depth-development-support.patch

depth-development-support.patch

diff --git a/src/render/painter.js b/src/render/painter.js
index 55fabcf62..4cb3fdeb1 100644
--- a/src/render/painter.js
+++ b/src/render/painter.js
@@ -645,7 +645,7 @@ class Painter {
         const key = `${name}${programConfiguration ? programConfiguration.cacheKey : ''}${this._showOverdrawInspector ? '/overdraw' : ''}
             ${terrain ? '/terrain' : ''}${rtt ? '/rtt' : ''}`;
         if (!this.cache[key]) {
-            this.cache[key] = new Program(this.context, shaders[name], programConfiguration, programUniforms[name], this._showOverdrawInspector, terrain, rtt);
+            this.cache[key] = new Program(this.context, shaders[name], programConfiguration, programUniforms[name], this._showOverdrawInspector, terrain, rtt, name === 'terrainRaster');
         }
         return this.cache[key];
     }
diff --git a/src/render/program.js b/src/render/program.js
index fce581ee0..81eb4f319 100644
--- a/src/render/program.js
+++ b/src/render/program.js
@@ -38,7 +38,8 @@ class Program<Us: UniformBindings> {
                 fixedUniforms: (Context, UniformLocations) => Us,
                 showOverdrawInspector: boolean,
                 terrain: ?boolean,
-                renderingToTexture: ?boolean) {
+                renderingToTexture: ?boolean,
+                debugDepth: ?boolean) {
         const gl = context.gl;
         this.program = gl.createProgram();
 
@@ -52,6 +53,9 @@ class Program<Us: UniformBindings> {
         if (renderingToTexture) {
             defines.push('#define RENDER_TO_TEXTURE;');
         }
+        if (debugDepth) {
+            defines.push('#define DEBUG_DEPTH;');
+        }
 
         const fragmentSource = defines.concat(prelude.fragmentSource, source.fragmentSource).join('\n');
         const vertexSource = defines.concat(prelude.vertexSource, preludeTerrain.vertexSource, source.vertexSource).join('\n');
diff --git a/src/shaders/terrain_raster.fragment.glsl b/src/shaders/terrain_raster.fragment.glsl
index 10029f61c..594bf0e0b 100644
--- a/src/shaders/terrain_raster.fragment.glsl
+++ b/src/shaders/terrain_raster.fragment.glsl
@@ -1,9 +1,16 @@
 uniform sampler2D u_image0;
 varying vec2 v_pos0;
 
+#ifdef DEBUG_DEPTH
+varying vec4 v_color;
+#endif
+
 void main() {
     gl_FragColor = texture2D(u_image0, v_pos0);
 #ifdef OVERDRAW_INSPECTOR
     gl_FragColor = vec4(1.0);
 #endif
+#ifdef DEBUG_DEPTH
+    gl_FragColor = v_color;
+#endif
 }
diff --git a/src/shaders/terrain_raster.vertex.glsl b/src/shaders/terrain_raster.vertex.glsl
index 9ea9396c2..b5eb0e264 100644
--- a/src/shaders/terrain_raster.vertex.glsl
+++ b/src/shaders/terrain_raster.vertex.glsl
@@ -8,10 +8,26 @@ varying vec2 v_pos0;
 
 const float skirtOffset = 24575.0;
 
+varying float v_depth;
+
+#ifdef DEBUG_DEPTH
+varying vec4 v_color;
+#endif
+
 void main() {
     v_pos0 = a_texture_pos / 8192.0;
     float skirt = float(a_pos.x >= skirtOffset);
     float elevation = elevation(a_texture_pos) - skirt * u_skirt_height;
     vec2 decodedPos = a_pos - vec2(skirt * skirtOffset, 0.0);
     gl_Position = u_matrix * vec4(decodedPos, elevation, 1.0);
+    v_depth = gl_Position.z / gl_Position.w;
+
+#ifdef DEBUG_DEPTH
+    vec3 coord = gl_Position.xyz / gl_Position.w;
+    if (!isOccluded(gl_Position)) {
+        v_color = texture2D(u_depth, (coord.xy + 1.0) * 0.5);
+    } else {
+        v_color = vec4(0.0);
+    }
+#endif
 }
diff --git a/src/terrain/draw_terrain_raster.js b/src/terrain/draw_terrain_raster.js
index 23be49365..c164e3900 100644
--- a/src/terrain/draw_terrain_raster.js
+++ b/src/terrain/draw_terrain_raster.js
@@ -46,7 +46,7 @@ function drawTerrainRaster(painter: Painter, terrain: Terrain, sourceCache: Sour
         tile.texture.bind(gl.LINEAR, gl.CLAMP_TO_EDGE, gl.LINEAR_MIPMAP_NEAREST);
 
         const uniformValues = terrainRasterUniformValues(coord.posMatrix, painter.transform.zoom);
-        terrain.setupElevationDraw(tile, program);
+        terrain.setupElevationDraw(tile, program, true);
 
         program.draw(context, gl.TRIANGLES, depthMode, stencilMode, colorMode, CullFaceMode.backCCW,
             uniformValues, "terrain_raster", terrain.gridBuffer, terrain.gridIndexBuffer, terrain.gridSegments);
diff --git a/src/ui/map.js b/src/ui/map.js
index c05c5f48e..053140eba 100755
--- a/src/ui/map.js
+++ b/src/ui/map.js
@@ -109,7 +109,7 @@ const defaultMaxZoom = 22;
 
 // the default values, but also the valid range
 const defaultMinPitch = 0;
-const defaultMaxPitch = 60;
+const defaultMaxPitch = 83;
 
 const defaultOptions = {
     center: [0, 0],