我真的不知道该怎么办了。我已经让我的应用程序使用 VBO,而我的 cpu 使用率仍然进入 70 年代和 80 年代。我的渲染过程是这样的:
如果形状没有被细分,则设置相机变换,对其进行细分。如果它有 VBO,则创建它的 VBO,使用它。
你会注意到我也有显示列表,如果不支持 VBO,我可能会使用这些。我去找了一个 OpenGL 演示,它可以在我的 PC 上以 60fps 的速度渲染一个 32000 多边形网格,并使用 4% 的 cpu。我正在使用 vbos 以 60fps 的速度渲染大约 10,000 个多边形,并且使用 70-80%。
这是我的渲染过程:
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
POINT hh = controls.MainGlFrame.GetMousePos();
POINTFLOAT S;
S.x = static_cast<float>(hh.x);
S.y = static_cast<float>(hh.y);
POINTFLOAT t;
t.x = 256;
t.y = 256;
POINT dimensions;
dimensions.x = 512;
dimensions.y = 512;
glDeleteTextures(1,&texName);
texName = functions.CreateGradient(col,t,S,512,512,true);
itt = true;
}
HDC hdc;
PAINTSTRUCT ps;
glEnable(GL_MULTISAMPLE_ARB);
glEnable(GL_BLEND);
glBlendFunc (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
hdc = BeginPaint(controls.MainGlContext.mhWnd,&ps);
//start OGL code
glClearColor( 1.0f, 1.0f, 1.0f, 0.0f );
if(!current.isdrawing)
glClear( GL_COLOR_BUFFER_BIT );
glPushMatrix();
glTranslatef(controls.MainGlFrame.GetCameraX(),
controls.MainGlFrame.GetCameraY(),0);
//glTranslatef(current.ScalePoint.x,current.ScalePoint.y,0);
glScalef(current.ScaleFactor,current.ScaleFactor,current.ScaleFactor);
//glTranslatef(-current.ScalePoint.x,-current.ScalePoint.y,0);
if(!current.isdrawing)
{
for(unsigned int currentlayer = 0; currentlayer < layer.size(); ++currentlayer)
{
PolygonTesselator.Init();
for(unsigned int i = 0; i < layer[currentlayer].Shapes.size(); i++)
{
if(layer[currentlayer].Shapes[i].DisplayListInt == -999)
{
gluTessNormal(PolygonTesselator.tobj, 0, 0, 1);
PolygonTesselator.Set_Winding_Rule(layer[currentlayer].Shapes[i].WindingRule);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, texName);
layer[currentlayer].Shapes[i].DisplayListInt = glGenLists(1);
glNewList(layer[currentlayer].Shapes[i].DisplayListInt,GL_COMPILE);
PolygonTesselator.SetDimensions(layer[currentlayer].Shapes[i].Dimensions,layer[currentlayer].Shapes[i].minima);
PolygonTesselator.Begin_Polygon();
for(unsigned int c = 0; c < layer[currentlayer].Shapes[i].Contour.size(); ++c)
{
if(layer[currentlayer].Shapes[i].Color.a != 0)
{
PolygonTesselator.Begin_Contour();
for(unsigned int j = 0; j < layer[currentlayer].Shapes[i].Contour[c].DrawingPoints.size(); ++j)
{
gluTessVertex(PolygonTesselator.tobj,&layer[currentlayer].Shapes[i].Contour[c].DrawingPoints[j][0],
&layer[currentlayer].Shapes[i].Contour[c].DrawingPoints[j][0]);
}
PolygonTesselator.End_Contour();
}
}
PolygonTesselator.End_Polygon();
glEndList();
PolygonTesselator.TransferVerticies(layer[currentlayer].Shapes[i].OutPoints);
glGenBuffersARB(1,&layer[currentlayer].Shapes[i].VBOInt);
glBindBufferARB(GL_ARRAY_BUFFER_ARB,layer[currentlayer].Shapes[i].VBOInt);
glBufferDataARB(GL_ARRAY_BUFFER_ARB,sizeof(GLfloat) * layer[currentlayer].Shapes[i].OutPoints.size(),
&layer[currentlayer].Shapes[i].OutPoints[0], GL_STATIC_DRAW_ARB);
InvalidateRect(controls.MainGlFrame.framehWnd,NULL,false);
}
else //run vbo
{
//glEnable(GL_TEXTURE_2D);
//glDisable(GL_TEXTURE_2D);
//glBindTexture(GL_TEXTURE_2D, texName);
glColor4f(layer[currentlayer].Shapes[i].Color.r,
layer[currentlayer].Shapes[i].Color.g,
layer[currentlayer].Shapes[i].Color.b,
layer[currentlayer].Shapes[i].Color.a);
//glColor4f(1,1,1,1);
glBindBufferARB(GL_ARRAY_BUFFER_ARB, layer[currentlayer].Shapes[i].VBOInt);
//glCallList(layer[currentlayer].Shapes[i].DisplayListInt);
glEnableClientState(GL_VERTEX_ARRAY);
glVertexPointer(2, GL_FLOAT, 0, 0);
glDrawArrays(GL_TRIANGLES, 0, layer[currentlayer].Shapes[i].OutPoints.size() / 2);
glDisableClientState(GL_VERTEX_ARRAY);
glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);
}
glDisable(GL_TEXTURE_2D);
//Draw outlines
if(layer[currentlayer].Shapes[i].Outline.OutlinePoints.size() > 4)
{
glColor4f(layer[currentlayer].Shapes[i].Outline.OutlineColor.r
,layer[currentlayer].Shapes[i].Outline.OutlineColor.g
,layer[currentlayer].Shapes[i].Outline.OutlineColor.b
,layer[currentlayer].Shapes[i].Outline.OutlineColor.a);
}
}
PolygonTesselator.End();
}
}
glPopMatrix();
//end OGL code
glFlush();
SwapBuffers(hdc);
glDisable(GL_MULTISAMPLE_ARB);
EndPaint(controls.MainGlContext.mhWnd,&ps);
}
为什么我会得到如此高的 CPU 使用率?