我认为我绘制的 2D 平面与屏幕不平行。
首先,在我的调整窗口大小函数中,我放了:
static void Resize(int w, int h)
{
width = w;
height = h;
glViewport(0, 0, width, height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
float32 ratio = width / height;
b2Vec2 extents(ratio * 25.0f, 25.0f);
extents *= viewZoom;
b2Vec2 lower = settings.viewCenter - extents;
b2Vec2 upper = settings.viewCenter + extents;
gluOrtho2D(lower.x, upper.x, lower.y, upper.y);
}
这是我初始化opengl的方法。
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA );
glutInitWindowSize(width, height);
mainWindow = glutCreateWindow("window");
和绘图功能:
void drawScene() {
glClear(GL_COLOR_BUFFER_BIT );
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, texture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glColor3f(1.0f, 1.0f, 1.0f);
glBegin(GL_QUADS);
glTexCoord2f(0.0f, 0.0f);
glVertex2f(cords[0].x,cords[0].y);
glTexCoord2f(1.0f, 0.0f);
glVertex2f(cords[1].x,cords[1].y);
glTexCoord2f(1.0f, 1.0f);
glVertex2f(cords[2].x,cords[2].y);
glTexCoord2f(0.0f, 1.0f);
glVertex2f(cords[3].x,cords[3].y);
glEnd();
glDisable(GL_BLEND);
glDisable(GL_TEXTURE_2D);
glutSwapBuffers();
}
我认为代码没有问题,因为我已经为 ModelView 和 Projection 加载了标识。我画的结果是,如果我的矩形与水平线平行,那么它就是一个矩形,当转动某个角度时,它就变成了倾斜的。似乎我正在绘制的飞机向后倾斜。