Location renderer: allow external shaders, move existing to glsl files, closes #317

vtm/resources/assets/shaders/location_1.glsl

@@ -0,0 +1,44 @@
+#ifdef GLES
+precision mediump float;
+#endif
+uniform mat4 u_mvp;
+uniform float u_phase;
+uniform float u_scale;
+attribute vec2 a_pos;
+varying vec2 v_tex;
+void main() {
+  gl_Position = u_mvp * vec4(a_pos * u_scale * u_phase, 0.0, 1.0);
+  v_tex = a_pos;
+}
+
+$$
+
+#ifdef GLES
+precision mediump float;
+#endif
+varying vec2 v_tex;
+uniform float u_scale;
+uniform float u_phase;
+uniform vec2 u_dir;
+void main() {
+    float len = 1.0 - length(v_tex);
+    if (u_dir.x == 0.0 && u_dir.y == 0.0){
+        gl_FragColor = vec4(0.2, 0.2, 0.8, 1.0) * len;
+    } else {
+        // outer ring
+        float a = smoothstep(0.0, 2.0 / u_scale, len);
+        // inner ring
+        float b = 0.5 * smoothstep(4.0 / u_scale, 5.0 / u_scale, len);
+        // center point
+        float c = 0.5 * (1.0 - smoothstep(14.0 / u_scale, 16.0 / u_scale, 1.0 - len));
+        vec2 dir = normalize(v_tex);
+        float d = 1.0 - dot(dir, u_dir);
+        // 0.5 width of viewshed
+        d = clamp(step(0.5, d), 0.4, 0.7);
+        // - subtract inner from outer to create the outline
+        // - multiply by viewshed
+        // - add center point
+        a = d * (a - (b + c)) + c;
+        gl_FragColor = vec4(0.2, 0.2, 0.8, 1.0) * a;
+    }
+}

vtm/resources/assets/shaders/location_1_reverse.glsl

@@ -0,0 +1,44 @@
+#ifdef GLES
+precision mediump float;
+#endif
+uniform mat4 u_mvp;
+uniform float u_phase;
+uniform float u_scale;
+attribute vec2 a_pos;
+varying vec2 v_tex;
+void main() {
+  gl_Position = u_mvp * vec4(a_pos * u_scale * u_phase, 0.0, 1.0);
+  v_tex = a_pos;
+}
+
+$$
+
+#ifdef GLES
+precision mediump float;
+#endif
+varying vec2 v_tex;
+uniform float u_scale;
+uniform float u_phase;
+uniform vec2 u_dir;
+void main() {
+    float len = 1.0 - length(v_tex);
+    if (u_dir.x == 0.0 && u_dir.y == 0.0){
+        gl_FragColor = vec4(0.2, 0.2, 0.8, 1.0) * len;
+    } else {
+        // outer ring
+        float a = smoothstep(0.0, 2.0 / u_scale, len);
+        // inner ring
+        float b = 0.5 * smoothstep(4.0 / u_scale, 5.0 / u_scale, len);
+        // center point
+        float c = 0.5 * (1.0 - smoothstep(14.0 / u_scale, 16.0 / u_scale, 1.0 - len));
+        vec2 dir = normalize(v_tex);
+        float d = dot(dir, u_dir);
+        // 0.5 width of viewshed
+        d = clamp(step(0.5, d), 0.4, 0.7);
+        // - subtract inner from outer to create the outline
+        // - multiply by viewshed
+        // - add center point
+        a = d * (a - (b + c)) + c;
+        gl_FragColor = vec4(0.2, 0.2, 0.8, 1.0) * a;
+    }
+}

vtm/resources/assets/shaders/location_2.glsl

@@ -0,0 +1,40 @@
+#ifdef GLES
+precision mediump float;
+#endif
+uniform mat4 u_mvp;
+uniform float u_phase;
+uniform float u_scale;
+attribute vec2 a_pos;
+varying vec2 v_tex;
+void main() {
+  gl_Position = u_mvp * vec4(a_pos * u_scale * u_phase, 0.0, 1.0);
+  v_tex = a_pos;
+}
+
+$$
+
+#ifdef GLES
+precision mediump float;
+#endif
+varying vec2 v_tex;
+uniform float u_scale;
+uniform float u_phase;
+uniform vec2 u_dir;
+void main() {
+    float len = 1.0 - length(v_tex);
+    // outer ring
+    float a = smoothstep(0.0, 2.0 / u_scale, len);
+    // inner ring
+    float b = 0.8 * smoothstep(3.0 / u_scale, 4.0 / u_scale, len);
+    // center point
+    float c = 0.5 * (1.0 - smoothstep(14.0 / u_scale, 16.0 / u_scale, 1.0 - len));
+    vec2 dir = normalize(v_tex);
+    float d = dot(dir, u_dir);
+    // 0.5 width of viewshed
+    d = clamp(smoothstep(0.7, 0.7 + 2.0/u_scale, d) * len, 0.0, 1.0);
+    // - subtract inner from outer to create the outline
+    // - multiply by viewshed
+    // - add center point
+    a = max(d, (a - (b + c)) + c);
+    gl_FragColor = vec4(0.2, 0.2, 0.8, 1.0) * a;
+}