Removed submodule maplibre-gl-js (#938)

shaders/hillshade_prepare.vertex.glsl

@@ -0,0 +1,15 @@
+uniform mat4 u_matrix;
+uniform vec2 u_dimension;
+
+attribute vec2 a_pos;
+attribute vec2 a_texture_pos;
+
+varying vec2 v_pos;
+
+void main() {
+    gl_Position = u_matrix * vec4(a_pos, 0, 1);
+
+    highp vec2 epsilon = 1.0 / u_dimension;
+    float scale = (u_dimension.x - 2.0) / u_dimension.x;
+    v_pos = (a_texture_pos / 8192.0) * scale + epsilon;
+}