我试图理解如何使用QSGSimpleTextureNode,但是Qt文档非常模糊。我想在场景图上渲染文本,所以基本上我想要的是用所有的象形文字绘制一个纹理,然后在一个QSGSimpleTextureNode上设置这个纹理。我的想法是使用标准OpenGL代码创建纹理,并将纹理数据设置为我刚刚创建的数据。我找不到一个例子来告诉我如何做到这一点。
发布于 2015-01-05 21:07:23
我会使用QSGGeometryNode而不是QSGSimpleTextureNode。如果我没有错,就不可能在QSGSimpleTextureNode中设置纹理坐标。您可以为该QQuickItem编写自定义SpriteText并覆盖updatePaintNode:
QSGNode* SpriteText::updatePaintNode(QSGNode *old, UpdatePaintNodeData *data)
{
QSGGeometryNode* node = static_cast<QSGGeometryNode*>(old);
if (!node){
node = new QSGGeometryNode();
}
QSGGeometry *geometry = NULL;
if (!old){
geometry = new QSGGeometry(QSGGeometry::defaultAttributes_TexturedPoint2D()
,vertexCount);
node->setFlag(QSGNode::OwnsGeometry);
node->setMaterial(material); // <-- Texture with your glyphs
node->setFlag(QSGNode::OwnsMaterial);
geometry->setDrawingMode(GL_TRIANGLES);
node->setGeometry(geometry);
} else {
geometry = node->geometry();
geometry->allocate(vertexCount);
}
if (textChanged){
//For every Glyph in Text:
//Calc x + y position for glyph in texture (between 0-1)
//Create vertexes with calculated texture coordinates and calculated x coordinate
geometry->vertexDataAsTexturedPoint2D()[index].set(...);
...
node->markDirty(QSGNode::DirtyGeometry);
}
//you could start timer here which call update() methode
return node;
}
https://stackoverflow.com/questions/26718063
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