Tech ENABLE_GL_SHADERS_ATTRIBUTES - Added shaders for glsl version 140

(cherry picked from commit prusa3d/PrusaSlicer@76d1d4949b)

resources/shaders/140/mm_gouraud.fs

@@ -0,0 +1,90 @@
+#version 140
+
+#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(0.6985074, 0.1397015, 0.6985074);
+#define LIGHT_FRONT_DIFFUSE  (0.3 * INTENSITY_CORRECTION)
+
+#define INTENSITY_AMBIENT    0.3
+
+const vec3  ZERO    = vec3(0.0, 0.0, 0.0);
+const float EPSILON = 0.0001;
+//BBS: add grey and orange
+//const vec3 GREY = vec3(0.9, 0.9, 0.9);
+const vec3 ORANGE = vec3(0.8, 0.4, 0.0);
+const vec3 LightRed = vec3(0.78, 0.0, 0.0);
+const vec3 LightBlue = vec3(0.73, 1.0, 1.0);
+uniform vec4 uniform_color;
+
+uniform bool volume_mirrored;
+
+uniform mat4 view_model_matrix;
+uniform mat3 normal_matrix;
+
+in vec3 clipping_planes_dots;
+in vec4 model_pos;
+in vec4 world_pos;
+
+struct SlopeDetection
+{
+    bool actived;
+	 float normal_z;
+    mat3 volume_world_normal_matrix;
+};
+uniform SlopeDetection slope;
+
+void main()
+{
+    if (any(lessThan(clipping_planes_dots, ZERO)))
+        discard;
+    vec3  color = uniform_color.rgb;
+    float alpha = uniform_color.a;
+
+    vec3 triangle_normal = normalize(cross(dFdx(model_pos.xyz), dFdy(model_pos.xyz)));
+#ifdef FLIP_TRIANGLE_NORMALS
+    triangle_normal = -triangle_normal;
+#endif
+
+    if (volume_mirrored)
+        triangle_normal = -triangle_normal;
+
+    vec3 transformed_normal = normalize(slope.volume_world_normal_matrix * triangle_normal);
+     
+    if (slope.actived) {
+        if(world_pos.z<0.1&&world_pos.z>-0.1)
+         {
+              color = LightBlue;
+              alpha = 1.0;
+         }
+         else if( transformed_normal.z < slope.normal_z - EPSILON)
+        {
+            color = color * 0.5 + LightRed * 0.5;
+            alpha = 1.0;
+        }
+    }
+    // First transform the normal into camera space and normalize the result.
+    vec3 eye_normal = normalize(normal_matrix * triangle_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(eye_normal, LIGHT_TOP_DIR), 0.0);
+
+    // x = diffuse, y = specular;
+    vec2 intensity = vec2(0.0);
+    intensity.x = INTENSITY_AMBIENT + NdotL * LIGHT_TOP_DIFFUSE;
+    vec3 position = (view_model_matrix * model_pos).xyz;
+    intensity.y = LIGHT_TOP_SPECULAR * pow(max(dot(-normalize(position), reflect(-LIGHT_TOP_DIR, eye_normal)), 0.0), LIGHT_TOP_SHININESS);
+
+    // Perform the same lighting calculation for the 2nd light source (no specular applied).
+    NdotL = max(dot(eye_normal, LIGHT_FRONT_DIR), 0.0);
+    intensity.x += NdotL * LIGHT_FRONT_DIFFUSE;
+
+    gl_FragColor = vec4(vec3(intensity.y) + color * intensity.x, alpha);
+}