_POINT_LIGHT_DIFF, transformPipeline.GetModelViewMatrix(),
                                     transformPipeline.GetProjectionMatrix(), vLightPos, vSphereColor);
        sphereBatch.Draw();
        modelViewMatrix.PopMatrix();
        
    }

    //13. 让一个小篮球围绕大球公众自转
    //学员提问: 为什么这里老师没有加PushMatrix/PopMatrix ,是可以加的.但是因为是最后的绘图因为没有不会影响就么有添加. 这边给大家添加一组.
    modelViewMatrix.PushMatrix();
    modelViewMatrix.Rotate(yRot * -2.0f, 0.0f, 1.0f, 0.0f);
    modelViewMatrix.Translate(0.8f, 0.0f, 0.0f);
    shaderManager.UseStockShader(GLT_SHADER_FLAT,transformPipeline.GetModelViewProjectionMatrix(),vSphereColor);
    sphereBatch.Draw();
    modelViewMatrix.PopMatrix();
    
    //移除z轴的平移
    modelViewMatrix.PopMatrix();
    
    //移除观察者矩阵
    modelViewMatrix.PopMatrix();
    
    
    //14.执行缓存区交换
    glutSwapBuffers();
    
    //15
    glutPostRedisplay();
    
  
}

//屏幕更改大小或已初始化
static void ChangeSize(int nWidth, int nHeight)
{
    //1.设置视口
    glViewport(0, 0, nWidth, nHeight);
    
    //2.创建投影矩阵，。
    viewFrustum.SetPerspective(35.0f, float(nWidth)/float(nHeight), 1.0f, 100.0f);
    //viewFrustum.GetProjectionMatrix()  获取viewFrustum投影矩阵
    //并将其加载到投影矩阵堆栈上
    projectionMatrix.LoadMatrix(viewFrustum.GetProjectionMatrix());
    
    
    //3.设置变换管道以使用两个矩阵堆栈（变换矩阵modelViewMatrix ，投影矩阵projectionMatrix）
    //初始化GLGeometryTransform 的实例transformPipeline.通过将它的内部指针设置为模型视图矩阵堆栈 和 投影矩阵堆栈实例，来完成初始化
    //当然这个操作也可以在SetupRC 函数中完成，但是在窗口大小改变时或者窗口创建时设置它们并没有坏处。而且这样可以一次性完成矩阵和管线的设置。
    transformPipeline.SetMatrixStacks(modelViewMatrix, projectionMatrix);
}



static void SpeacialKeys(int key,int x,int y){
    
    //移动步长
    float linear = 0.1f;
    //旋转度数
    float angular = float(m3dDegToRad(5.0f));
    
    if (key == GLUT_KEY_UP) {
        
        //MoveForward 平移
        cameraFrame.MoveForward(linear);
    }
    if (key == GLUT_KEY_DOWN) {
        cameraFrame.MoveForward(-linear);
    }
    
    if (key == GLUT_KEY_LEFT) {
        //RotateWorld 旋转
        cameraFrame.RotateWorld(angular, 0.0f, 1.0f, 0.0f);
    }
    
    if (key == GLUT_KEY_RIGHT) {
        cameraFrame.RotateWorld(-angular, 0.0f, 1.0f, 0.0f);
    }
    

}

int fifth(int argc, char* argv[])
{
    gltSetWorkingDirectory(argv[0]);
    
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
    glutInitWindowSize(800,600);
    
    glutCreateWindow("OpenGL SphereWorld");
    
    glutReshapeFunc(ChangeSize);
    glutDisplayFunc(RenderScene);
    glutSpecialFunc(SpeacialKeys);
    
    GLenum err = glewInit();
    if (GLEW_OK != err) {
        fprintf(stderr, "GLEW Error: %s\n", glewGetErrorString(err));
        return 1;
    }
    
    
    SetupRC();
    glutMainLoop();
    return 0;
}