Increased the OpenGL ES constant depth bias adjustment to reduce self-shadowing artifacts. Do not use cascaded shadow mapping on OpenGL ES, so that the low quality shadow mode can avoid dependent texture reads altogether for much higher performance on iOS. Updated documentation of the GetPlatform() function.

Bin/CoreData/Shaders/GLSL/Lighting.glsl

@@ -60,12 +60,8 @@ float GetVertexLightVolumetric(int index, vec3 worldPos)
 
 #ifdef SHADOW
 
-#ifdef DIRLIGHT
-    #ifndef GL_ES
-        #define NUMCASCADES 4
-    #else
-        #define NUMCASCADES 2
-    #endif
+#if defined(DIRLIGHT) && !defined(GL_ES)
+    #define NUMCASCADES 4
 #else
     #define NUMCASCADES 1
 #endif
@@ -126,12 +122,8 @@ float GetIntensity(vec3 color)
 
 #ifdef SHADOW
 
-#ifdef DIRLIGHT
-    #ifndef GL_ES
-        #define NUMCASCADES 4
-    #else
-        #define NUMCASCADES 2
-    #endif
+#if defined(DIRLIGHT) && !defined(GL_ES)
+    #define NUMCASCADES 4
 #else
     #define NUMCASCADES 1
 #endif
@@ -240,14 +232,7 @@ float GetDirShadowDeferred(vec4 projWorldPos, float depth)
 #else
 float GetDirShadow(const vec4 iShadowPos[NUMCASCADES], float depth)
 {
-    vec4 shadowPos;
-
-    if (depth < cShadowSplits.x)
-        shadowPos = iShadowPos[0];
-    else
-        shadowPos = iShadowPos[1];
-
-    return GetDirShadowFade(GetShadow(shadowPos), depth);
+    return GetDirShadowFade(GetShadow(iShadowPos[0]), depth);
 }
 #endif
 #endif

Bin/Data/Scripts/NinjaSnowWar.as

@@ -149,9 +149,13 @@ void InitScene()
 
     gameScene.LoadXML(cache.GetFile("Scenes/NinjaSnowWar.xml"));
 
-    // On mobile devices render the shadowmap first
-    if (GetPlatform() == "Android" || GetPlatform() == "iOS")
+    // On mobile devices render the shadowmap first. Also adjust the shadow quality for performance
+    String platform = GetPlatform();
+    if (platform == "Android" || platform == "iOS" || platform == "Raspberry Pi")
+    {
         renderer.reuseShadowMaps = false;
+        renderer.shadowQuality = SHADOWQUALITY_LOW_16BIT;
+    }
 }
 
 void InitNetworking()

Docs/Reference.dox

@@ -843,7 +843,7 @@ OpenGL ES 2.0 has further limitations:
 
 - To reduce fillrate, the stencil buffer is not reserved and the stencil test is not available. As a consequence, the light stencil masking optimization is not used.
 
-- For improved performance, shadow mapping quality is reduced: there is no smooth PCF filtering and directional lights can have a maximum of 2 cascades.
+- For improved performance, shadow mapping quality is reduced: there is no smooth PCF filtering and directional lights do not support shadow cascades. Consider also using the low shadow quality (1 sample) to avoid dependent texture reads in the pixel shader, which have an especially high performance cost on iOS hardware.
 
 - Custom clip planes are not currently supported.
 

Source/Engine/Core/ProcessUtils.h

@@ -59,7 +59,7 @@ URHO3D_API const Vector<String>& ParseArguments(int argc, char** argv);
 URHO3D_API const Vector<String>& GetArguments();
 /// Read input from the console window. Return empty if no input.
 URHO3D_API String GetConsoleInput();
-/// Return the runtime platform identifier. Currently either "Windows", "Linux", "Mac OS X" or "Android".
+/// Return the runtime platform identifier, one of "Windows", "Linux", "Mac OS X", "Android", "iOS" or "Raspberry Pi".
 URHO3D_API String GetPlatform();
 /// Return the number of physical CPU cores.
 URHO3D_API unsigned GetNumPhysicalCPUs();

Source/Engine/Graphics/Batch.cpp

@@ -254,7 +254,7 @@ void Batch::Prepare(View* view, bool setModelTransform) const
         // On OpenGL ES slope-scaled bias can not be guaranteed to be available, and the shadow filtering is more coarse,
         // so use a higher constant bias
         #ifdef GL_ES_VERSION_2_0
-        constantBias *= 1.5f;
+        constantBias *= 2.0f;
         #endif
         projection.m22_ += projection.m32_ * constantBias;
         projection.m23_ += projection.m33_ * constantBias;

Source/Engine/Graphics/Light.h

@@ -49,7 +49,7 @@ static const int MAX_LIGHT_SPLITS = 6;
 #if !defined(ANDROID) && !defined(IOS) && !defined(RASPI)
 static const int MAX_CASCADE_SPLITS = 4;
 #else
-static const int MAX_CASCADE_SPLITS = 2;
+static const int MAX_CASCADE_SPLITS = 1;
 #endif
 
 /// Shadow depth bias parameters.