抱歉，如果这是很多代码，我只是不确定你们到底需要什么来解决我的问题。我知道总线错误或多或少对应于我的主要方法中的堆栈溢出，但我不完全理解为什么会发生这种情况。我有一个填充了数百万个自定义三角形对象的向量，我正在尝试处理这些对象以绘制二维图片。这是我的代码：
vtkImageData *image = NewImage(1786, 1344);
unsigned char *buffer =
(unsigned char *) image->GetScalarPointer(0,0,0);
int npixels = 1786*1344;
for (int i = 0 ; i < npixels*3 ; i++)
buffer[i] = 0;
std::vector<Triangle> triangles = GetTriangles();
Screen *screen = new Screen;
screen->buffer = buffer;
screen->width = 1786;
screen->height = 1344;
double leftEnd, rightEnd;
int highIndex, leftIndex, rightIndex, bottomIndex, midIndex;
for(std::vector<Triangle>::iterator it = triangles.begin(); it != triangles.end(); ++it)
{
// Get this triangle
Triangle current = *it;
Triangle curr2;
char triangleType = current.whichTriangle();
// It's a flat-bottom triangle
if(triangleType == 'b'){
highIndex = current.getFlatMidIndex();
bottomIndex = current.getFlatLeftIndex();
// It's a flat-top traingle
}else if(triangleType == 'u'){
highIndex = current.getFlatLeftIndex();
bottomIndex = current.getFlatMidIndex();
//It's an arbitrary triangle
}else{
// Make two triangles, with new coordinates
curr2.X[0] = current.X[current.getArbLowIndex()];
curr2.Y[0] = current.Y[current.getArbLowIndex()];
curr2.X[1] = current.X[current.getArbMidIndex()];
curr2.Y[1] = current.Y[current.getArbMidIndex()];
curr2.X[2] = splitTriangle(current, curr2.Y[1]);
curr2.Y[2] = current.Y[current.getArbMidIndex()];
int currLowIndex = current.getArbLowIndex();
current.X[currLowIndex] = curr2.X[2];
current.Y[currLowIndex] = curr2.Y[2];
highIndex = current.getFlatMidIndex();
bottomIndex = current.getFlatLeftIndex();
}
//perform the scan-line alg on this triangle
for(double i = ceil441(current.Y[bottomIndex]); i <= floor441(current.Y[highIndex]); i++)
{
leftEnd = calcLeftEnd(current, i, i);
rightEnd = calcRightEnd(current, i, i);
// If this triangle extends past the left border, set it's left edge to 0
if(leftEnd < 0){
leftEnd = 0;
}
// If this triangle extends past the left border, set it's right edge to 999
if(rightEnd > (screen->width - 1)){
rightEnd = screen->width - 1;
}
for(double j = ceil441(leftEnd); j <= floor441(rightEnd); j++)
{
// Pixels to color will be ((Y * 50 + X) * 3); this will account
// for the fact that the buffer is one long array, not a
// 2D array like we think of it
int pixel = ((i * screen->width) + j) * 3;
// Make sure we don't segfault
if(pixel < (npixels * 3)){
screen->buffer[pixel] = current.color[0];
screen->buffer[pixel + 1] = current.color[1];
screen->buffer[pixel + 2] = current.color[2];
}
}
}
if(triangleType == 'a'){
highIndex = curr2.getFlatLeftIndex();
bottomIndex = curr2.getFlatMidIndex();
for(double i = ceil441(curr2.Y[bottomIndex]); i <= floor441(curr2.Y[highIndex]); i++)
{
leftEnd = calcLeftEnd(curr2, i, i);
rightEnd = calcRightEnd(curr2, i, i);
// If this triangle extends past the left border, set it's left edge to 0
if(leftEnd < 0){
leftEnd = 0;
}
// If this triangle extends past the left border, set it's right edge to 999
if(rightEnd > (screen->width - 1)){
rightEnd = screen->width - 1;
}
for(double j = ceil441(leftEnd); j <= floor441(rightEnd); j++)
{
// Pixels to color will be ((Y * 50 + X) * 3); this will account
// for the fact that the buffer is one long array, not a
// 2D array like we think of it
int pixel = ((i * screen->width) + j) * 3;
// Make sure we don't segfault
if(pixel < (npixels * 3)){
screen->buffer[pixel] = current.color[0];
screen->buffer[pixel + 1] = current.color[1];
screen->buffer[pixel + 2] = current.color[2];
}
}
}
}
}
我已经能够处理大约 200,000 个三角形，但在那之后我得到了一个总线错误。我知道我必须将其中一些代码移出我的主要方法，但我不确定哪些部分以及为什么。感谢帮助。