OpenGL de プログラミング

#include <iostream>
#include <algorithm>
#include <vector>
#include <gl/glut.h>
#include <lib3ds.h>

char *modelname = "Tree.3DS";

//メッシュ構造体
struct Mesh
{
	unsigned int nIndex;
	std::vector<float> vertex;
	std::vector<float> normal;
	std::vector<unsigned int> index;
	int flag;
};

std::vector<Mesh> eachMesh;

//--- function Object ---//
class CIncrement
{
private:
	unsigned int num;
public:
	CIncrement():num(0){}//コンストラクタ
        
	unsigned int operator()()
	{
		return num++;
	}
};


float scales = 1.f;

//確認用
void draw2()
{
	static int MeshNum = eachMesh.size();
	glBegin(GL_TRIANGLES);
	for(int loop = 0; loop < MeshNum;++loop)
	{
		for(int k = 0; k < eachMesh[loop].vertex.size();k+=9)
		{
			glNormal3fv(&eachMesh[loop].normal[k]);
			glVertex3fv(&eachMesh[loop].vertex[k]);

			glNormal3fv(&eachMesh[loop].normal[k+3]);
			glVertex3fv(&eachMesh[loop].vertex[k+3]);
			
			glNormal3fv(&eachMesh[loop].normal[k+6]);
			glVertex3fv(&eachMesh[loop].vertex[k+6]);
		}
	}
	glEnd();
}

void display()
{
	static int angle = 0;
	static int MeshNum = eachMesh.size();

	glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
	glLoadIdentity();
	gluLookAt(20,30,80,0,0,0,0,1,0);

	glColor3f(0.8,0.8,0.8f);

	glPushMatrix();
	glRotatef(float(angle),0,1,0);//各種位置調整
	glScalef(scales,scales,scales);
	glRotatef(90,-1,0,0);

	//////描画
	glEnableClientState(GL_VERTEX_ARRAY);
	glEnableClientState(GL_NORMAL_ARRAY);
	for(int loop = 0; loop < MeshNum;++loop)
	{       
		if(eachMesh[loop].flag == 1) continue;

		glVertexPointer(3, GL_FLOAT, 0,&eachMesh[loop].vertex[0]);
		glNormalPointer(GL_FLOAT,0,&eachMesh[loop].normal[0]);
		//glDrawArrays(GL_TRIANGLES,0,eachMesh[loop].vertex.size()/3);//確認用
		glDrawElements(GL_TRIANGLES,eachMesh[loop].nIndex, GL_UNSIGNED_INT, &eachMesh[loop].index[0]);
	}
	glDisableClientState(GL_NORMAL_ARRAY);
	glDisableClientState(GL_VERTEX_ARRAY);
	//draw2();//確認用
	glPopMatrix();



	glColor3f(1,1,1);

	glutSwapBuffers();
	if(++angle >= 360) angle = 0;
}


void reshape(int w, int h)
{
	glViewport(0,0,w,h);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluPerspective(30,double(w)/h,0.1,1000);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
}


void idle()
{
	glutPostRedisplay();
}

void specialkey(int key,int x, int y)
{
	switch(key)
	{
	case GLUT_KEY_UP:
		scales *= 2.f;
	break;

	case GLUT_KEY_DOWN:
		scales *= 0.5f;
	break;

	}
}

void init()
{
	glClearColor(1,1,1,1);
	glEnable(GL_DEPTH_TEST);
	glEnable(GL_NORMALIZE);
	glEnable(GL_LIGHT0);
	glEnable(GL_LIGHTING);

	glColorMaterial(GL_FRONT_AND_BACK,GL_AMBIENT_AND_DIFFUSE);
	glEnable(GL_COLOR_MATERIAL);
}

void keyboard(unsigned char key, int x, int y)
{
	switch(key)
	{
	case 'q':
	case '\033':
		exit(0);
	break;
	}
}

void load3dsModel()
{
	Lib3dsFile *m_model; //モデル全体
	Lib3dsMesh *mesh; //メッシュ単位

	//モデル読み込み
	m_model = lib3ds_file_open(modelname);
	if(m_model==NULL)
	{
		std::cerr << "can't Open file\n";
		exit(0);
	}

	eachMesh.resize(m_model->nmeshes);//メッシュ分メモリ確保
	for(int loop = 0; loop < m_model->nmeshes;++loop)
	{
		mesh = m_model->meshes[loop];//mLoop番目のメッシュへのポインタ
		if(mesh->nfaces == 0) {
			eachMesh[loop].flag = 1;
			continue;
		}//メッシュが無い場合はカット

		//法線データの取り出し
		float (*normal)[3] = new float[mesh->nfaces*3][3];
		lib3ds_mesh_calculate_vertex_normals(mesh,&normal[0]);//頂点法線の取り出し

		eachMesh[loop].normal.resize(mesh->nfaces*3*3);//法線用メモリ確保(面の数*3頂点*3座標)
		eachMesh[loop].vertex.resize(mesh->nfaces*3*3);//頂点用メモリ確保(頂点数*3要素)

		//頂点データと法線データをインデックスに合わせて格納
		for(int loopX = 0; loopX < mesh->nfaces;++loopX)
		{
			//1頂点目
			memcpy(&eachMesh[loop].normal[loopX*9],&normal[loopX*3][0],sizeof(float)*3);
			memcpy(&eachMesh[loop].vertex[loopX*9],
					&mesh->vertices[ mesh->faces[loopX].index[0] ][0],sizeof(float)*3);
			//２頂点目
			memcpy(&eachMesh[loop].normal[loopX*9+3],&normal[loopX*3+1][0],sizeof(float)*3);
			memcpy(&eachMesh[loop].vertex[loopX*9+3],
					&mesh->vertices[ mesh->faces[loopX].index[1] ][0],sizeof(float)*3);
			//3頂点目
			memcpy(&eachMesh[loop].normal[loopX*9+6],&normal[loopX*3+2][0],sizeof(float)*3);
			memcpy(&eachMesh[loop].vertex[loopX*9+6],
					&mesh->vertices[ mesh->faces[loopX].index[2] ][0],sizeof(float)*3);
		}

		eachMesh[loop].nIndex = mesh->nfaces * 3;
		eachMesh[loop].index.resize( eachMesh[loop].nIndex );//面の数*3頂点分=総インデックス数

		//インデックスデータの設定(0,1,2,3,4...でOK)
		std::generate(eachMesh[loop].index.begin(),eachMesh[loop].index.end(),CIncrement());

		delete [] normal;

	}

	lib3ds_file_free(m_model);

}


int main(int argc, char *argv[])
{
	glutInit(&argc,argv);
	glutInitDisplayMode(GLUT_RGBA|GLUT_DEPTH|GLUT_DOUBLE);
	glutInitWindowSize(640,480);
	glutCreateWindow("Vertex Normal and Ary");

	glutDisplayFunc(display);
	glutReshapeFunc(reshape);
	glutSpecialFunc(specialkey);
	glutKeyboardFunc(keyboard);
	glutIdleFunc(idle);

	init();
	load3dsModel();

	glutMainLoop();

	return 0;
}