如何使用OpenGL在点的方向上移动2D对象(不是GL_POINTS
,但坐标)?将2D对象移动到OpenGL中的一个点上
为了更好地理解我的代码:
我splited我的大部分代码转换成不同的源代码,但是这是实际创造的形状和设置的场景之一:
void setupScene(int clearColor[]) {
glClearColor(clearColor[0], clearColor[1], clearColor[2], clearColor[3]);
//glClearColor(250, 250, 250, 1.0); // Set the cleared screen colour to black.
glViewport(0, 0, WINDOW_WIDTH, WINDOW_HEIGHT); // This sets up the viewport so that the coordinates (0, 0) are at the top left of the window.
// Set up the orthographic projection so that coordinates (0, 0) are in the top left.
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0, WINDOW_WIDTH, WINDOW_HEIGHT, 0, -10, 10);
// Back to the modelview so we can draw stuff.
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Clear the screen and depth buffer.
}
void drawScene() {
setupScene((int[]){250, 250, 250, 1});
triangle(210, WINDOW_WIDTH, WINDOW_HEIGHT);
glBegin(GL_QUADS);
glColor3f(RGB(80), RGB(80), RGB(80));
glPushMatrix();
glTranslatef(400, 400, 0);
glVertex2d(200, 100);
glVertex2d(100, 100);
glVertex2d(100, 200);
glVertex2d(200, 200);
glPopMatrix();
glEnd();
glutSwapBuffers(); // Send the scene to the screen.
}
void update(int value) {
glutPostRedisplay(); // Tell GLUT that the display has changed.
glutTimerFunc(25, update, 0); // Tell GLUT to call update again in 25 milliseconds.
}
PS:对不起,如果我听起来像一个noob,但我只是从Java到C++,所以我可以做一些跨平台的游戏。此外,我从来没有开发过游戏,只是一些Android,iOS和BlackBerry应用程序。
解决方案
感谢@paddy,我试图了解使用glTranslatef
并与解决方案来。这里是工作的代码,它会在100×100创建一个正方形,并将其移动到400x200:
void setupScene(int clearColor[]) {
glClearColor(clearColor[0], clearColor[1], clearColor[2], clearColor[3]);
//glClearColor(250, 250, 250, 1.0); // Set the cleared screen colour to black.
glViewport(0, 0, WINDOW_WIDTH, WINDOW_HEIGHT); // This sets up the viewport so that the coordinates (0, 0) are at the top left of the window.
// Set up the orthographic projection so that coordinates (0, 0) are in the top left.
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0, WINDOW_WIDTH, WINDOW_HEIGHT, 0, -10, 10);
// Back to the modelview so we can draw stuff.
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Clear the screen and depth buffer.
}
int a = 100;
int b = 200;
int x = 100;
int y = 100;
void drawScene() {
setupScene((int[]){250, 250, 250, 1});
triangle(210, WINDOW_WIDTH, WINDOW_HEIGHT);
glPushMatrix();
glTranslatef(x, y, 0);
glBegin(GL_QUADS);
glColor3f(RGB(80), RGB(80), RGB(80));
glVertex2d(b, a);
glVertex2d(a, a);
glVertex2d(a, b);
glVertex2d(b, b);
glEnd();
glPopMatrix();
glutSwapBuffers(); // Send the scene to the screen.
}
void update(int value) {
if (x != 400 && y != 200) {
x += 4;
y += 2;
}
glutPostRedisplay(); // Tell GLUT that the display has changed.
glutTimerFunc(25, update, 0); // Tell GLUT to call update again in 25 milliseconds.
}
OpenGL是很多比我想象中的简单。因为我总是对C/C++感到恐惧,因为我习惯Java和JavaScript,但我真的很喜欢它的真棒,简单和优雅。谢谢@paddy帮助我。 :)
[你有什么尝试?](http://www.whathaveyoutried.com) – 2012-07-30 23:50:30
@代码大师:有一点帮助,我得到了它的工作。谢谢。 – 2012-07-31 01:06:14
请注意,您并不需要推送和弹出矩阵调用。他们在那里隔离一个操作或者从世界空间建立相关转换。如果你总是在世界空间工作,只需改写矩阵即可。 – paddy 2012-07-31 01:54:06