Extrusions: light source calculation with normals (#651)

vtm/resources/assets/shaders/extrusion_layer_ext.glsl

@@ -5,13 +5,25 @@ uniform mat4 u_mvp;
 uniform vec4 u_color[4];
 uniform int u_mode;
 uniform float u_alpha;
+uniform vec3 u_light;
 uniform float u_zlimit;
 attribute vec4 a_pos;
-attribute vec2 a_light;
+attribute vec2 a_normal;
 varying vec4 color;
 //varying float depth;
 const float ff = 255.0;
 
+/**
+ * The diffuse of surface dependent on the light position
+ *
+ * @param r_norm - the normal vector of vertex's face
+ */
+float diffuse(in vec3 r_norm) {
+  float l = dot(normalize(r_norm), normalize(u_light));
+  l = clamp((1.0 + l) / 2.0, 0.0, 1.0);
+  return(0.8 + l * 0.2);
+}
+
 void main() {
   // change height by u_alpha
   float height = a_pos.z * u_alpha;
@@ -22,30 +34,33 @@ void main() {
   //depth = gl_Position.z;
   if (u_mode == -1) {
     ;
+  } else if(u_mode >= 0 && u_mode <= 2) {
+    vec3 r_norm;
+    if (u_mode == 0) {
       // roof / depth pass
-    //    color = u_color[0] * u_alpha;
+      r_norm = vec3(0.0, 0.0, 1.0);
-  }
-  else if (u_mode == 0) {
-    //     roof / depth pass
       color = u_color[0] * u_alpha;
-  }
+      color.rgb *= diffuse(r_norm);
-  else if (u_mode == 1) {
+    } else {
+      float lightX = u_mode == 1 ? a_normal.y : a_normal.x;
+      r_norm.x = (lightX / ff) * 2.0 - 1.0;
+      // normal points y left or right (1 or -1)
+      float dir = - 1.0 + (2.0 * abs(mod(lightX, 2.0)));
+      // recreate y vector
+      r_norm.y = dir * sqrt(clamp(1.0 - (r_norm.x * r_norm.x), 0.0, 1.0));
+      r_norm.z = 0.0;
+
+      float z = (0.98 + gl_Position.z * 0.02);
+      float h = 0.9 + clamp(a_pos.z / 2000.0, 0.0, 0.1);
+      if (u_mode == 1) {
         // sides 1 - use 0xff00
-    //     scale direction to -0.5<>0.5
-    float dir = a_light.y / ff;
-    float z = (0.98 + gl_Position.z * 0.02);
-    float h = 0.9 + clamp(a_pos.z / 2000.0, 0.0, 0.1);
         color = u_color[1];
-    color.rgb *= (0.8 + dir * 0.2) * z * h;
+      } else {
-    color *= u_alpha;
-  }
-  else if (u_mode == 2) {
         // sides 2 - use 0x00ff
-    float dir = a_light.x / ff;
-    float z = (0.98 + gl_Position.z * 0.02);
-    float h = 0.9 + clamp(a_pos.z / 2000.0, 0.0, 0.1);
         color = u_color[2];
-    color.rgb *= (0.8 + dir * 0.2) * z * h;
+      }
+      color.rgb *= diffuse(r_norm) * z * h;
+    }
     color *= u_alpha;
   }
   else if (u_mode == 3) {

vtm/resources/assets/shaders/extrusion_layer_mesh.glsl

@@ -4,8 +4,9 @@ precision highp float;
 uniform mat4 u_mvp;
 uniform vec4 u_color;
 uniform float u_alpha;
+uniform vec3 u_light;
 attribute vec4 a_pos;
-attribute vec2 a_light;
+attribute vec2 a_normal;
 varying vec4 color;
 
 void main() {
@@ -14,25 +15,27 @@ void main() {
   pos.z *= u_alpha;
   gl_Position = u_mvp * pos;
   // normalize face x/y direction
-  vec2 enc = (a_light / 255.0);
+  vec2 enc = (a_normal / 255.0);
-  vec2 fenc = enc * 4.0 - 2.0;
+
-  float f = dot(fenc, fenc);
-  float g = sqrt(1.0 - f / 4.0);
   vec3 r_norm;
-  r_norm.xy = fenc * g;
+  // 1² - |xy|² = |z|²
-  r_norm.z = 1.0 - f / 2.0;
+  r_norm.xy = enc * 2.0 - 1.0;
   // normal points up or down (1,-1)
-  ////    float dir = 1.0 - (2.0 * abs(mod(a_light.x,2.0)));
+  float dir = - 1.0 + (2.0 * abs(mod(a_normal.x, 2.0)));
-  //     recreate face normal vector
+  // recreate z vector
-  ///    vec3 r_norm = vec3(n.xy, dir * (1.0 - length(n.xy)));
+  r_norm.z = dir * sqrt(clamp(1.0 - (r_norm.x * r_norm.x + r_norm.y * r_norm.y), 0.0, 1.0));
-  vec3 light_dir = normalize(vec3(0.2, 0.2, 1.0));
+  r_norm = normalize(r_norm);
-  float l = dot(r_norm, light_dir) * 0.8;
 
-  light_dir = normalize(vec3(-0.2, -0.2, 1.0));
+  float l = dot(r_norm, normalize(u_light));
-  l += dot(r_norm, light_dir) * 0.2;
 
-  //  l = (l + (1.0 - r_norm.z))*0.5;
+  //l *= 0.8
-  l = 0.4 + l * 0.6;
+  //vec3 opp_light_dir = normalize(vec3(-u_light.xy, u_light.z));
+  //l += dot(r_norm, opp_light_dir) * 0.2;
+
+  // [-1,1] to range [0,1]
+  l = (1.0 + l) / 2.0;
+
+  l = 0.75 + l * 0.25;
 
   // extreme fake-ssao by height
   l += (clamp(a_pos.z / 2048.0, 0.0, 0.1) - 0.05);

vtm/src/org/oscim/renderer/ExtrusionRenderer.java

@@ -2,7 +2,7 @@
  * Copyright 2013 Hannes Janetzek
  * Copyright 2017 Izumi Kawashima
  * Copyright 2017 devemux86
- * Copyright 2018 Gustl22
+ * Copyright 2018-2019 Gustl22
  *
  * This file is part of the OpenScienceMap project (http://www.opensciencemap.org).
  *
@@ -45,6 +45,7 @@ public abstract class ExtrusionRenderer extends LayerRenderer {
     protected float mAlpha = 1;
 
     private float mZLimit = Float.MAX_VALUE;
+    private float[] mLightPos = new float[]{0.3f, 0.3f, 1f};
 
     public ExtrusionRenderer(boolean mesh, boolean translucent) {
         mMesh = mesh;
@@ -58,9 +59,9 @@ public abstract class ExtrusionRenderer extends LayerRenderer {
         int aPos;
 
         /**
-         * The light indicator of vertex's face as attribute.
+         * The normal of vertex's face as attribute.
          */
-        int aLight;
+        int aNormal;
 
         /**
          * The alpha value (e.g. for fading animation) as uniform.
@@ -72,6 +73,11 @@ public abstract class ExtrusionRenderer extends LayerRenderer {
          */
         int uColor;
 
+        /**
+         * The lights position vector as uniform.
+         */
+        int uLight;
+
         /**
          * The shader render mode as uniform.
          * <p>
@@ -104,7 +110,8 @@ public abstract class ExtrusionRenderer extends LayerRenderer {
             uMode = getUniform("u_mode");
             uZLimit = getUniform("u_zlimit");
             aPos = getAttrib("a_pos");
-            aLight = getAttrib("a_light");
+            aNormal = getAttrib("a_normal");
+            uLight = getUniform("u_light");
         }
     }
 
@@ -164,6 +171,7 @@ public abstract class ExtrusionRenderer extends LayerRenderer {
         gl.depthFunc(GL.LESS);
         gl.uniform1f(s.uAlpha, mAlpha);
         gl.uniform1f(s.uZLimit, mZLimit);
+        GLUtils.glUniform3fv(s.uLight, 1, mLightPos);
 
         ExtrusionBuckets[] ebs = mExtrusionBucketSet;
 
@@ -199,7 +207,7 @@ public abstract class ExtrusionRenderer extends LayerRenderer {
 
         GLState.blend(true);
 
-        GLState.enableVertexArrays(s.aPos, s.aLight);
+        GLState.enableVertexArrays(s.aPos, s.aNormal);
 
         for (int i = 0; i < mBucketsCnt; i++) {
             if (ebs[i].ibo == null)
@@ -231,7 +239,7 @@ public abstract class ExtrusionRenderer extends LayerRenderer {
                 gl.vertexAttribPointer(s.aPos, 3, GL.SHORT,
                         false, RenderBuckets.SHORT_BYTES * 4, eb.getVertexOffset());
 
-                gl.vertexAttribPointer(s.aLight, 2, GL.UNSIGNED_BYTE,
+                gl.vertexAttribPointer(s.aNormal, 2, GL.UNSIGNED_BYTE,
                         false, RenderBuckets.SHORT_BYTES * 4, eb.getVertexOffset() + RenderBuckets.SHORT_BYTES * 3);
 
                 /* draw extruded outlines (mMesh == false) */

vtm/src/org/oscim/renderer/GLUtils.java

@@ -283,6 +283,13 @@ public class GLUtils {
         color[2] = FastMath.clampN((float) (p + (b - p) * change));
     }
 
+    public static void glUniform3fv(int location, int count, float[] val) {
+        FloatBuffer buf = MapRenderer.getFloatBuffer(count * 3);
+        buf.put(val);
+        buf.flip();
+        gl.uniform3fv(location, count, buf);
+    }
+
     public static void glUniform4fv(int location, int count, float[] val) {
         FloatBuffer buf = MapRenderer.getFloatBuffer(count * 4);
         buf.put(val);

vtm/src/org/oscim/renderer/bucket/ExtrusionBucket.java

@@ -1,6 +1,6 @@
 /*
  * Copyright 2012, 2013 Hannes Janetzek
- * Copyright 2017 Gustl22
+ * Copyright 2017-2019 Gustl22
  *
  * This file is part of the OpenScienceMap project (http://www.opensciencemap.org).
  *
@@ -68,7 +68,7 @@ public class ExtrusionBucket extends RenderBucket {
 
     private KeyMap<Vertex> mVertexMap;
 
-    //private static final int NORMAL_DIR_MASK = 0xFFFFFFFE;
+    private static final int NORMAL_DIR_MASK = 0xFFFFFFFE;
     //private int numIndexHits = 0;
 
     /**
@@ -214,14 +214,9 @@ public class ExtrusionBucket extends RenderBucket {
                 double len = Math.sqrt(cx * cx + cy * cy + cz * cz);
 
                 // packing the normal in two bytes
-                //    int mx = FastMath.clamp(127 + (int) ((cx / len) * 128), 0, 0xff);
+                int mx = FastMath.clamp(127 + (int) ((cx / len) * 128), 0, 0xff);
-                //    int my = FastMath.clamp(127 + (int) ((cy / len) * 128), 0, 0xff);
+                int my = FastMath.clamp(127 + (int) ((cy / len) * 128), 0, 0xff);
-                //    short normal = (short) ((my << 8) | (mx & NORMAL_DIR_MASK) | (cz > 0 ? 1 : 0));
+                short normal = (short) ((my << 8) | (mx & NORMAL_DIR_MASK) | (cz > 0 ? 1 : 0));
-
-                double p = Math.sqrt((cz / len) * 8.0 + 8.0);
-                int mx = FastMath.clamp(127 + (int) ((cx / len / p) * 128), 0, 255);
-                int my = FastMath.clamp(127 + (int) ((cy / len / p) * 128), 0, 255);
-                short normal = (short) ((my << 8) | mx);
 
                 if (key == null)
                     key = vertexPool.get();
@@ -472,10 +467,13 @@ public class ExtrusionBucket extends RenderBucket {
         /* vector from previous point */
         float ux, uy;
 
+        // Normalized normal of first point (with vy direction included)
+        // Normal of vector (x|y) is (y|-x)
         float a = (float) Math.sqrt(vx * vx + vy * vy);
-        short color1 = (short) ((1 + vx / a) * 127);
+        short mx1 = (short) ((1 + (vy / a)) * 127);
+        mx1 = (short) ((mx1 & NORMAL_DIR_MASK) | (-vx > 0 ? 1 : 0));
 
-        short fcolor = color1, color2 = 0;
+        short mxStore = mx1, mx2 = 0;
 
         short h = (short) height, mh = (short) minHeight;
 
@@ -502,7 +500,7 @@ public class ExtrusionBucket extends RenderBucket {
                 nx = points[pos + 0];
                 ny = points[pos + 1];
             } else { // if (addFace)
-                short c = (short) (color1 | fcolor << 8);
+                short c = (short) (mx1 | mxStore << 8);
                 /* add bottom and top vertex for each point */
                 vertexItems.add((short) (cx * COORD_SCALE), (short) (cy * COORD_SCALE), mh, c);
                 vertexItems.add((short) (cx * COORD_SCALE), (short) (cy * COORD_SCALE), h, c);
@@ -515,20 +513,22 @@ public class ExtrusionBucket extends RenderBucket {
             vy = ny - cy;
 
             /* set lighting (by direction) */
+            // Normal of vector (x|y) is (y|-x)
             a = (float) Math.sqrt(vx * vx + vy * vy);
-            color2 = (short) ((1 + vx / a) * 127);
+            mx2 = (short) ((1 + (vy / a)) * 127);
+            mx2 = (short) ((mx2 & NORMAL_DIR_MASK) | (-vx > 0 ? 1 : 0));
 
             short c;
             if (even == 0)
-                c = (short) (color1 | color2 << 8);
+                c = (short) (mx1 | mx2 << 8);
             else
-                c = (short) (color2 | color1 << 8);
+                c = (short) (mx2 | mx1 << 8);
 
             /* add bottom and top vertex for each point */
             vertexItems.add((short) (cx * COORD_SCALE), (short) (cy * COORD_SCALE), mh, c);
             vertexItems.add((short) (cx * COORD_SCALE), (short) (cy * COORD_SCALE), h, c);
 
-            color1 = color2;
+            mx1 = mx2;
 
             /* check if polygon is convex */
             if (convex) {