Problem with GLUT
When i try to run this code after compiling it, i got only a window border without content, so where is the error?
Note: i am using ubuntu and gcc for compiling
gcc -lglut Simple.c -o Simple
The output
#include <GL/glut.h> // Header File For The GLUT Library
#include <GL/gl.h> // Header File For The OpenGL Library
#include <GL/glu.h> // Header File For The GLu Library
void SetupRC(void);
void RenderScene(void);
void ChangeSize(GLsizei w, GLsizei h);
// Called to draw scene
void RenderScene(void)
{
// Clear the window with current clearing color
glClear(GL_COLOR_BUFFER_BIT);
// set the color to these values
// R G B
glColor3f(56.0f, 19.0f,68.0f);
// Draw a filled rectangle with current color
glRectf(-25.0f, 50.0f, 50.0f, -25.0f);
// Flush drawing commands
glFlush();
}
int main(int argc, char* argv[])
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DEPTH | GLUT_SINGLE | GLUT_RGBA);
glutInitWindowPosition(400,200);
glutInitWindowSize(640,468);
glutCreateWindow("Simple");
glutDisplayFunc(RenderScene);
glutReshapeFunc(ChangeSize);
SetupRC();
glutMainLoop();
return 0;
}
// Setup the rendering state
void SetupRC(void)
{
glClearColor(0.0f, 2.0f, 1.0f, 0.0f);
}
// Handling window resizing
void ChangeSize(GLsizei w, GLsizei h)
{
GLfloat aspectRatio;
// Prevent divide by zero
if (h == 0)
h = 1;
// Set Viewport to window dimensions
glViewport(0, 0, w, h);
// Reset coordinate system
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
// Establish clipping volume (left, right, bottom,开发者_开发百科 top, near, far)
aspectRatio = (GLfloat) w / (GLfloat) h;
if (w <= h) {
glOrtho(-100.0, 100.0, -100 / aspectRatio, 100.0 / aspectRatio, 1.0, -1.0);
}
else
glOrtho(-100.0 * aspectRatio, 100.0 * aspectRatio, -100.0, 100.0, 1.0, -1.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
Try adding a glutSwapBuffers()
to the end of RenderScene()
.
One thing. You have a depth buffer so you should also add GL_DEPTH_BUFFER_BIT to the clear call.
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
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