Circle map style: use GL quads or GL points #122

vtm-playground/src/org/oscim/test/CircleTest.java

@@ -14,6 +14,7 @@
  */
 package org.oscim.test;
 
+import org.oscim.backend.GLAdapter;
 import org.oscim.backend.canvas.Color;
 import org.oscim.core.GeometryBuffer;
 import org.oscim.gdx.GdxMap;
@@ -73,6 +74,9 @@ public class CircleTest extends GdxMap {
     }
 
     public static void main(String[] args) {
+        // Draw circles with quads or points
+        GLAdapter.CIRCLE_QUADS = false;
+
         GdxMapApp.init();
         GdxMapApp.run(new CircleTest());
     }

vtm/resources/assets/shaders/circle_quad.glsl

@@ -0,0 +1,22 @@
+#ifdef GLES
+precision highp float;
+#endif
+uniform mat4 u_mvp;
+attribute vec2 a_pos;
+varying vec2 v_pos;
+void main() {
+    gl_Position = u_mvp * vec4(a_pos, 0.0, 1.0);
+    v_pos = a_pos;
+}
+
+$$
+
+#ifdef GLES
+precision highp float;
+#endif
+uniform vec4 u_color;
+uniform float u_scale;
+varying vec2 v_pos;
+void main() {
+    gl_FragColor = u_color;
+}

vtm/src/org/oscim/backend/GLAdapter.java

@@ -1,5 +1,6 @@
 /*
  * Copyright 2013 Hannes Janetzek
+ * Copyright 2016 devemux86
  *
  * This file is part of the OpenScienceMap project (http://www.opensciencemap.org).
  *
@@ -35,6 +36,11 @@ public class GLAdapter {
      */
     public static boolean NO_BUFFER_SUB_DATA = false;
 
+    /**
+     * Draw circles with quads or points.
+     */
+    public static boolean CIRCLE_QUADS = false;
+
     public static void init(GL gl20) {
         gl = gl20;
     }

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

@@ -36,7 +36,7 @@ public class CircleBucket extends RenderBucket {
     public CircleStyle circle;
 
     public CircleBucket(int level) {
-        super(RenderBucket.CIRCLE, true, false);
+        super(RenderBucket.CIRCLE, true, GLAdapter.CIRCLE_QUADS);
         this.level = level;
     }
 
@@ -49,16 +49,43 @@ public class CircleBucket extends RenderBucket {
         float x = geom.getPointX(0);
         float y = geom.getPointY(0);
 
-        vertexItems.add((short) (x * COORD_SCALE), (short) (y * COORD_SCALE));
+        if (GLAdapter.CIRCLE_QUADS) {
-        indiceItems.add((short) numVertices++);
+            // Create quad
-        numIndices++;
+            vertexItems.add((short) ((x + circle.radius) * COORD_SCALE), (short) ((y - circle.radius) * COORD_SCALE));
+            int ne = numVertices++;
+            vertexItems.add((short) ((x - circle.radius) * COORD_SCALE), (short) ((y - circle.radius) * COORD_SCALE));
+            int nw = numVertices++;
+            vertexItems.add((short) ((x - circle.radius) * COORD_SCALE), (short) ((y + circle.radius) * COORD_SCALE));
+            int sw = numVertices++;
+            vertexItems.add((short) ((x + circle.radius) * COORD_SCALE), (short) ((y + circle.radius) * COORD_SCALE));
+            int se = numVertices++;
+
+            indiceItems.add((short) ne);
+            numIndices++;
+            indiceItems.add((short) nw);
+            numIndices++;
+            indiceItems.add((short) sw);
+            numIndices++;
+
+            indiceItems.add((short) sw);
+            numIndices++;
+            indiceItems.add((short) se);
+            numIndices++;
+            indiceItems.add((short) ne);
+            numIndices++;
+        } else {
+            // Use point
+            vertexItems.add((short) (x * COORD_SCALE), (short) (y * COORD_SCALE));
+            indiceItems.add((short) numVertices++);
+            numIndices++;
+        }
     }
 
     public static class Renderer {
         static Shader shader;
 
         static boolean init() {
-            shader = new Shader("circle");
+            shader = new Shader(GLAdapter.CIRCLE_QUADS ? "circle_quad" : "circle_point");
             return true;
         }
 
@@ -66,12 +93,14 @@ public class CircleBucket extends RenderBucket {
             int uMVP, uColor, uScale, aPos;
 
             Shader(String shaderFile) {
-                gl.enable(GL.VERTEX_PROGRAM_POINT_SIZE);
+                if (!GLAdapter.CIRCLE_QUADS)
+                    gl.enable(GL.VERTEX_PROGRAM_POINT_SIZE);
 
-                // OpenGL needs GLSL version 120
                 String version = null;
-                if (GLAdapter.GDX_DESKTOP_QUIRKS)
+                if (!GLAdapter.CIRCLE_QUADS && GLAdapter.GDX_DESKTOP_QUIRKS) {
+                    // OpenGL requires GLSL version 120 for gl_PointCoord
                     version = "120";
+                }
 
                 if (!createVersioned(shaderFile, version))
                     return;
@@ -106,10 +135,16 @@ public class CircleBucket extends RenderBucket {
                 gl.vertexAttribPointer(s.aPos, 2, GL.SHORT,
                         false, 0, cb.vertexOffset);
 
-                gl.drawElements(GL.POINTS,
+                if (GLAdapter.CIRCLE_QUADS)
-                        cb.numIndices,
+                    gl.drawElements(GL.TRIANGLES,
-                        GL.UNSIGNED_SHORT,
+                            cb.numIndices,
-                        cb.indiceOffset);
+                            GL.UNSIGNED_SHORT,
+                            cb.indiceOffset);
+                else
+                    gl.drawElements(GL.POINTS,
+                            cb.numIndices,
+                            GL.UNSIGNED_SHORT,
+                            cb.indiceOffset);
             }
 
             return b;