Change target when zooming to be crosshair and border with crosshair

modules/skybrowser/include/screenspaceskytarget.h

@@ -62,7 +62,7 @@ namespace openspace {
         properties::FloatProperty _showCrosshairThreshold;
         std::unique_ptr<ghoul::opengl::Texture> _texture;
 
-        UniformCache(modelTransform, viewProj, texture, showCrosshair, borderWidth, targetDimensions, borderColor) _uniformCache;
+        UniformCache(modelTransform, viewProj, texture, showCrosshair, showCrosshairInTarget, borderWidth, targetDimensions, borderColor) _uniformCache;
         GLuint _vertexArray = 0;
         GLuint _vertexBuffer = 0;
         float _fieldOfView = 100.f;

modules/skybrowser/shaders/target_fs.glsl

@@ -2,6 +2,7 @@ uniform sampler2D texture1;
 uniform float borderWidth;
 uniform vec2 targetDimensions;
 uniform bool showCrosshair;
+uniform bool showCrosshairInTarget;
 uniform vec4 borderColor;
 
 
@@ -11,8 +12,8 @@ in vec4 vs_position;
 
 float crossLine(in float _width, in float _coord) {
     float center = 0.5f;
-    float line = smoothstep(center, center+(_width/2) , _coord) -
-                 smoothstep(center-(_width/2), center, _coord);
+    float line = smoothstep(center, center+(_width/2), _coord)
+               - smoothstep(center-(_width/2), center, _coord);
     return line;
 }
 
@@ -23,16 +24,26 @@ Fragment getFragment() {
 
     float ratio = targetDimensions.y / targetDimensions.x;
 
-    // draw crosshair
-    float crossWidth = 0.1f;
-    vec3 crosshair = vec3(crossLine(crossWidth*ratio, (vs_st).x) + crossLine(crossWidth, (vs_st).y));
-
     // draw square border
-    float borderBottomLeft = step(borderWidth*ratio, vs_st.x) * step(borderWidth*ratio, (1.0)-vs_st.x);
-    float borderTopRight = step(borderWidth, vs_st.y) * step(borderWidth, (1.0)-vs_st.y);
-    vec3 border = vec3(borderBottomLeft*borderTopRight);
+    float border_bl = step(borderWidth*ratio, vs_st.x) * step(borderWidth*ratio, (1.0)-vs_st.x);
+    float border_tr = step(borderWidth, vs_st.y) * step(borderWidth, (1.0)-vs_st.y);
+    vec3 border = vec3(border_bl*border_tr);
 
-    // show crosshair or border
+    // draw crosshair inside square border
+    float crosshair_border_linewidth = 0.06f;
+    float border_crosshair_bl = step(borderWidth*ratio*4, vs_st.x) * step(borderWidth*ratio*4, (1.0)-vs_st.x);
+    float border_crosshair_tr = step(borderWidth*4, vs_st.y) * step(borderWidth*4, (1.0)-vs_st.y);
+    vec3 crosshair_small = vec3(border_crosshair_bl*border_crosshair_tr);
+    
+    vec3 crosshair_inside_border = vec3(crossLine(crosshair_small.x * crosshair_border_linewidth, (vs_st).x) 
+    + crossLine(crosshair_small.y * crosshair_border_linewidth, (vs_st).y));
+    vec3 crosshair_and_border =  (1.0 - border) + crosshair_inside_border;
+
+    // draw crosshair
+    float crosshair_linewidth = 0.14f;
+    vec3 crosshair = vec3(crossLine(crosshair_linewidth*ratio*1.1, vs_st.x) + crossLine(crosshair_linewidth, vs_st.y));
+
+    // show crosshair or border or both
     frag.color = vec4(1,1,1,1);
     frag.color.rgba = vec4(borderColor);
 
@@ -42,6 +53,13 @@ Fragment getFragment() {
             frag.color.a = 0.0;
         }
     }
+    else if(showCrosshairInTarget) {
+        frag.color.rgba = vec4(borderColor);
+        if(crosshair_and_border == vec3(0.0)) {
+            frag.color.a = 0.0;
+        }
+
+    }
     else {
         if(border == vec3(1.0)) {
             frag.color.a = 0.0;

modules/skybrowser/src/screenspaceskytarget.cpp

@@ -38,8 +38,8 @@ namespace {
         "Set the dimensions of the SkyTarget according to the SkyBrowser ratio "
     };
 
-    constexpr const std::array<const char*, 7> UniformNames = {
-        "ModelTransform", "ViewProjectionMatrix", "texture1", "showCrosshair", "borderWidth", "targetDimensions", "borderColor"
+    constexpr const std::array<const char*, 8> UniformNames = {
+        "ModelTransform", "ViewProjectionMatrix", "texture1", "showCrosshair", "showCrosshairInTarget", "borderWidth", "targetDimensions", "borderColor"
     };
 
     constexpr const openspace::properties::Property::PropertyInfo BrowserIDInfo =
@@ -77,7 +77,7 @@ namespace openspace {
         : ScreenSpaceRenderable(dictionary)
         , _targetDimensions(TargetDimensionInfo, glm::ivec2(1000.f), glm::ivec2(0.f), glm::ivec2(6000.f))
         , _skyBrowserID(BrowserIDInfo)
-        , _showCrosshairThreshold(CrosshairThresholdInfo, 2.f, 1.f, 70.f)
+        , _showCrosshairThreshold(CrosshairThresholdInfo, 0.6f, 0.1f, 70.f)
         , _borderColor(220, 220, 220)
     {
         // Handle target dimension property
@@ -221,15 +221,19 @@ namespace openspace {
         glDisable(GL_CULL_FACE);
        
         glm::mat4 modelTransform = globalRotationMatrix() * translationMatrix() * localRotationMatrix() * scaleMatrix();
-        float borderWidth = 0.002f/_scale.value();
+        float borderWidth = 0.0016f/_scale.value();
+        float showCrosshairInTargetThreshold = 2.f; // show crosshair and target when browser FOV < 2 degrees
         glm::vec2 targetDim;
         bool showCrosshair;
+        bool showCrosshairInTarget;
         _targetDimensions.value() == glm::vec2(0) ? targetDim = glm::vec2(1) : targetDim = _targetDimensions.value();
         _shader->activate();
 
+        _fieldOfView < showCrosshairInTargetThreshold && _fieldOfView > _showCrosshairThreshold ? showCrosshairInTarget = true : showCrosshairInTarget = false;
         _fieldOfView < _showCrosshairThreshold ? showCrosshair = true : showCrosshair = false;
 
         _shader->setUniform(_uniformCache.showCrosshair, showCrosshair);
+        _shader->setUniform(_uniformCache.showCrosshairInTarget, showCrosshairInTarget);
         _shader->setUniform(_uniformCache.borderWidth, borderWidth);
         _shader->setUniform(_uniformCache.targetDimensions, targetDim);
         _shader->setUniform(_uniformCache.modelTransform, modelTransform);