Strange behavior from osgText

[marcoma9023]

Hi,

I created a widget consisting of several ogsText and an image.

My problem is that when I move the camera, sometimes the white text turns gray.

Below is the code:

#include "pch.h"
#include "Label3DWidget.h"

#include <osgEarth/ShaderGenerator>
#include <osgEarth/Lighting>
#include <osgEarthAnnotation/AnnotationUtils>
#include <osgEarthAnnotation/AnnotationRegistry>
#include <osgEarthAnnotation/BboxDrawable>

#include <osg/Depth>

namespace
{
	const char* iconVS =
		"#version " GLSL_VERSION_STR "\n"
		"out vec2 oe_PlaceNode_texcoord; \n"
		"void oe_PlaceNode_icon_VS(inout vec4 vertex) \n"
		"{ \n"
		"    oe_PlaceNode_texcoord = gl_MultiTexCoord0.st; \n"
		"} \n";

	const char* iconFS =
		"#version " GLSL_VERSION_STR "\n"
		"in vec2 oe_PlaceNode_texcoord; \n"
		"uniform sampler2D oe_PlaceNode_tex; \n"
		"void oe_PlaceNode_icon_FS(inout vec4 color) \n"
		"{ \n"
		"    color = texture(oe_PlaceNode_tex, oe_PlaceNode_texcoord); \n"
		"} \n";
}

Label3DWidget::Label3DWidget() : osgEarth::Annotation::AnnotationNode() {
	
	initStateSet();

	init();

	setBlackBackground();
}

void Label3DWidget::setBlackBackground() {
	osg::BoundingBox combinedBoundingBox;

	if (_flagDrawable) {
		combinedBoundingBox.expandBy(_flagDrawable->getBoundingBox());
	}
	if (_mainTextDrawable) {
		combinedBoundingBox.expandBy(_mainTextDrawable->getBoundingBox());
	}

	backgroundQuad = new osg::Geometry();
	vertices = new osg::Vec3Array(4);
	vertices->setDataVariance(osg::Object::DYNAMIC);

	float xCenter = (combinedBoundingBox.xMin() + combinedBoundingBox.xMax()) / 2.0f;
	float yCenter = (combinedBoundingBox.yMin() + combinedBoundingBox.yMax()) / 2.0f;

	float width = 200.0f;
	float height = 40.0f; // Desired height of the black background
	float zOffset = -0.01f; // Offset to ensure background is behind

	int xPadding = 5;

	(*vertices)[0].set(combinedBoundingBox.xMin() - xPadding, yCenter - height / 2.0f, combinedBoundingBox.zMin() + zOffset);
	(*vertices)[1].set(combinedBoundingBox.xMax() + xPadding, yCenter - height / 2.0f, combinedBoundingBox.zMin() + zOffset);
	(*vertices)[2].set(combinedBoundingBox.xMax() + xPadding, yCenter + height / 2.0f, combinedBoundingBox.zMin() + zOffset);
	(*vertices)[3].set(combinedBoundingBox.xMin() - xPadding, yCenter + height / 2.0f, combinedBoundingBox.zMin() + zOffset);

	backgroundQuad->setVertexArray(vertices);
	backgroundQuad->setDataVariance(osg::Object::DYNAMIC);
	//backgroundQuad->setCullingActive(false);

	osg::ref_ptr<osg::Vec4Array> colors = new osg::Vec4Array(1);
	(*colors)[0].set(0.0f, 0.0f, 0.0f, 0.6f);
	backgroundQuad->setColorArray(colors, osg::Array::BIND_OVERALL);

	backgroundQuad->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS, 0, 4));

	osg::ref_ptr <osg::StateSet> stateSet = backgroundQuad->getOrCreateStateSet();
	stateSet->setMode(GL_BLEND, osg::StateAttribute::ON);
	stateSet->setRenderingHint(osg::StateSet::TRANSPARENT_BIN);

	_geode->insertChild(0, backgroundQuad);
}

void Label3DWidget::updateBlackBackground() {
	osg::BoundingBox combinedBoundingBox = getCombinedBBox();

	float xCenter = (combinedBoundingBox.xMin() + combinedBoundingBox.xMax()) / 2.0f;
	float yCenter = (combinedBoundingBox.yMin() + combinedBoundingBox.yMax()) / 2.0f;

	float combinedHeight = combinedBoundingBox.yMax() - combinedBoundingBox.yMin();

	float height = combinedHeight;
	float zOffset = -0.05f;
	int xPadding = 5;
	int yPadding = 5;
	if (_flagImage.valid()) {
		(*vertices)[0].set(combinedBoundingBox.xMin() - xPadding, (yCenter - height / 2.0f) - yPadding, combinedBoundingBox.zMin() + zOffset);
		(*vertices)[1].set(combinedBoundingBox.xMax() + xPadding, (yCenter - height / 2.0f) - yPadding, combinedBoundingBox.zMin() + zOffset);
		(*vertices)[2].set(combinedBoundingBox.xMax() + xPadding, (yCenter + height / 2.0f) - yPadding, combinedBoundingBox.zMin() + zOffset);
		(*vertices)[3].set(combinedBoundingBox.xMin() - xPadding, (yCenter + height / 2.0f) - yPadding, combinedBoundingBox.zMin() + zOffset);
	}
	else {
		(*vertices)[0].set(combinedBoundingBox.xMin() - xPadding, (yCenter - height / 2.0f) - yPadding, combinedBoundingBox.zMin() + zOffset);
		(*vertices)[1].set(combinedBoundingBox.xMax() + xPadding, (yCenter - height / 2.0f) - yPadding, combinedBoundingBox.zMin() + zOffset);
		(*vertices)[2].set(combinedBoundingBox.xMax() + xPadding, (yCenter + height / 2.0f) + yPadding, combinedBoundingBox.zMin() + zOffset);
		(*vertices)[3].set(combinedBoundingBox.xMin() - xPadding, (yCenter + height / 2.0f) + yPadding, combinedBoundingBox.zMin() + zOffset);
	}

	vertices->dirty();
	backgroundQuad->dirtyBound();
	backgroundQuad->dirtyGLObjects();
}

void Label3DWidget::initStateSet() {
	osgEarth::ShaderGenerator::setIgnoreHint(this, true);

	_geodeStateSet = new osg::StateSet();

	osgEarth::Annotation::ScreenSpaceLayout::activate(_geodeStateSet.get());
	osgEarth::ScreenSpaceLayout::setDeclutteringEnabled(true);
	osgEarth::ScreenSpaceLayoutOptions options;
	options.minAnimationAlpha() = 0.0;
	options.minAnimationScale() = 0.0;
	osgEarth::ScreenSpaceLayout::setOptions(options);

	// completely disable depth buffer
	_geodeStateSet->setAttributeAndModes(new osg::Depth(osg::Depth::ALWAYS, 0, 1, false), osg::StateAttribute::ON | osg::StateAttribute::PROTECTED);

	// Disable lighting for place nodes by default
	_geodeStateSet->setDefine(OE_LIGHTING_DEFINE, osg::StateAttribute::OFF | osg::StateAttribute::PROTECTED);

	s_imageStateSet = _imageStateSet = new osg::StateSet();
	osgEarth::Annotation::VirtualProgram* vp = osgEarth::Annotation::VirtualProgram::getOrCreate(_imageStateSet.get());
	vp->setName("PlaceNode::imageStateSet");
	vp->setFunction("oe_PlaceNode_icon_VS", iconVS, osgEarth::ShaderComp::LOCATION_VERTEX_MODEL);
	vp->setFunction("oe_PlaceNode_icon_FS", iconFS, osgEarth::ShaderComp::LOCATION_FRAGMENT_COLORING);
	_imageStateSet->addUniform(new osg::Uniform("oe_PlaceNode_tex", 0));
	_imageStateSet->setMode(GL_BLEND, osg::StateAttribute::ON);
	_imageStateSet->setRenderingHint(osg::StateSet::TRANSPARENT_BIN);
}

void Label3DWidget::init() {
	_geode = new osg::Group();
	_geode->setCullingActive(false);
	_geode->setStateSet(_geodeStateSet.get());
	_geode->setDataVariance(osg::Object::DYNAMIC);
	_geode->setComputeBoundingSphereCallback(new osgEarth::Annotation::ControlPointCallback());

	addChild(_geode);

	osg::BoundingBox imageBox(0, 0, 0, 0, 0, 0);

	/*Flag Image*/
	if (_flagImage.get())
	{
		double scale = 2.5;
		double s = scale * _flagImage->s();
		double t = scale * _flagImage->t();
		double heading = 0.0;

		osg::Vec2s offset;
		offset.set(0, t / 2.0);

		_flagDrawable = osgEarth::Annotation::AnnotationUtils::createImageGeometry(_flagImage.get(), offset, 0, heading, scale);
		if (_flagDrawable)
		{
			imageVertices = (osg::Vec3Array*)_flagDrawable->getVertexArray();

			_flagDrawable->getOrCreateStateSet()->merge(*_imageStateSet.get());
			_flagDrawable->setCullingActive(false);
			osg::ref_ptr <osg::StateSet> stateSet = _flagDrawable->getOrCreateStateSet();
			stateSet->setMode(GL_BLEND, osg::StateAttribute::ON);
			stateSet->setRenderingHint(osg::StateSet::TRANSPARENT_BIN);
			_geode->addChild(_flagDrawable);

			imageBox = _flagDrawable->getBoundingBox();
		}
	}

	osg::BoundingBox textBoxWithOffset = imageBox;

	if (_flagImage.valid())
	{
		osg::ref_ptr <osgEarth::Annotation::TextSymbol> textSymbol = _style.getOrCreate<osgEarth::Annotation::TextSymbol>();
		textSymbol->size() = 18;
		textSymbol->alignment() = textSymbol->ALIGN_LEFT_CENTER;

		textBoxWithOffset.xMin() += 10;
		textBoxWithOffset.xMax() += 10;
	}

	_mainTextDrawable = osgEarth::Annotation::AnnotationUtils::createTextDrawable(_mainText, _style.get<osgEarth::Annotation::TextSymbol>(), textBoxWithOffset);
	_mainTextDrawable->setDataVariance(osg::Object::DYNAMIC);
	_mainTextDrawable->getOrCreateStateSet()->setMode(GL_BLEND, osg::StateAttribute::ON);
	_mainTextDrawable->getOrCreateStateSet()->setMode(GL_DEPTH_TEST, osg::StateAttribute::OFF);
	_mainTextDrawable->getOrCreateStateSet()->setRenderingHint(osg::StateSet::TRANSPARENT_BIN);
	_mainTextDrawable->getOrCreateStateSet()->setDefine(OE_LIGHTING_DEFINE, osg::StateAttribute::OFF | osg::StateAttribute::PROTECTED);

	if (_mainTextDrawable)_geode->addChild(_mainTextDrawable);

	float distanceBelow = 10.0f;
	
	osg::BoundingBox secondBoxWithOffset;
	if (_flagImage.valid()) {
		float imageBoxHeight = imageBox.yMax() - imageBox.yMin();
		secondBoxWithOffset = imageBox;
		secondBoxWithOffset.yMin() = imageBox.yMin() - imageBoxHeight - distanceBelow;
		secondBoxWithOffset.yMax() = imageBox.yMin() - distanceBelow;
	}else{
		secondBoxWithOffset = _mainTextDrawable->computeBoundingBox();
		secondBoxWithOffset.yMin() = secondBoxWithOffset.yMin() - distanceBelow;
		secondBoxWithOffset.yMax() = secondBoxWithOffset.yMin() - distanceBelow;
	}

	_secondTextDrawable = osgEarth::Annotation::AnnotationUtils::createTextDrawable("SECOND", _style.get<osgEarth::Annotation::TextSymbol>(), secondBoxWithOffset);
	_secondTextDrawable->setDataVariance(osg::Object::DYNAMIC);
	_secondTextDrawable->getOrCreateStateSet()->setMode(GL_BLEND, osg::StateAttribute::ON);
	_secondTextDrawable->getOrCreateStateSet()->setMode(GL_DEPTH_TEST, osg::StateAttribute::OFF);
	_secondTextDrawable->getOrCreateStateSet()->setRenderingHint(osg::StateSet::TRANSPARENT_BIN);
	_secondTextDrawable->getOrCreateStateSet()->setDefine(OE_LIGHTING_DEFINE, osg::StateAttribute::OFF | osg::StateAttribute::PROTECTED);

	if (_secondTextDrawable)_geode->addChild(_secondTextDrawable);

	osg::BoundingBox thirdTextBoxWithOffset = _secondTextDrawable->computeBoundingBox();
	thirdTextBoxWithOffset.xMin() += 10;
	thirdTextBoxWithOffset.xMax() += 10;

	_thirdTextDrawable = osgEarth::Annotation::AnnotationUtils::createTextDrawable("THIRD", _style.get<osgEarth::Annotation::TextSymbol>(), thirdTextBoxWithOffset);
	_thirdTextDrawable->setDataVariance(osg::Object::DYNAMIC);
	_thirdTextDrawable->getOrCreateStateSet()->setMode(GL_BLEND, osg::StateAttribute::ON);
	_thirdTextDrawable->getOrCreateStateSet()->setMode(GL_DEPTH_TEST, osg::StateAttribute::OFF);
	_thirdTextDrawable->getOrCreateStateSet()->setRenderingHint(osg::StateSet::TRANSPARENT_BIN);
	_thirdTextDrawable->getOrCreateStateSet()->setDefine(OE_LIGHTING_DEFINE, osg::StateAttribute::OFF | osg::StateAttribute::PROTECTED);

	if (_thirdTextDrawable)_geode->addChild(_thirdTextDrawable);

	setStyle(_style);
}

osg::BoundingBox Label3DWidget::getCombinedBBox() {
	osg::BoundingBox combinedBoundingBox;

	if (_flagDrawable) {
		combinedBoundingBox.expandBy(_flagDrawable->computeBoundingBox());
	}
	if (_mainTextDrawable) {
		combinedBoundingBox.expandBy(_mainTextDrawable->computeBoundingBox());
	}
	if (_secondTextDrawable) {
		combinedBoundingBox.expandBy(_secondTextDrawable->computeBoundingBox());
	}
	if (_thirdTextDrawable) {
		combinedBoundingBox.expandBy(_thirdTextDrawable->computeBoundingBox());
	}

	return combinedBoundingBox;
}

void Label3DWidget::setMainText(string text) {
	_mainText = text;
	if (_mainTextDrawable && text != "" && text != " ")
	{
		osg::BoundingBox beforeBBox = getCombinedBBox();
		double beforeWidth = (beforeBBox.xMax() - beforeBBox.xMin()) + 10;

		osg::ref_ptr <osgEarth::Annotation::TextSymbol> symbol = _style.getOrCreate<osgEarth::Annotation::TextSymbol>();
		osgText::String::Encoding text_encoding = osgText::String::ENCODING_UNDEFINED;
		if (symbol && symbol->encoding().isSet())
		{
			text_encoding = osgEarth::Annotation::AnnotationUtils::convertTextSymbolEncoding(symbol->encoding().value());
		}

		_mainTextDrawable->setText(text, text_encoding);

		updateWidgetSize(beforeWidth);
	}
}

void Label3DWidget::setSecondText(string text) {
	_secondText = text;

	if (_secondTextDrawable && text != "" && text != " ")
	{
		osg::BoundingBox beforeBBox = getCombinedBBox();
		double beforeWidth = (beforeBBox.xMax() - beforeBBox.xMin()) + 10;

		osg::ref_ptr <osgEarth::Annotation::TextSymbol> symbol = _style.getOrCreate<osgEarth::Annotation::TextSymbol>();
		osgText::String::Encoding text_encoding = osgText::String::ENCODING_UNDEFINED;
		if (symbol && symbol->encoding().isSet())
		{
			text_encoding = osgEarth::Annotation::AnnotationUtils::convertTextSymbolEncoding(symbol->encoding().value());
		}

		_secondTextDrawable->setText(text, text_encoding);

		updateWidgetSize(beforeWidth);
	}
}

void Label3DWidget::setThirdText(string text) {
	_thirdText = text;

	if (_thirdTextDrawable && text != "" && text != " ")
	{
		osg::BoundingBox beforeBBox = getCombinedBBox();
		double beforeWidth = (beforeBBox.xMax() - beforeBBox.xMin()) + 10;

		osg::ref_ptr <osgEarth::Annotation::TextSymbol> symbol = _style.getOrCreate<osgEarth::Annotation::TextSymbol>();
		osgText::String::Encoding text_encoding = osgText::String::ENCODING_UNDEFINED;
		if (symbol && symbol->encoding().isSet())
		{
			text_encoding = osgEarth::Annotation::AnnotationUtils::convertTextSymbolEncoding(symbol->encoding().value());
		}

		_thirdTextDrawable->setText(text, text_encoding);

		updateWidgetSize(beforeWidth);
	}
}

string Label3DWidget::getMainText() {
	return _mainText;
}

void Label3DWidget::updateWidgetSize(double beforeWidth) {
	
	osg::BoundingBox afterBBox = getCombinedBBox();
	double afterWidth = (afterBBox.xMax() - afterBBox.xMin()) + 10;

	if (_mainTextDrawable && _flagDrawable)
	{
		if (imageVertices) {
			(*imageVertices)[0].set(-(afterWidth / 2) - 0, 0, 0);
			(*imageVertices)[1].set(-(afterWidth / 2) + _imageSize, 0, 0);
			(*imageVertices)[2].set(-(afterWidth / 2) + _imageSize, _imageSize, 0);
			(*imageVertices)[3].set(-(afterWidth / 2) - 0, _imageSize, 0);
			imageVertices->dirty();
		}

		if (_flagDrawable != NULL) {
			_mainTextDrawable->setPosition(osg::Vec3(_flagDrawable->computeBoundingBox().xMax() + 10, 20, 0));

			float distanceBelow = 10.0f;
			
			float imageBoxHeight = _flagDrawable->computeBoundingBox().yMax() - _flagDrawable->computeBoundingBox().yMin();
			osg::BoundingBox secondBoxWithOffset = _flagDrawable->computeBoundingBox();
			secondBoxWithOffset.yMin() = _flagDrawable->computeBoundingBox().yMin() - imageBoxHeight - distanceBelow;
			secondBoxWithOffset.yMax() = _flagDrawable->computeBoundingBox().yMin() - distanceBelow;

			_secondTextDrawable->setPosition(osg::Vec3(-(afterWidth / 2), secondBoxWithOffset.yMax(), 0));

			_thirdTextDrawable->setPosition(osg::Vec3(_secondTextDrawable->computeBoundingBox().xMax() + 10, secondBoxWithOffset.yMax(), 0));
		}
	}
	else {
		_mainTextDrawable->setPosition(osg::Vec3(-(afterWidth / 2), 20, 0));
	
		double distanceBelow = 10.0;
	
		osg::BoundingBox secondBoxWithOffset = _mainTextDrawable->computeBoundingBox();
		secondBoxWithOffset.yMin() = secondBoxWithOffset.yMin() - distanceBelow;
		secondBoxWithOffset.yMax() = secondBoxWithOffset.yMin() - distanceBelow;
	
		_secondTextDrawable->setPosition(osg::Vec3(-(afterWidth / 2), secondBoxWithOffset.yMax(), 0));
	
		_thirdTextDrawable->setPosition(osg::Vec3(_secondTextDrawable->computeBoundingBox().xMax() + 10, secondBoxWithOffset.yMax(), 0));
	}

	updateBlackBackground();
}


void Label3DWidget::setFlagImage(osg::ref_ptr <osg::Image> image) {
	if (_flagImage != image)
	{
		_flagImage = image;

		osg::BoundingBox beforeBBox = getCombinedBBox();
		double beforeWidth = (beforeBBox.xMax() - beforeBBox.xMin()) + 10;

		removeChild(_geode);
		_geode = NULL;

		init();
		setBlackBackground();

		updateWidgetSize(beforeWidth);
	}
}

osg::BoundingBox Label3DWidget::getWidgetBBox() {

	return backgroundQuad->computeBoundingBox();
}

I can't figure out where the problem lies.

Regards

[marcoma9023]

aMAt0vM3rQ.mp4

[gwaldron]

Just a guess, but does it happen without the background quad? Maybe there's a Z sorting issue?