line segment shaders added

Author: vicrucann

src/cherish/Shaders/LineSegment.frag

@@ -0,0 +1,33 @@
+#version 330
+
+uniform bool IsFogged;
+uniform float FogMin;
+uniform float FogMax;
+uniform vec4 CameraEye;
+uniform vec4 FogColor;
+
+in VertexData{
+    vec4 mColor;
+    vec4 mVertex; // to calculate distance to camera eye
+} VertexIn;
+
+float getFogFactor(float d)
+{
+    if (d>=FogMax) return 1;
+    if (d<=FogMin) return 0;
+
+    return 1 - (FogMax - d) / (FogMax - FogMin);
+}
+
+void main(void)
+{
+    vec4 color = VertexIn.mColor;
+    if (IsFogged){
+        float d = distance(CameraEye, VertexIn.mVertex);
+        float alpha = getFogFactor(d);
+        color = mix(color, FogColor, alpha);
+    }
+
+    gl_FragColor = color;
+            //vec4(VertexIn.mColor.rgb, alpha);
+}

src/cherish/Shaders/LineSegment.vert

@@ -0,0 +1,19 @@
+#version 330
+
+uniform mat4 ModelViewProjectionMatrix;
+uniform mat4 CanvasMatrix;
+
+layout(location = 0) in vec4 Vertex;
+layout(location = 1) in vec4 Color;
+
+out VertexData{
+    vec4 mColor;
+    vec4 mVertex; // to calculate distance to camera eye
+} VertexOut;
+
+void main(void)
+{
+    VertexOut.mColor = Color;
+    VertexOut.mVertex = CanvasMatrix * Vertex;
+    gl_Position = ModelViewProjectionMatrix * Vertex;
+}