在OpenGL中渲染二维纹理顶部的红色矩形轮廓
我在这个网站上搜索了很多,但没有找到我的问题所在。大多数类似的问题都使用了控制台和glut库。但是,由于我是OpenGL和MFC的新手,并且是从MFC的组合开始的,所以他们帮不了我很多 我正在为自己的目的定制这个类。但是如果你对下载不感兴趣,没问题,我会解释相关的部分。这可能需要一段时间,所以我希望你能耐心等待 首先,我应该告诉你,我画这样一个矩形的目标是,我想在我的程序中创建这个类的两个实例。在OpenGL中渲染二维纹理顶部的红色矩形轮廓,opengl,mfc,textures,rectangles,texture2d,Opengl,Mfc,Textures,Rectangles,Texture2d,我在这个网站上搜索了很多,但没有找到我的问题所在。大多数类似的问题都使用了控制台和glut库。但是,由于我是OpenGL和MFC的新手,并且是从MFC的组合开始的,所以他们帮不了我很多 我正在为自己的目的定制这个类。但是如果你对下载不感兴趣,没问题,我会解释相关的部分。这可能需要一段时间,所以我希望你能耐心等待 首先,我应该告诉你,我画这样一个矩形的目标是,我想在我的程序中创建这个类的两个实例。 在较小的窗口中,图像将始终处于缩放范围模式,但在较大的窗口中,用户可以执行不同的导航任务。因此,例
在较小的窗口中,图像将始终处于
缩放范围
模式,但在较大的窗口中,用户可以执行不同的导航任务。因此,例如,每次在较大实例的OnDraw
函数中平移或缩放图像时,将计算范围矩形,并将其传递到较小的窗口,并在该窗口中绘制,以显示这样一幅大图像的整体位置
void COpenGLControl::OnSize(UINT nType, int cx, int cy)
{
wglMakeCurrent(hdc, hrc);
CWnd::OnSize(nType, cx, cy);
if (0 >= cx || 0 >= cy || nType == SIZE_MINIMIZED) return;
oglWindowWidth = cx;
oglWindowHeight = cy;
// Map the OpenGL coordinates.
glViewport(0, 0, oglWindowWidth, oglWindowHeight);
// Projection view
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
// Set our current view perspective
glOrtho(-oglWindowWidth/2, oglWindowWidth/2, -oglWindowHeight/2,oglWindowHeight/2, 1, -1);
// Model view
glMatrixMode(GL_MODELVIEW);
wglMakeCurrent(NULL, NULL);
}
void COpenGLControl::OnDraw(CDC *pDC)
{
// TODO: Camera controls
wglMakeCurrent(hdc,hrc);
glLoadIdentity();
gluLookAt(0,0,1,0,0,0,0,1,0);
glTranslatef(m_fPosX, m_fPosY, 0.0f);
glScalef(m_fZoom,m_fZoom,1.0);
setViewRectangle();
if (WantToDrawRectangle)
DrawRectangleOnTopOfTexture();
wglMakeCurrent(NULL, NULL);
}
void COpenGLControl::oglDrawScene(void)
{
wglMakeCurrent(hdc, hrc);
float x0 = -ImageWidth/2; // top left corner of image
float y0 = ImageHeight/2;
float x1 = x0 + ImageWidth; // bottom right corner of image
float y1 = y0 - ImageHeight;
glBegin(GL_TRIANGLE_STRIP);
{
glTexCoord2f(0,1);glVertex2f(x0, y1);
glTexCoord2f(0,0);glVertex2f(x0, y0);
glTexCoord2f(1,1);glVertex2f(x1, y1);
glTexCoord2f(1,0);glVertex2f(x1, y0);
}
glEnd();
wglMakeCurrent(NULL, NULL);
}
void COpenGLControl::setViewRectangle()
{
ViewRectangle.at(0) = m_fPosX - oglWindowWidth*m_fZoomInverse/2;
ViewRectangle.at(1) = m_fPosY - oglWindowHeight*m_fZoomInverse/2;
ViewRectangle.at(2) = m_fPosX + oglWindowWidth*m_fZoomInverse/2;
ViewRectangle.at(3) = m_fPosY + oglWindowHeight*m_fZoomInverse/2;
}
void COpenGLControl::DrawRectangleOnTopOfTexture()
{
wglMakeCurrent(hdc, hrc);
glColor3f(1.0f,0.0f,0.0f);
glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);
glBegin(GL_QUADS);
glVertex3f(RectangleToDraw.at(0),RectangleToDraw.at(1),0.5);
glVertex3f(RectangleToDraw.at(0),RectangleToDraw.at(3),0.5);
glVertex3f(RectangleToDraw.at(2),RectangleToDraw.at(3),0.5);
glVertex3f(RectangleToDraw.at(2),RectangleToDraw.at(1),0.5);
glEnd();
SwapBuffers(hdc);
wglMakeCurrent(NULL, NULL);
}
我遵循了以下步骤:修改投影矩阵堆栈并模拟2D场景
void COpenGLControl::OnSize(UINT nType, int cx, int cy)
{
wglMakeCurrent(hdc, hrc);
CWnd::OnSize(nType, cx, cy);
if (0 >= cx || 0 >= cy || nType == SIZE_MINIMIZED) return;
oglWindowWidth = cx;
oglWindowHeight = cy;
// Map the OpenGL coordinates.
glViewport(0, 0, oglWindowWidth, oglWindowHeight);
// Projection view
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
// Set our current view perspective
glOrtho(-oglWindowWidth/2, oglWindowWidth/2, -oglWindowHeight/2,oglWindowHeight/2, 1, -1);
// Model view
glMatrixMode(GL_MODELVIEW);
wglMakeCurrent(NULL, NULL);
}
void COpenGLControl::OnDraw(CDC *pDC)
{
// TODO: Camera controls
wglMakeCurrent(hdc,hrc);
glLoadIdentity();
gluLookAt(0,0,1,0,0,0,0,1,0);
glTranslatef(m_fPosX, m_fPosY, 0.0f);
glScalef(m_fZoom,m_fZoom,1.0);
setViewRectangle();
if (WantToDrawRectangle)
DrawRectangleOnTopOfTexture();
wglMakeCurrent(NULL, NULL);
}
void COpenGLControl::oglDrawScene(void)
{
wglMakeCurrent(hdc, hrc);
float x0 = -ImageWidth/2; // top left corner of image
float y0 = ImageHeight/2;
float x1 = x0 + ImageWidth; // bottom right corner of image
float y1 = y0 - ImageHeight;
glBegin(GL_TRIANGLE_STRIP);
{
glTexCoord2f(0,1);glVertex2f(x0, y1);
glTexCoord2f(0,0);glVertex2f(x0, y0);
glTexCoord2f(1,1);glVertex2f(x1, y1);
glTexCoord2f(1,0);glVertex2f(x1, y0);
}
glEnd();
wglMakeCurrent(NULL, NULL);
}
void COpenGLControl::setViewRectangle()
{
ViewRectangle.at(0) = m_fPosX - oglWindowWidth*m_fZoomInverse/2;
ViewRectangle.at(1) = m_fPosY - oglWindowHeight*m_fZoomInverse/2;
ViewRectangle.at(2) = m_fPosX + oglWindowWidth*m_fZoomInverse/2;
ViewRectangle.at(3) = m_fPosY + oglWindowHeight*m_fZoomInverse/2;
}
void COpenGLControl::DrawRectangleOnTopOfTexture()
{
wglMakeCurrent(hdc, hrc);
glColor3f(1.0f,0.0f,0.0f);
glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);
glBegin(GL_QUADS);
glVertex3f(RectangleToDraw.at(0),RectangleToDraw.at(1),0.5);
glVertex3f(RectangleToDraw.at(0),RectangleToDraw.at(3),0.5);
glVertex3f(RectangleToDraw.at(2),RectangleToDraw.at(3),0.5);
glVertex3f(RectangleToDraw.at(2),RectangleToDraw.at(1),0.5);
glEnd();
SwapBuffers(hdc);
wglMakeCurrent(NULL, NULL);
}
修改modelview矩阵堆栈并设置摄影机(似乎我们正在查看z轴的负方向)
void COpenGLControl::OnSize(UINT nType, int cx, int cy)
{
wglMakeCurrent(hdc, hrc);
CWnd::OnSize(nType, cx, cy);
if (0 >= cx || 0 >= cy || nType == SIZE_MINIMIZED) return;
oglWindowWidth = cx;
oglWindowHeight = cy;
// Map the OpenGL coordinates.
glViewport(0, 0, oglWindowWidth, oglWindowHeight);
// Projection view
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
// Set our current view perspective
glOrtho(-oglWindowWidth/2, oglWindowWidth/2, -oglWindowHeight/2,oglWindowHeight/2, 1, -1);
// Model view
glMatrixMode(GL_MODELVIEW);
wglMakeCurrent(NULL, NULL);
}
void COpenGLControl::OnDraw(CDC *pDC)
{
// TODO: Camera controls
wglMakeCurrent(hdc,hrc);
glLoadIdentity();
gluLookAt(0,0,1,0,0,0,0,1,0);
glTranslatef(m_fPosX, m_fPosY, 0.0f);
glScalef(m_fZoom,m_fZoom,1.0);
setViewRectangle();
if (WantToDrawRectangle)
DrawRectangleOnTopOfTexture();
wglMakeCurrent(NULL, NULL);
}
void COpenGLControl::oglDrawScene(void)
{
wglMakeCurrent(hdc, hrc);
float x0 = -ImageWidth/2; // top left corner of image
float y0 = ImageHeight/2;
float x1 = x0 + ImageWidth; // bottom right corner of image
float y1 = y0 - ImageHeight;
glBegin(GL_TRIANGLE_STRIP);
{
glTexCoord2f(0,1);glVertex2f(x0, y1);
glTexCoord2f(0,0);glVertex2f(x0, y0);
glTexCoord2f(1,1);glVertex2f(x1, y1);
glTexCoord2f(1,0);glVertex2f(x1, y0);
}
glEnd();
wglMakeCurrent(NULL, NULL);
}
void COpenGLControl::setViewRectangle()
{
ViewRectangle.at(0) = m_fPosX - oglWindowWidth*m_fZoomInverse/2;
ViewRectangle.at(1) = m_fPosY - oglWindowHeight*m_fZoomInverse/2;
ViewRectangle.at(2) = m_fPosX + oglWindowWidth*m_fZoomInverse/2;
ViewRectangle.at(3) = m_fPosY + oglWindowHeight*m_fZoomInverse/2;
}
void COpenGLControl::DrawRectangleOnTopOfTexture()
{
wglMakeCurrent(hdc, hrc);
glColor3f(1.0f,0.0f,0.0f);
glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);
glBegin(GL_QUADS);
glVertex3f(RectangleToDraw.at(0),RectangleToDraw.at(1),0.5);
glVertex3f(RectangleToDraw.at(0),RectangleToDraw.at(3),0.5);
glVertex3f(RectangleToDraw.at(2),RectangleToDraw.at(3),0.5);
glVertex3f(RectangleToDraw.at(2),RectangleToDraw.at(1),0.5);
glEnd();
SwapBuffers(hdc);
wglMakeCurrent(NULL, NULL);
}
行setViewRectangle()
用于计算类的一个公共成员数据vectorViewRectangle
,如果用户需要,将使用vectorRectangleToDraw
其他公共成员数据来绘制矩形。这是因为我们不希望在大窗口中绘制这样一个矩形,但在较小的窗口中我们可以。较小的将使用较大的数据。但是我还没有实现如何在一个类的两个实例之间实时传递这些数据因此,在尝试该类时,我将
RectangleToDraw
的初始值设置为如下所示,并且由于窗口是由glOrtho
设置的[0,0573543]
,因此我认为应该在纹理顶部的中心绘制矩形。但事实并非如此。无论如何
编码以应用将在OnTimer中调用的纹理
void COpenGLControl::OnSize(UINT nType, int cx, int cy)
{
wglMakeCurrent(hdc, hrc);
CWnd::OnSize(nType, cx, cy);
if (0 >= cx || 0 >= cy || nType == SIZE_MINIMIZED) return;
oglWindowWidth = cx;
oglWindowHeight = cy;
// Map the OpenGL coordinates.
glViewport(0, 0, oglWindowWidth, oglWindowHeight);
// Projection view
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
// Set our current view perspective
glOrtho(-oglWindowWidth/2, oglWindowWidth/2, -oglWindowHeight/2,oglWindowHeight/2, 1, -1);
// Model view
glMatrixMode(GL_MODELVIEW);
wglMakeCurrent(NULL, NULL);
}
void COpenGLControl::OnDraw(CDC *pDC)
{
// TODO: Camera controls
wglMakeCurrent(hdc,hrc);
glLoadIdentity();
gluLookAt(0,0,1,0,0,0,0,1,0);
glTranslatef(m_fPosX, m_fPosY, 0.0f);
glScalef(m_fZoom,m_fZoom,1.0);
setViewRectangle();
if (WantToDrawRectangle)
DrawRectangleOnTopOfTexture();
wglMakeCurrent(NULL, NULL);
}
void COpenGLControl::oglDrawScene(void)
{
wglMakeCurrent(hdc, hrc);
float x0 = -ImageWidth/2; // top left corner of image
float y0 = ImageHeight/2;
float x1 = x0 + ImageWidth; // bottom right corner of image
float y1 = y0 - ImageHeight;
glBegin(GL_TRIANGLE_STRIP);
{
glTexCoord2f(0,1);glVertex2f(x0, y1);
glTexCoord2f(0,0);glVertex2f(x0, y0);
glTexCoord2f(1,1);glVertex2f(x1, y1);
glTexCoord2f(1,0);glVertex2f(x1, y0);
}
glEnd();
wglMakeCurrent(NULL, NULL);
}
void COpenGLControl::setViewRectangle()
{
ViewRectangle.at(0) = m_fPosX - oglWindowWidth*m_fZoomInverse/2;
ViewRectangle.at(1) = m_fPosY - oglWindowHeight*m_fZoomInverse/2;
ViewRectangle.at(2) = m_fPosX + oglWindowWidth*m_fZoomInverse/2;
ViewRectangle.at(3) = m_fPosY + oglWindowHeight*m_fZoomInverse/2;
}
void COpenGLControl::DrawRectangleOnTopOfTexture()
{
wglMakeCurrent(hdc, hrc);
glColor3f(1.0f,0.0f,0.0f);
glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);
glBegin(GL_QUADS);
glVertex3f(RectangleToDraw.at(0),RectangleToDraw.at(1),0.5);
glVertex3f(RectangleToDraw.at(0),RectangleToDraw.at(3),0.5);
glVertex3f(RectangleToDraw.at(2),RectangleToDraw.at(3),0.5);
glVertex3f(RectangleToDraw.at(2),RectangleToDraw.at(1),0.5);
glEnd();
SwapBuffers(hdc);
wglMakeCurrent(NULL, NULL);
}
计算将传递给类的另一个实例的ViewRectangle
的代码
void COpenGLControl::OnSize(UINT nType, int cx, int cy)
{
wglMakeCurrent(hdc, hrc);
CWnd::OnSize(nType, cx, cy);
if (0 >= cx || 0 >= cy || nType == SIZE_MINIMIZED) return;
oglWindowWidth = cx;
oglWindowHeight = cy;
// Map the OpenGL coordinates.
glViewport(0, 0, oglWindowWidth, oglWindowHeight);
// Projection view
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
// Set our current view perspective
glOrtho(-oglWindowWidth/2, oglWindowWidth/2, -oglWindowHeight/2,oglWindowHeight/2, 1, -1);
// Model view
glMatrixMode(GL_MODELVIEW);
wglMakeCurrent(NULL, NULL);
}
void COpenGLControl::OnDraw(CDC *pDC)
{
// TODO: Camera controls
wglMakeCurrent(hdc,hrc);
glLoadIdentity();
gluLookAt(0,0,1,0,0,0,0,1,0);
glTranslatef(m_fPosX, m_fPosY, 0.0f);
glScalef(m_fZoom,m_fZoom,1.0);
setViewRectangle();
if (WantToDrawRectangle)
DrawRectangleOnTopOfTexture();
wglMakeCurrent(NULL, NULL);
}
void COpenGLControl::oglDrawScene(void)
{
wglMakeCurrent(hdc, hrc);
float x0 = -ImageWidth/2; // top left corner of image
float y0 = ImageHeight/2;
float x1 = x0 + ImageWidth; // bottom right corner of image
float y1 = y0 - ImageHeight;
glBegin(GL_TRIANGLE_STRIP);
{
glTexCoord2f(0,1);glVertex2f(x0, y1);
glTexCoord2f(0,0);glVertex2f(x0, y0);
glTexCoord2f(1,1);glVertex2f(x1, y1);
glTexCoord2f(1,0);glVertex2f(x1, y0);
}
glEnd();
wglMakeCurrent(NULL, NULL);
}
void COpenGLControl::setViewRectangle()
{
ViewRectangle.at(0) = m_fPosX - oglWindowWidth*m_fZoomInverse/2;
ViewRectangle.at(1) = m_fPosY - oglWindowHeight*m_fZoomInverse/2;
ViewRectangle.at(2) = m_fPosX + oglWindowWidth*m_fZoomInverse/2;
ViewRectangle.at(3) = m_fPosY + oglWindowHeight*m_fZoomInverse/2;
}
void COpenGLControl::DrawRectangleOnTopOfTexture()
{
wglMakeCurrent(hdc, hrc);
glColor3f(1.0f,0.0f,0.0f);
glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);
glBegin(GL_QUADS);
glVertex3f(RectangleToDraw.at(0),RectangleToDraw.at(1),0.5);
glVertex3f(RectangleToDraw.at(0),RectangleToDraw.at(3),0.5);
glVertex3f(RectangleToDraw.at(2),RectangleToDraw.at(3),0.5);
glVertex3f(RectangleToDraw.at(2),RectangleToDraw.at(1),0.5);
glEnd();
SwapBuffers(hdc);
wglMakeCurrent(NULL, NULL);
}
在纹理顶部绘制矩形的代码
void COpenGLControl::OnSize(UINT nType, int cx, int cy)
{
wglMakeCurrent(hdc, hrc);
CWnd::OnSize(nType, cx, cy);
if (0 >= cx || 0 >= cy || nType == SIZE_MINIMIZED) return;
oglWindowWidth = cx;
oglWindowHeight = cy;
// Map the OpenGL coordinates.
glViewport(0, 0, oglWindowWidth, oglWindowHeight);
// Projection view
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
// Set our current view perspective
glOrtho(-oglWindowWidth/2, oglWindowWidth/2, -oglWindowHeight/2,oglWindowHeight/2, 1, -1);
// Model view
glMatrixMode(GL_MODELVIEW);
wglMakeCurrent(NULL, NULL);
}
void COpenGLControl::OnDraw(CDC *pDC)
{
// TODO: Camera controls
wglMakeCurrent(hdc,hrc);
glLoadIdentity();
gluLookAt(0,0,1,0,0,0,0,1,0);
glTranslatef(m_fPosX, m_fPosY, 0.0f);
glScalef(m_fZoom,m_fZoom,1.0);
setViewRectangle();
if (WantToDrawRectangle)
DrawRectangleOnTopOfTexture();
wglMakeCurrent(NULL, NULL);
}
void COpenGLControl::oglDrawScene(void)
{
wglMakeCurrent(hdc, hrc);
float x0 = -ImageWidth/2; // top left corner of image
float y0 = ImageHeight/2;
float x1 = x0 + ImageWidth; // bottom right corner of image
float y1 = y0 - ImageHeight;
glBegin(GL_TRIANGLE_STRIP);
{
glTexCoord2f(0,1);glVertex2f(x0, y1);
glTexCoord2f(0,0);glVertex2f(x0, y0);
glTexCoord2f(1,1);glVertex2f(x1, y1);
glTexCoord2f(1,0);glVertex2f(x1, y0);
}
glEnd();
wglMakeCurrent(NULL, NULL);
}
void COpenGLControl::setViewRectangle()
{
ViewRectangle.at(0) = m_fPosX - oglWindowWidth*m_fZoomInverse/2;
ViewRectangle.at(1) = m_fPosY - oglWindowHeight*m_fZoomInverse/2;
ViewRectangle.at(2) = m_fPosX + oglWindowWidth*m_fZoomInverse/2;
ViewRectangle.at(3) = m_fPosY + oglWindowHeight*m_fZoomInverse/2;
}
void COpenGLControl::DrawRectangleOnTopOfTexture()
{
wglMakeCurrent(hdc, hrc);
glColor3f(1.0f,0.0f,0.0f);
glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);
glBegin(GL_QUADS);
glVertex3f(RectangleToDraw.at(0),RectangleToDraw.at(1),0.5);
glVertex3f(RectangleToDraw.at(0),RectangleToDraw.at(3),0.5);
glVertex3f(RectangleToDraw.at(2),RectangleToDraw.at(3),0.5);
glVertex3f(RectangleToDraw.at(2),RectangleToDraw.at(1),0.5);
glEnd();
SwapBuffers(hdc);
wglMakeCurrent(NULL, NULL);
}
即使在上述函数中使用glVertex2f
也没有任何区别,在这两种情况下,我都会遇到:别弄糊涂了。在两个窗口上应用错误图形的原因是我在构造函数中设置了:
WantToDrawRectangle = true;
RectangleToDraw.at(0) = -100;
RectangleToDraw.at(1) = -100;
RectangleToDraw.at(2) = 100;
RectangleToDraw.at(3) = 100;
仅用于尝试如何在纹理顶部绘制矩形。当然,在编写正确的代码之后,我会将它们设置为true模式。告诉我
如何最好以面向对象的方式在纹理顶部绘制矩形,以便我需要实时渲染?由于在现代OpenGL中不推荐使用
边缘标志
,因此我将避免使用多边形填充模式来绘制轮廓。如果我没有弄错你的截图,你会在画矩形的两个三角形的内边缘画线
void COpenGLControl::OnSize(UINT nType, int cx, int cy)
{
wglMakeCurrent(hdc, hrc);
CWnd::OnSize(nType, cx, cy);
if (0 >= cx || 0 >= cy || nType == SIZE_MINIMIZED) return;
oglWindowWidth = cx;
oglWindowHeight = cy;
// Map the OpenGL coordinates.
glViewport(0, 0, oglWindowWidth, oglWindowHeight);
// Projection view
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
// Set our current view perspective
glOrtho(-oglWindowWidth/2, oglWindowWidth/2, -oglWindowHeight/2,oglWindowHeight/2, 1, -1);
// Model view
glMatrixMode(GL_MODELVIEW);
wglMakeCurrent(NULL, NULL);
}
void COpenGLControl::OnDraw(CDC *pDC)
{
// TODO: Camera controls
wglMakeCurrent(hdc,hrc);
glLoadIdentity();
gluLookAt(0,0,1,0,0,0,0,1,0);
glTranslatef(m_fPosX, m_fPosY, 0.0f);
glScalef(m_fZoom,m_fZoom,1.0);
setViewRectangle();
if (WantToDrawRectangle)
DrawRectangleOnTopOfTexture();
wglMakeCurrent(NULL, NULL);
}
void COpenGLControl::oglDrawScene(void)
{
wglMakeCurrent(hdc, hrc);
float x0 = -ImageWidth/2; // top left corner of image
float y0 = ImageHeight/2;
float x1 = x0 + ImageWidth; // bottom right corner of image
float y1 = y0 - ImageHeight;
glBegin(GL_TRIANGLE_STRIP);
{
glTexCoord2f(0,1);glVertex2f(x0, y1);
glTexCoord2f(0,0);glVertex2f(x0, y0);
glTexCoord2f(1,1);glVertex2f(x1, y1);
glTexCoord2f(1,0);glVertex2f(x1, y0);
}
glEnd();
wglMakeCurrent(NULL, NULL);
}
void COpenGLControl::setViewRectangle()
{
ViewRectangle.at(0) = m_fPosX - oglWindowWidth*m_fZoomInverse/2;
ViewRectangle.at(1) = m_fPosY - oglWindowHeight*m_fZoomInverse/2;
ViewRectangle.at(2) = m_fPosX + oglWindowWidth*m_fZoomInverse/2;
ViewRectangle.at(3) = m_fPosY + oglWindowHeight*m_fZoomInverse/2;
}
void COpenGLControl::DrawRectangleOnTopOfTexture()
{
wglMakeCurrent(hdc, hrc);
glColor3f(1.0f,0.0f,0.0f);
glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);
glBegin(GL_QUADS);
glVertex3f(RectangleToDraw.at(0),RectangleToDraw.at(1),0.5);
glVertex3f(RectangleToDraw.at(0),RectangleToDraw.at(3),0.5);
glVertex3f(RectangleToDraw.at(2),RectangleToDraw.at(3),0.5);
glVertex3f(RectangleToDraw.at(2),RectangleToDraw.at(1),0.5);
glEnd();
SwapBuffers(hdc);
wglMakeCurrent(NULL, NULL);
}
取而代之的是,画一个红色的GL\u LINE\u LOOP
,它使用矩形的4个角。。。出于可移植性的原因,这是首选的技术,因为GL_四边形
也不推荐使用
glColor3f (1.0f, 0.0f, 0.0f);
glBegin (GL_LINE_LOOP);
glVertex3f (RectangleToDraw.at (0), RectangleToDraw.at (1), -1.0f);
glVertex3f (RectangleToDraw.at (0), RectangleToDraw.at (3), -1.0f);
glVertex3f (RectangleToDraw.at (2), RectangleToDraw.at (3), -1.0f);
glVertex3f (RectangleToDraw.at (2), RectangleToDraw.at (1), -1.0f);
glEnd ();
此外,您的屏幕截图似乎正在遭受尝试纹理轮廓的痛苦。在绘制线条之前禁用
GL\u TEXTURE\u 2D
。由于在现代OpenGL中不推荐使用边缘标志
,因此我将避免使用多边形填充模式绘制轮廓。如果我没有弄错你的截图,你会在画矩形的两个三角形的内边缘画线
取而代之的是,画一个红色的GL\u LINE\u LOOP
,它使用矩形的4个角。。。出于可移植性的原因,这是首选的技术,因为GL_四边形
也不推荐使用
glColor3f (1.0f, 0.0f, 0.0f);
glBegin (GL_LINE_LOOP);
glVertex3f (RectangleToDraw.at (0), RectangleToDraw.at (1), -1.0f);
glVertex3f (RectangleToDraw.at (0), RectangleToDraw.at (3), -1.0f);
glVertex3f (RectangleToDraw.at (2), RectangleToDraw.at (3), -1.0f);
glVertex3f (RectangleToDraw.at (2), RectangleToDraw.at (1), -1.0f);
glEnd ();
此外,您的屏幕截图似乎正在遭受尝试纹理轮廓的痛苦。在绘制线条之前,请禁用
GL\U TEXTURE\U 2D
。您使用的OpenGL版本是什么?您使用的OpenGL版本是什么?听取了您的建议,但只绘制了一个比每次缩放时的图像大的填充红色矩形。@sepideh:这没有任何意义,您是否使用了GL\u LINE\u LOOP
?是的,我应该学习glut库,首先使用glut绘制图形,然后在此程序中学习我的经验@塞皮德:哦,我想是你忘了将glColor3f(…)
设置回正常状态(可能是1.0f、1.0f、1.0f),然后重新启用GL\u纹理2D
。请记住,OpenGL是一个相当简单的状态机,它具有使用“当前”状态并绑定然后修改的恼人特性。在传统的OpenGL中总是有属性堆栈
(例如glPushAttrib(…)
和glpopatrib(…)
)。@sepideh:嗯,你现在正在学习不推荐的OpenGL,像glBegin(…)、glEnable(glu TEXTURE_2D)等东西在现代OpenGL中都是无效的。如果你想学习现代的OpenGL,它似乎非常流行。它有一个更高的学习曲线,因为没有着色器您无法做任何事情,并且您一直使用的这个MFC OpenGL控制类最终必须重新编写以获得OpenGL核心上下文。但是,如果可以避免的话,最好不要学习旧的API。接受了您的建议,但只绘制了一个比每次缩放时的图像大的填充红色矩形。@sepideh:这没有任何意义,您是否使用了GL\u LINE\u LOOP
?是的,似乎我应该学习glut库,首先使用glut绘制图形,然后利用我的经验