Added class GCodeViewer -> basic render of gcode toolpaths using dedicated shaders

resources/shaders/toolchanges.fs

@@ -0,0 +1,45 @@
+#version 110
+
+#define INTENSITY_AMBIENT    0.3
+#define INTENSITY_CORRECTION 0.6
+
+// normalized values for (-0.6/1.31, 0.6/1.31, 1./1.31)
+const vec3 LIGHT_TOP_DIR = vec3(-0.4574957, 0.4574957, 0.7624929);
+#define LIGHT_TOP_DIFFUSE    (0.8 * INTENSITY_CORRECTION)
+#define LIGHT_TOP_SPECULAR   (0.125 * INTENSITY_CORRECTION)
+#define LIGHT_TOP_SHININESS  20.0
+
+// normalized values for (1./1.43, 0.2/1.43, 1./1.43)
+const vec3 LIGHT_FRONT_DIR = vec3(0.0, 0.0, 1.0);
+#define LIGHT_FRONT_DIFFUSE  (0.3 * INTENSITY_CORRECTION)
+
+uniform vec4 uniform_color;
+
+varying vec3 eye_position;
+varying vec3 eye_normal;
+//varying float world_normal_z;
+
+// x = tainted, y = specular;
+vec2 intensity;
+
+void main()
+{
+    vec3 normal = normalize(eye_normal);
+
+    // Compute the cos of the angle between the normal and lights direction. The light is directional so the direction is constant for every vertex.
+    // Since these two are normalized the cosine is the dot product. We also need to clamp the result to the [0,1] range.
+    float NdotL = max(dot(normal, LIGHT_TOP_DIR), 0.0);
+
+    intensity.x = INTENSITY_AMBIENT + NdotL * LIGHT_TOP_DIFFUSE;
+    intensity.y = LIGHT_TOP_SPECULAR * pow(max(dot(-normalize(eye_position), reflect(-LIGHT_TOP_DIR, normal)), 0.0), LIGHT_TOP_SHININESS);
+
+    // Perform the same lighting calculation for the 2nd light source (no specular applied).
+    NdotL = max(dot(normal, LIGHT_FRONT_DIR), 0.0);
+    intensity.x += NdotL * LIGHT_FRONT_DIFFUSE;    
+
+//    // darkens fragments whose normal points downward
+//    if (world_normal_z < 0.0)
+//        intensity.x *= (1.0 + world_normal_z * (1.0 - INTENSITY_AMBIENT));
+
+    gl_FragColor = vec4(vec3(intensity.y, intensity.y, intensity.y) + uniform_color.rgb * intensity.x, uniform_color.a);
+}