// GeoTest.cpp
// OpenGL SuperBible
// Demonstrates OpenGL Backface culling, depth testing, and polygon mode
// Program by Richard S. Wright Jr.
#include <GLTools.h>	// OpenGL toolkit
#include <GLMatrixStack.h>
#include <GLFrame.h>
#include <GLFrustum.h>
#include <GLGeometryTransform.h>

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


GLFrame             viewFrame;
GLFrustum           viewFrustum;
GLTriangleBatch     torusBatch;
GLMatrixStack       modelViewMatix;
GLMatrixStack       projectionMatrix;
GLGeometryTransform transformPipeline;
GLShaderManager     shaderManager;

// Flags for effects
int iCull = 0;
int iDepth = 0;

///////////////////////////////////////////////////////////////////////////////
// Reset flags as appropriate in response to menu selections
void ProcessMenu(int value)
	{
	switch(value)
		{
		case 1:
			iDepth = !iDepth;
			break;

		case 2:
			iCull = !iCull;
			break;

        case 3:
            glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
            break;

        case 4:
            glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
            break;
                
        case 5:
            glPolygonMode(GL_FRONT_AND_BACK, GL_POINT);
            break;
		}

	glutPostRedisplay();
	}


// Called to draw scene
void RenderScene(void)
	{
	// Clear the window and the depth buffer
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	// Turn culling on if flag is set
	if(iCull)
		glEnable(GL_CULL_FACE);
	else
		glDisable(GL_CULL_FACE);

	// Enable depth testing if flag is set
	if(iDepth)
		glEnable(GL_DEPTH_TEST);
	else
		glDisable(GL_DEPTH_TEST);

		
    modelViewMatix.PushMatrix(viewFrame);
            
    GLfloat vRed[] = { 1.0f, 0.0f, 0.0f, 1.0f };
    //shaderManager.UseStockShader(GLT_SHADER_FLAT, transformPipeline.GetModelViewProjectionMatrix(), vRed);
    shaderManager.UseStockShader(GLT_SHADER_DEFAULT_LIGHT, transformPipeline.GetModelViewMatrix(), transformPipeline.GetProjectionMatrix(), vRed);
    

    torusBatch.Draw();

    modelViewMatix.PopMatrix();


    glutSwapBuffers();
	}

// This function does any needed initialization on the rendering
// context. 
void SetupRC()
	{
	// Black background
	glClearColor(0.3f, 0.3f, 0.3f, 1.0f );

    shaderManager.InitializeStockShaders();
    viewFrame.MoveForward(7.0f);

    // Make the torus
    gltMakeTorus(torusBatch, 1.0f, 0.3f, 52, 26);

    glPointSize(4.0f);
	}

void SpecialKeys(int key, int x, int y)
	{
	if(key == GLUT_KEY_UP)
		viewFrame.RotateWorld(m3dDegToRad(-5.0), 1.0f, 0.0f, 0.0f);

	if(key == GLUT_KEY_DOWN)
		viewFrame.RotateWorld(m3dDegToRad(5.0), 1.0f, 0.0f, 0.0f);
        
	if(key == GLUT_KEY_LEFT)
		viewFrame.RotateWorld(m3dDegToRad(-5.0), 0.0f, 1.0f, 0.0f);
        
	if(key == GLUT_KEY_RIGHT)
		viewFrame.RotateWorld(m3dDegToRad(5.0), 0.0f, 1.0f, 0.0f);

	// Refresh the Window
	glutPostRedisplay();
	}


void ChangeSize(int w, int h)
	{
	// Prevent a divide by zero
	if(h == 0)
		h = 1;

	// Set Viewport to window dimensions
    glViewport(0, 0, w, h);

    viewFrustum.SetPerspective(35.0f, float(w)/float(h), 1.0f, 100.0f);
    
    projectionMatrix.LoadMatrix(viewFrustum.GetProjectionMatrix());
    transformPipeline.SetMatrixStacks(modelViewMatix, projectionMatrix);
	}

///////////////////////////////////////////////////////////////////////////////
// Main entry point for GLUT based programs
int main(int argc, char* argv[])
    {
	gltSetWorkingDirectory(argv[0]);
	
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH | GLUT_STENCIL);
	glutInitWindowSize(800, 600);
	glutCreateWindow("Geometry Test Program");
    glutReshapeFunc(ChangeSize);
    glutSpecialFunc(SpecialKeys);
    glutDisplayFunc(RenderScene);

    // Create the Menu
    glutCreateMenu(ProcessMenu);
    glutAddMenuEntry("Toggle depth test",1);
    glutAddMenuEntry("Toggle cull backface",2);
    glutAddMenuEntry("Set Fill Mode", 3);
    glutAddMenuEntry("Set Line Mode", 4);
    glutAddMenuEntry("Set Point Mode", 5);
    
    glutAttachMenu(GLUT_RIGHT_BUTTON);
        
    
	GLenum err = glewInit();
	if (GLEW_OK != err) {
		fprintf(stderr, "GLEW Error: %s\n", glewGetErrorString(err));
		return 1;
    }
	
	SetupRC();
    
	glutMainLoop();
	return 0;
    }