Make crosshair appear at all times with a fixed size

modules/skybrowser/include/screenspaceskytarget.h

@@ -82,7 +82,7 @@ public:
 
 private:
     // Properties
-    properties::FloatProperty _showCrosshairThreshold;
+    properties::FloatProperty _crossHairSize;
     properties::FloatProperty _showRectangleThreshold;
     properties::FloatProperty _lineWidth;
     properties::DoubleProperty _stopAnimationThreshold;
@@ -94,7 +94,7 @@ private:
     bool _shouldLockAfterAnimation = false;
 
     // Shader
-    UniformCache(modelTransform, viewProj, showCrosshair, showRectangle, lineWidth, 
+    UniformCache(modelTransform, viewProj, crossHairSize, showRectangle, lineWidth,
         dimensions, lineColor) _uniformCache;
     GLuint _vertexArray = 0;
     GLuint _vertexBuffer = 0;

modules/skybrowser/shaders/target_fs.glsl

@@ -27,7 +27,7 @@ in vec4 vs_position;
 
 uniform float lineWidth;
 uniform vec2 dimensions;
-uniform bool showCrosshair;
+uniform float crossHairSize;
 uniform bool showRectangle;
 uniform vec4 lineColor;
 
@@ -43,6 +43,10 @@ float createLine(float lineCenter, float lineWidth, float coord) {
   return step(startEdge, coord) - step(endEdge, coord);
 }
 
+float createFilledRectangle(float width, vec2 coord) {
+  return createLine(0.5, width, coord.x) * createLine(0.5, width, coord.y);
+}
+
 float createRectangle(float linewidthY, float ratio, vec2 coord) {
   // Calculate the widths and centers for the lines
   float linewidthX = linewidthY * ratio * VerticalThickness;
@@ -70,14 +74,11 @@ float createCrosshair(in float linewidth, in float ratio, in vec2 coord) {
 
 Fragment getFragment() {
     float ratio = dimensions.y / dimensions.x;
-    float crosshair = 0.0;
     float rectangle = 0.0;
+    float crossHairBox = createFilledRectangle(crossHairSize/dimensions.x, vs_st);
 
-    if (showCrosshair) {
-      crosshair = createCrosshair(lineWidth, ratio, vs_st);
-      float border = 1.0 - createRectangle(lineWidth * 5.0, ratio, vs_st);
-      crosshair *= border;
-    }
+    float crosshair = createCrosshair(lineWidth, ratio, vs_st);
+    crosshair *= crossHairBox;
 
     if (showRectangle) {
       rectangle = createRectangle(lineWidth, ratio, vs_st);

modules/skybrowser/src/screenspaceskytarget.cpp

@@ -40,16 +40,15 @@ namespace {
     constexpr const char* _loggerCat = "ScreenSpaceSkyTarget";
 
     constexpr const std::array<const char*, 7> UniformNames = {
-        "modelTransform", "viewProj", "showCrosshair", "showRectangle", "lineWidth", 
+        "modelTransform", "viewProj", "crossHairSize", "showRectangle", "lineWidth", 
         "dimensions", "lineColor"
     };
 
-    constexpr const openspace::properties::Property::PropertyInfo CrosshairThresholdInfo =
+    constexpr const openspace::properties::Property::PropertyInfo crossHairSizeInfo =
     {
-        "CrosshairThreshold",
-        "Crosshair Threshold",
-        "When the field of view is smaller than the crosshair threshold, a crosshair will"
-        "be rendered in the target."
+        "CrosshairSize",
+        "Crosshair Size",
+        "Determines the size of the crosshair."
     }; 
     
     constexpr const openspace::properties::Property::PropertyInfo RectangleThresholdInfo =
@@ -82,8 +81,8 @@ namespace {
     };
 
     struct [[codegen::Dictionary(ScreenSpaceSkyTarget)]] Parameters {
-        // [[codegen::verbatim(CrosshairThresholdInfo.description)]]
-        std::optional<float> crosshairThreshold;
+        // [[codegen::verbatim(crossHairSizeInfo.description)]]
+        std::optional<float> crossHairSize;
 
         // [[codegen::verbatim(RectangleThresholdInfo.description)]]
         std::optional<float> rectangleThreshold;
@@ -104,7 +103,7 @@ namespace {
 namespace openspace {
 ScreenSpaceSkyTarget::ScreenSpaceSkyTarget(const ghoul::Dictionary& dictionary)
     : ScreenSpaceRenderable(dictionary)
-    , _showCrosshairThreshold(CrosshairThresholdInfo, 4.f, 0.1f, 70.f)
+    , _crossHairSize(crossHairSizeInfo, 0.05f, 0.005f, 0.2f)
     , _showRectangleThreshold(RectangleThresholdInfo, 2.f, 0.1f, 70.f)
     , _stopAnimationThreshold(AnimationThresholdInfo, 0.0005, 0.0, 0.005)
     , _animationSpeed(AnimationSpeedInfo, 5.0, 0.1, 10.0)
@@ -113,12 +112,12 @@ ScreenSpaceSkyTarget::ScreenSpaceSkyTarget(const ghoul::Dictionary& dictionary)
 {
     // Handle target dimension property
     const Parameters p = codegen::bake<Parameters>(dictionary);
-    _showCrosshairThreshold = p.crosshairThreshold.value_or(_showCrosshairThreshold);
+    _crossHairSize = p.crossHairSize.value_or(_crossHairSize);
     _showRectangleThreshold = p.rectangleThreshold.value_or(_showRectangleThreshold);
-    _stopAnimationThreshold = p.crosshairThreshold.value_or(_stopAnimationThreshold);
+    _stopAnimationThreshold = p.crossHairSize.value_or(_stopAnimationThreshold);
     _animationSpeed = p.animationSpeed.value_or(_animationSpeed);
          
-    addProperty(_showCrosshairThreshold);
+    addProperty(_crossHairSize);
     addProperty(_showRectangleThreshold);
     addProperty(_stopAnimationThreshold);
     addProperty(_animationSpeed);
@@ -205,7 +204,6 @@ glm::ivec3 ScreenSpaceSkyTarget::borderColor() const {
 }
 
 void ScreenSpaceSkyTarget::render() {
-    bool showCrosshair = _verticalFov < _showCrosshairThreshold;
     bool showRectangle = _verticalFov > _showRectangleThreshold;
         
     glm::vec4 color = { glm::vec3(_borderColor) / 255.f, _opacity.value() };
@@ -216,10 +214,10 @@ void ScreenSpaceSkyTarget::render() {
     glDisable(GL_CULL_FACE);
 
     _shader->activate();
-    _shader->setUniform(_uniformCache.showCrosshair, showCrosshair);
+    _shader->setUniform(_uniformCache.crossHairSize, _crossHairSize);
     _shader->setUniform(_uniformCache.showRectangle, showRectangle);
     _shader->setUniform(_uniformCache.lineWidth, lineWidth);
-    _shader->setUniform(_uniformCache.dimensions, glm::vec2(_objectSize));
+    _shader->setUniform(_uniformCache.dimensions, screenSpaceDimensions());
     _shader->setUniform(_uniformCache.modelTransform, modelTransform);
     _shader->setUniform(_uniformCache.lineColor, color);
     _shader->setUniform(