我一直在尝试在Visual Studio Express 2017中运行这个程序。使用opengl。我在一个pdf文件中找到了渲染代码和笔画代码,并尝试了一下,但首先它显示了许多错误,一旦处理好我编译了程序。虽然运行没有任何错误,但输出屏幕仍然是空白的。
# include "stdafx.h"
# include <windows.h>
# include <gl/GL.h>
# include <glut.h>
# include <gl/GLU.h>
void myInit(void)
{
glClearColor(1.0, 1.0, 1.0, 0.0);
glColor3f(0.0f, 0.0f, 0.0f);
glMatrixMode(GL_PROJECTION);
glLineWidth(6.0);
glLoadIdentity();
gluOrtho2D(0.0, 700, 0.0, 700);
}
void drawStrokeText(const char *string, int x, int y, int z)
{
const char *c;
glPushMatrix();
glTranslatef(x, y + 8, z);
glScalef(0.09f, -0.08f, z);
for (c = string; *c != '\0'; c++)
{
glutStrokeCharacter(GLUT_STROKE_ROMAN, *c);
}
glPopMatrix();
}
void render()
{
glClear(GL_COLOR_BUFFER_BIT);
glLoadIdentity();
glColor3ub(255, 50, 255);
drawStrokeText("Hello", 300, 400, 0);
glutSwapBuffers();
}
void myDisplay(void)
{
glClear(GL_COLOR_BUFFER_BIT);
render();
glFlush();
}
int main(int argc, char**argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);
glutInitWindowSize(700, 700);
glutInitWindowPosition(100, 150);
glutCreateWindow("My First Program");
glutDisplayFunc(myDisplay);
myInit();
glutMainLoop();
}
1条答案
按热度按时间2w3rbyxf1#
在
myInit
中,矩阵模式被切换到GL_PROJECTION
,但再也没有切换回来。因此,render
中的glLoadIdentity()
指令将覆盖投影矩阵。您必须在glLoadIdentity()
之前将矩阵模式切换到GL_MODELVIEW
: