一 数据类型和简单绘制

标签：opengl

typedef struct {
    GLfloat x;
    GLfloat y;
    GLfloat z;
} Vertex3D;


static inline Vertex3D Vertex3DMake(CGFloat inX, CGFloat inY, CGFloat inZ)
{
    Vertex3D ret;
    ret.x = inX;
    ret.y = inY;
    ret.z = inZ;
    return ret;
}


static inline GLfloat Vertex3DCalculateDistanceBetweenVertices (Vertex3D first, Vertex3D second)
{
    GLfloat deltaX = second.x - first.x;
    GLfloat deltaY = second.y - first.y;
    GLfloat deltaZ = second.z - first.z;
    return sqrtf(deltaX*deltaX + deltaY*deltaY + deltaZ*deltaZ );
};

Vertex3D vertex;
vertex.x = 10.0;
vertex.y = 23.75;
vertex.z = -12.532;

typedef struct {
    Vertex3D v1;
    Vertex3D v2;
    Vertex3D v3;
} Triangle3D;


static inline Triangle3D Triangle3DMake(Vertex3D v1, Vertex3D v2, Vertex3D v3);

    // 创建一个三角形
    Vertex3D vertex1 = Vertex3DMake(0.0, 1.0, -3.0);
    Vertex3D vertex2 = Vertex3DMake(1.0, 0.0, -3.0);
    Vertex3D vertex3 = Vertex3DMake(-1.0, 0.0, -3.0);
    Triangle3D triangle = Triangle3DMake(vertex1, vertex2, vertex3);


    // 绘制三角形
    glLoadIdentity();// 加载单位矩阵,清除虚拟世界中的一切旋转，移动或其他变化并将观察者置于原点
    glClearColor(0.7, 0.7, 0.7, 1.0);// 设置背景色的RGBA
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);// 通知OpenGL清除以前的一切图形并将其设为clear颜色。
    glEnableClientState(GL_VERTEX_ARRAY);// 启动OpenGL的vertex arrays（顶点数组）特性
    glColor4f(1.0, 0.0, 0.0, 1.0);// 设置了绘图时所需的颜色RGBA
    glVertexPointer(3, GL_FLOAT, 0, &triangle);// 设置绘制路径
    glDrawArrays(GL_TRIANGLES, 0, 9);// 绘制三角形
    glDisableClientState(GL_VERTEX_ARRAY);// 禁止先前启动的顶点数组特效

    Triangle3D triangle[2];
    triangle[0].v1 = Vertex3DMake(0.0, 1.0, -3.0);
    triangle[0].v2 = Vertex3DMake(1.0, 0.0, -3.0);
    triangle[0].v3 = Vertex3DMake(-1.0, 0.0, -3.0);
    triangle[1].v1 = Vertex3DMake(-1.0, 0.0, -3.0);
    triangle[1].v2 = Vertex3DMake(1.0, 0.0, -3.0);
    triangle[1].v3 = Vertex3DMake(0.0, -1.0, -3.0);


    glLoadIdentity();
    glClearColor(0.7, 0.7, 0.7, 1.0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glEnableClientState(GL_VERTEX_ARRAY);
    glColor4f(1.0, 0.0, 0.0, 1.0);
    glVertexPointer(3, GL_FLOAT, 0, &triangle);
    glDrawArrays(GL_TRIANGLES, 0, 18);
    glDisableClientState(GL_VERTEX_ARRAY);

static inline void Vertex3DSet(Vertex3D *vertex, CGFloat inX, CGFloat inY, CGFloat inZ)
{
    vertex->x = inX;
    vertex->y = inY;
    vertex->z = inZ;
}

    Triangle3D  *triangles = malloc(sizeof(Triangle3D) * 2);


    Vertex3DSet(&triangles[0].v1, 0.0, 1.0, -3.0);
    Vertex3DSet(&triangles[0].v2, 1.0, 0.0, -3.0);
    Vertex3DSet(&triangles[0].v3, -1.0, 0.0, -3.0);
    Vertex3DSet(&triangles[1].v1, -1.0, 0.0, -3.0);
    Vertex3DSet(&triangles[1].v2, 1.0, 0.0, -3.0);
    Vertex3DSet(&triangles[1].v3, 0.0, -1.0, -3.0);


    glLoadIdentity();
    glClearColor(0.7, 0.7, 0.7, 1.0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glEnableClientState(GL_VERTEX_ARRAY);
    glColor4f(1.0, 0.0, 0.0, 1.0);
    glVertexPointer(3, GL_FLOAT, 0, triangles);
    glDrawArrays(GL_TRIANGLES, 0, 18);
    glDisableClientState(GL_VERTEX_ARRAY);


    if (triangles != NULL)
        free(triangles);

一 数据类型和简单绘制

标签：opengl

原文地址：http://blog.csdn.net/xufeng0991/article/details/45148871