【发布时间】:2014-10-28 12:44:17
【问题描述】:
我在使用在 Visual Studio 2012 中编译和运行的 OpenGLUT 的 OpenGL 程序时遇到问题。程序编译良好,当我按下运行时,会打开一个 800 x 600 的窗口并显示我想要的图像。但是,窗口立即开始缩小,直到在大约 2 秒内达到 0 x 0,然后保持打开状态。我不太确定问题出在哪里,谷歌搜索没有找到相关信息。以下是问题的一些截图:
上面的截图是在程序启动后立即截取的。下面的屏幕截图是在程序启动后大约一秒钟拍摄的,我没有进行任何交互。
输出窗口继续缩小,直到大小为 0 x 0。这是我的代码,任何建议都会有所帮助。
#ifdef __APPLE_CC__
#include <GLUT/glut.h>
#else
#include <OpenGlut.h>
#endif
// Clears the window and draws the tetrahedron. The tetrahedron is easily
// specified with a triangle strip, though the specification really isn't very
// easy to read.
void display() {
glClear(GL_COLOR_BUFFER_BIT);
// Draw a white grid "floor" for the tetrahedron to sit on.
glColor3f(1.0, 1.0, 1.0);
glBegin(GL_LINES);
for (GLfloat i = -2.5; i <= 2.5; i += 0.25) {
glVertex3f(i, 0, 2.5); glVertex3f(i, 0, -2.5);
glVertex3f(2.5, 0, i); glVertex3f(-2.5, 0, i);
}
glEnd();
// Draw the tetrahedron. It is a four sided figure, so when defining it
// with a triangle strip we have to repeat the last two vertices.
glBegin(GL_TRIANGLE_STRIP);
glColor3f(1, 1, 1); glVertex3f(0, 2, 0);
glColor3f(1, 0, 0); glVertex3f(-1, 0, 1);
glColor3f(0, 1, 0); glVertex3f(1, 0, 1);
glColor3f(0, 0, 1); glVertex3f(0, 0, -1.4);
glColor3f(1, 1, 1); glVertex3f(0, 2, 0);
glColor3f(1, 0, 0); glVertex3f(-1, 0, 1);
glEnd();
glFlush();
}
// Sets up global attributes like clear color and drawing color, enables and
// initializes any needed modes (in this case we want backfaces culled), and
// sets up the desired projection and modelview matrices. It is cleaner to
// define these operations in a function separate from main().
void init() {
// Set the current clear color to sky blue and the current drawing color to
// white.
glClearColor(0.1, 0.39, 0.88, 1.0);
glColor3f(1.0, 1.0, 1.0);
// Tell the rendering engine not to draw backfaces. Without this code,
// all four faces of the tetrahedron would be drawn and it is possible
// that faces farther away could be drawn after nearer to the viewer.
// Since there is only one closed polyhedron in the whole scene,
// eliminating the drawing of backfaces gives us the realism we need.
// THIS DOES NOT WORK IN GENERAL.
glEnable(GL_CULL_FACE);
glCullFace(GL_BACK);
// Set the camera lens so that we have a perspective viewing volume whose
// horizontal bounds at the near clipping plane are -2..2 and vertical
// bounds are -1.5..1.5. The near clipping plane is 1 unit from the camera
// and the far clipping plane is 40 units away.
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glFrustum(-2, 2, -1.5, 1.5, 1, 40);
// Set up transforms so that the tetrahedron which is defined right at
// the origin will be rotated and moved into the view volume. First we
// rotate 70 degrees around y so we can see a lot of the left side.
// Then we rotate 50 degrees around x to "drop" the top of the pyramid
// down a bit. Then we move the object back 3 units "into the screen".
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0, 0, -3);
glRotatef(50, 1, 0, 0);
glRotatef(70, 0, 1, 0);
}
// Initializes GLUT, the display mode, and main window; registers callbacks;
// does application initialization; enters the main event loop.
int main(int argc, char** argv) {
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
glutInitWindowPosition(80, 80);
glutInitWindowSize(800, 600);
glutCreateWindow("A Simple Tetrahedron");
glutDisplayFunc(display);
init();
glutMainLoop();
}
【问题讨论】:
-
+1 一个真正独特的错误 :-)
-
是否有足够少的代码来发布整个内容,因为目前没有足够的信息。如果它在源代码控制中,请随意链接
-
令人着迷...
display()是您注册的唯一 GLUT 回调吗?没有重塑回调,或类似的东西? -
当您从 OpenGLUT(AFAIK 目前未积极维护)迁移到提供相同 API 的 FreeGLUT 时会发生什么,然后提供更多相同的 API 并得到积极维护。这几乎是您的 GLUT 实现中的一个错误。
-
这非常具有误导性。该问题清楚地表明您一直在使用 FreeGLUT,并且它具有 FreeGLUT 标签。我猜头文件的名称已经泄露了它,但问题应该真正清楚地指定您的配置。