Хочу нарисовать аквариум (контейнер) стоящий на столе.
Стены аквариума необходимо смешать.
Но если я сначала нарисую стол, а затем аквариум, то получу:
- глядя из-за стола: хорошо
- глядя с нижней части стола: неправильно, я все еще вижу аквариум
Если я сначала нарисую водолея, а затем таблицу, то получу:
- взгляд из-за стола: неправильно, стены аквариума не влияют на стол (хотя они влияют на фон)
- глядя с нижней части стола: неправильно, я все еще вижу аквариум
Есть картинка, которая это объясняет:
http://img213.imageshack.us/img213/6609/pictureem.jpg
Код:
main.cpp
int DrawGLScene(GLvoid)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);
Cam.SetPrespective();
//----------------
GLfloat LightPosition0[]= { 0.0, 0.0, 0.2, 1.0f };
GLfloat LightAmbient0[]= { 0, 0, 0, 1.0f };
GLfloat LightDiffuse0[]= { 1.0f, 1.0f, 1.0f, 1.0f };
GLfloat LightSpecular0[]= { 1.0f, 1.0f, 1.0f, 1.0f };
glLightfv(GL_LIGHT0, GL_AMBIENT, LightAmbient0); // Setup The Ambient Light
glLightfv(GL_LIGHT0, GL_POSITION,LightPosition0); // Position The Light
glLightfv(GL_LIGHT0, GL_DIFFUSE, LightDiffuse0); // Setup The Diffuse Light
glLightfv(GL_LIGHT0, GL_SPECULAR, LightSpecular0); // Setup The Diffuse Light
glEnable(GL_LIGHT0);
glEnable(GL_COLOR_MATERIAL);
glColorMaterial(GL_FRONT, GL_AMBIENT_AND_DIFFUSE);
//----------------
glLightfv(GL_LIGHT1, GL_AMBIENT, LightAmbient); // Setup The Ambient Light
glLightfv(GL_LIGHT2, GL_POSITION,LightPosition); // Position The Light
glLightfv(GL_LIGHT2, GL_DIFFUSE, LightDiffuse); // Setup The Diffuse Light
drawContainer(); //container drawn first in this example
//.. draw other things
drawTable();
drawGround();
/*
//.. draw other things
drawTable();
drawGround();
drawContainer(); //container drawn last in this example
*/
CheckKeys();
if(mouse)
{
CheckMouse();
}
return TRUE;
}
void drawTable()
{
glColor3f(1.0f, 0.5f, 1.0f);
GLfloat cx = MIN_X+(MAX_X-MIN_X)/2.0f;
GLfloat cy = MIN_Y-0.1f;
GLfloat cz = MIN_Z+(MAX_Z-MIN_Z)/2.0f;
GLfloat cr = sqrt((MAX_X-MIN_X)*(MAX_X-MIN_X)+(MAX_Z-MIN_Z)*(MAX_Z-MIN_Z))*0.85f;
int th = 5.0f; //centerPieceThickness
drawCylinder(cx,cy,cz,th,cr);
glColor3f(0.7f, 0.5f, 0.5f);
drawCylinder(MAX_X+cr*0.155f, cy-th, MAX_Z+cr*0.155f, 25*th, cr*0.035f);
drawCylinder(MAX_X+cr*0.155f, cy-th, MIN_Z-cr*0.155f, 25*th, cr*0.035f);
drawCylinder(MIN_X-cr*0.155f, cy-th, MIN_Z-cr*0.155f, 25*th, cr*0.035f);
drawCylinder(MIN_X-cr*0.155f, cy-th, MAX_Z+cr*0.155f, 25*th, cr*0.035f);
}
void drawGround()
{
int th = 5.0f;
GLfloat cx = MIN_X+(MAX_X-MIN_X)/2.0f;
GLfloat cy = MIN_Y-0.1f;
GLfloat cz = MIN_Z+(MAX_Z-MIN_Z)/2.0f;
GLfloat cr = sqrt((MAX_X-MIN_X)*(MAX_X-MIN_X)+(MAX_Z-MIN_Z)*(MAX_Z-MIN_Z))*8.5f;
glColor3f(0.0f, 0.6f, 0.0f);
drawCylinder(cx,cy-26*th,cz,10.f,cr);
}
void drawContainer()
{
glColor3f(0.2f, 0.2f, 0.2f);
drawCuboid(MIN_X-0.5, MAX_X+0.5f, MIN_Y-0.5, MIN_Y+0.5, MIN_Z-0.5f, MIN_Z+0.5f);
drawCuboid(MIN_X-0.5, MAX_X+0.5f, MIN_Y-0.5, MIN_Y+0.5, MAX_Z-0.5f, MAX_Z+0.5f);
drawCuboid(MIN_X-0.5, MAX_X+0.5f, MAX_Y-0.5, MAX_Y+0.5, MIN_Z-0.5f, MIN_Z+0.5f);
drawCuboid(MIN_X-0.5, MAX_X+0.5f, MAX_Y-0.5, MAX_Y+0.5, MAX_Z-0.5f, MAX_Z+0.5f);
drawCuboid(MIN_X-0.5, MIN_X+0.5f, MIN_Y-0.5, MAX_Y+0.5, MIN_Z-0.5f, MIN_Z+0.5f);
drawCuboid(MIN_X-0.5, MIN_X+0.5f, MIN_Y-0.5, MAX_Y+0.5, MAX_Z-0.5f, MAX_Z+0.5f);
drawCuboid(MAX_X-0.5, MAX_X+0.5f, MIN_Y-0.5, MAX_Y+0.5, MIN_Z-0.5f, MIN_Z+0.5f);
drawCuboid(MAX_X-0.5, MAX_X+0.5f, MIN_Y-0.5, MAX_Y+0.5, MAX_Z-0.5f, MAX_Z+0.5f);
drawCuboid(MIN_X-0.5, MIN_X+0.5f, MIN_Y-0.5, MIN_Y+0.5, MIN_Z-0.5f, MAX_Z+0.5f);
drawCuboid(MIN_X-0.5, MIN_X+0.5f, MAX_Y-0.5, MAX_Y+0.5, MIN_Z-0.5f, MAX_Z+0.5f);
drawCuboid(MAX_X-0.5, MAX_X+0.5f, MIN_Y-0.5, MIN_Y+0.5, MIN_Z-0.5f, MAX_Z+0.5f);
drawCuboid(MAX_X-0.5, MAX_X+0.5f, MAX_Y-0.5, MAX_Y+0.5, MIN_Z-0.5f, MAX_Z+0.5f);
glEnable(GL_BLEND);
glDisable(GL_DEPTH_TEST);
glColor4f(0.5f,1.0f,1.0f,0.12f);
drawCuboid(MIN_X,MAX_X,MIN_Y,MAX_Y,MIN_Z,MAX_Z);
glDisable(GL_BLEND);
glEnable(GL_DEPTH_TEST);
}