我渲染 2D(基于图块)场景并注册按键。按下箭头键时,我移动相机。虽然按键注册得很好,但我的场景在我切换到另一个窗口并返回之前不会更新。
你能给我一个关于是什么导致问题的线索吗?
PS。我在Linux上工作,在glut ( freeglut )的帮助下开发OpenGL应用程序。
我的渲染功能:
void render() {
glClear(GL_COLOR_BUFFER_BIT);
glLoadIdentity();
if (s_map)
for (int i = s_iCameraX; i < sc_iTilesY + s_iCameraY && i < s_map->usiHeight; i++)
{
for (int j = s_iCameraY; j < sc_iTilesX + s_iCameraX && j < s_map->usiWidth; j++)
{
short val = s_map->data[i][j];
if (val == 0x0010) glBindTexture(GL_TEXTURE_2D, texture[0]);
else if (val == 0x0020) glBindTexture(GL_TEXTURE_2D, texture[1]);
glBegin(GL_QUADS);
glTexCoord2f(0.0f, 0.0f); glVertex2f(j-s_iCameraX, i-s_iCameraY);
glTexCoord2f(1.0f, 0.0f); glVertex2f(j-s_iCameraX+1.0f, i-s_iCameraY);
glTexCoord2f(1.0f, 1.0f); glVertex2f(j-s_iCameraX+1.0f, i-s_iCameraY+1.0f);
glTexCoord2f(0.0f, 1.0f); glVertex2f(j-s_iCameraX, i-s_iCameraY+1.0f);
glEnd();
}
}
glutSwapBuffers();
}
我的特殊按键处理功能:
void keyproc(int key, int x, int y) {
switch (key)
{
case GLUT_KEY_UP:
printf("UP: %d %d\n", s_iCameraX, s_iCameraY);
if (s_iCameraY - 1 >= 0) s_iCameraY--;
break;
case GLUT_KEY_DOWN:
printf("DOWN: %d %d\n", s_iCameraX, s_iCameraY);
if (s_map && s_iCameraY + 1 < s_map->usiHeight) s_iCameraY++;
break;
case GLUT_KEY_RIGHT:
printf("RIGHT: %d %d\n", s_iCameraX, s_iCameraY);
if (s_map && s_iCameraX + 1 < s_map->usiWidth) s_iCameraX++;
break;
case GLUT_KEY_LEFT:
printf("LEFT: %d %d\n", s_iCameraX, s_iCameraY);
if (s_iCameraX - 1 >= 0) s_iCameraX--;
break;
default: break;
}
}