Migrate rendering to OpenGL 3.2 / OpenGL ES 3.0.

OpenRA.Game/Settings.cs

@@ -160,6 +160,9 @@ namespace OpenRA
 		[Desc("Disable separate OpenGL render thread on Windows operating systems.")]
 		public bool DisableWindowsRenderThread = true;
 
+		[Desc("Use OpenGL ES if both ES and regular OpenGL are available.")]
+		public bool PreferGLES = false;
+
 		public int BatchSize = 8192;
 		public int SheetSize = 2048;
 

OpenRA.Platforms.Default/FrameBuffer.cs

@@ -33,31 +33,32 @@ namespace OpenRA.Platforms.Default
 
 			OpenGL.glGenFramebuffers(1, out framebuffer);
 			OpenGL.CheckGLError();
-			OpenGL.glBindFramebuffer(OpenGL.FRAMEBUFFER_EXT, framebuffer);
+			OpenGL.glBindFramebuffer(OpenGL.GL_FRAMEBUFFER, framebuffer);
 			OpenGL.CheckGLError();
 
 			// Color
 			this.texture = texture;
 			texture.SetEmpty(size.Width, size.Height);
-			OpenGL.glFramebufferTexture2D(OpenGL.FRAMEBUFFER_EXT, OpenGL.COLOR_ATTACHMENT0_EXT, OpenGL.GL_TEXTURE_2D, texture.ID, 0);
+			OpenGL.glFramebufferTexture2D(OpenGL.GL_FRAMEBUFFER, OpenGL.GL_COLOR_ATTACHMENT0, OpenGL.GL_TEXTURE_2D, texture.ID, 0);
 			OpenGL.CheckGLError();
 
 			// Depth
 			OpenGL.glGenRenderbuffers(1, out depth);
 			OpenGL.CheckGLError();
 
-			OpenGL.glBindRenderbuffer(OpenGL.RENDERBUFFER_EXT, depth);
+			OpenGL.glBindRenderbuffer(OpenGL.GL_RENDERBUFFER, depth);
 			OpenGL.CheckGLError();
 
-			OpenGL.glRenderbufferStorage(OpenGL.RENDERBUFFER_EXT, OpenGL.GL_DEPTH_COMPONENT, size.Width, size.Height);
+			var glDepth = OpenGL.Features.HasFlag(OpenGL.GLFeatures.GLES) ? OpenGL.GL_DEPTH_COMPONENT16 : OpenGL.GL_DEPTH_COMPONENT;
+			OpenGL.glRenderbufferStorage(OpenGL.GL_RENDERBUFFER, glDepth, size.Width, size.Height);
 			OpenGL.CheckGLError();
 
-			OpenGL.glFramebufferRenderbuffer(OpenGL.FRAMEBUFFER_EXT, OpenGL.DEPTH_ATTACHMENT_EXT, OpenGL.RENDERBUFFER_EXT, depth);
+			OpenGL.glFramebufferRenderbuffer(OpenGL.GL_FRAMEBUFFER, OpenGL.GL_DEPTH_ATTACHMENT, OpenGL.GL_RENDERBUFFER, depth);
 			OpenGL.CheckGLError();
 
 			// Test for completeness
-			var status = OpenGL.glCheckFramebufferStatus(OpenGL.FRAMEBUFFER_EXT);
+			var status = OpenGL.glCheckFramebufferStatus(OpenGL.GL_FRAMEBUFFER);
-			if (status != OpenGL.FRAMEBUFFER_COMPLETE_EXT)
+			if (status != OpenGL.GL_FRAMEBUFFER_COMPLETE)
 			{
 				var error = "Error creating framebuffer: {0}\n{1}".F(status, new StackTrace());
 				OpenGL.WriteGraphicsLog(error);
@@ -65,19 +66,14 @@ namespace OpenRA.Platforms.Default
 			}
 
 			// Restore default buffer
-			OpenGL.glBindFramebuffer(OpenGL.FRAMEBUFFER_EXT, 0);
+			OpenGL.glBindFramebuffer(OpenGL.GL_FRAMEBUFFER, 0);
 			OpenGL.CheckGLError();
 		}
 
 		static int[] ViewportRectangle()
 		{
 			var v = new int[4];
-			unsafe
+			OpenGL.glGetIntegerv(OpenGL.GL_VIEWPORT, out v[0]);
-			{
-				fixed (int* ptr = &v[0])
-					OpenGL.glGetIntegerv(OpenGL.GL_VIEWPORT, ptr);
-			}
-
 			OpenGL.CheckGLError();
 			return v;
 		}
@@ -92,7 +88,7 @@ namespace OpenRA.Platforms.Default
 
 			OpenGL.glFlush();
 			OpenGL.CheckGLError();
-			OpenGL.glBindFramebuffer(OpenGL.FRAMEBUFFER_EXT, framebuffer);
+			OpenGL.glBindFramebuffer(OpenGL.GL_FRAMEBUFFER, framebuffer);
 			OpenGL.CheckGLError();
 			OpenGL.glViewport(0, 0, size.Width, size.Height);
 			OpenGL.CheckGLError();
@@ -107,7 +103,7 @@ namespace OpenRA.Platforms.Default
 			VerifyThreadAffinity();
 			OpenGL.glFlush();
 			OpenGL.CheckGLError();
-			OpenGL.glBindFramebuffer(OpenGL.FRAMEBUFFER_EXT, 0);
+			OpenGL.glBindFramebuffer(OpenGL.GL_FRAMEBUFFER, 0);
 			OpenGL.CheckGLError();
 			OpenGL.glViewport(cv[0], cv[1], cv[2], cv[3]);
 			OpenGL.CheckGLError();

OpenRA.Platforms.Default/OpenGL.cs

@@ -24,11 +24,12 @@ namespace OpenRA.Platforms.Default
 		Justification = "C-style naming is kept for consistency with the underlying native API.")]
 	internal static class OpenGL
 	{
+		[Flags]
 		public enum GLFeatures
 		{
 			None = 0,
-			GL2OrGreater = 1,
+			Core = 1,
-			FramebufferExt = 4,
+			GLES = 2,
 		}
 
 		public static GLFeatures Features { get; private set; }
@@ -105,6 +106,7 @@ namespace OpenRA.Platforms.Default
 		public const int GL_DYNAMIC_DRAW = 0x88E8;
 
 		public const int GL_TEXTURE0 = 0x84C0;
+		public const int GL_DEPTH_COMPONENT16 = 0x81A5;
 
 		// OpenGL 2
 		public const int GL_FRAGMENT_SHADER = 0x8B30;
@@ -127,14 +129,17 @@ namespace OpenRA.Platforms.Default
 		public const int GL_RENDERER = 0x1F01;
 		public const int GL_VERSION = 0x1F02;
 		public const int GL_EXTENSIONS = 0x1F03;
+		public const int GL_NUM_EXTENSIONS = 0x821D;
+
 		public const int GL_SHADING_LANGUAGE_VERSION = 0x8B8C;
 
 		// Framebuffers
-		public const int FRAMEBUFFER_EXT = 0x8D40;
+		public const int GL_FRAMEBUFFER = 0x8D40;
-		public const int RENDERBUFFER_EXT = 0x8D41;
+		public const int GL_RENDERBUFFER = 0x8D41;
-		public const int COLOR_ATTACHMENT0_EXT = 0x8CE0;
+		public const int GL_COLOR_ATTACHMENT0 = 0x8CE0;
-		public const int DEPTH_ATTACHMENT_EXT = 0x8D00;
+		public const int GL_DEPTH_ATTACHMENT = 0x8D00;
-		public const int FRAMEBUFFER_COMPLETE_EXT = 0x8CD5;
+		public const int GL_FRAMEBUFFER_COMPLETE = 0x8CD5;
+		public const int GL_FRAMEBUFFER_BINDING = 0x8CA6;
 
 		public delegate void Flush();
 		public static Flush glFlush { get; private set; }
@@ -162,7 +167,18 @@ namespace OpenRA.Platforms.Default
 			}
 		}
 
-		public unsafe delegate int GetIntegerv(int pname, int* param);
+		delegate IntPtr GetStringi(int name, uint index);
+		static GetStringi glGetStringiInternal;
+
+		public static string glGetStringi(int name, uint index)
+		{
+			unsafe
+			{
+				return new string((sbyte*)glGetStringiInternal(name, index));
+			}
+		}
+
+		public unsafe delegate int GetIntegerv(int pname, out int param);
 		public static GetIntegerv glGetIntegerv { get; private set; }
 
 		public delegate void Finish();
@@ -241,6 +257,12 @@ namespace OpenRA.Platforms.Default
 		public delegate void BindBuffer(int target, uint buffer);
 		public static BindBuffer glBindBuffer { get; private set; }
 
+		public delegate void GenVertexArrays(int n, out uint buffers);
+		public static GenVertexArrays glGenVertexArrays { get; private set; }
+
+		public delegate void BindVertexArray(uint buffer);
+		public static BindVertexArray glBindVertexArray { get; private set; }
+
 		public delegate void BufferData(int target, IntPtr size, IntPtr data, int usage);
 		public static BufferData glBufferData { get; private set; }
 
@@ -253,6 +275,9 @@ namespace OpenRA.Platforms.Default
 		public delegate void BindAttribLocation(uint program, int index, string name);
 		public static BindAttribLocation glBindAttribLocation { get; private set; }
 
+		public delegate void BindFragDataLocation(uint program, int colorNumber, string name);
+		public static BindFragDataLocation glBindFragDataLocation { get; private set; }
+
 		public delegate void VertexAttribPointer(int index, int size, int type, bool normalized,
 			int stride, IntPtr pointer);
 		public static VertexAttribPointer glVertexAttribPointer { get; private set; }
@@ -361,6 +386,7 @@ namespace OpenRA.Platforms.Default
 			{
 				glGetError = Bind<GetError>("glGetError");
 				glGetStringInternal = Bind<GetString>("glGetString");
+				glGetStringiInternal = Bind<GetStringi>("glGetStringi");
 			}
 			catch (Exception)
 			{
@@ -368,7 +394,7 @@ namespace OpenRA.Platforms.Default
 			}
 
 			DetectGLFeatures();
-			if (!Features.HasFlag(GLFeatures.GL2OrGreater) || !Features.HasFlag(GLFeatures.FramebufferExt))
+			if (!Features.HasFlag(GLFeatures.Core))
 			{
 				WriteGraphicsLog("Unsupported OpenGL version: " + glGetString(GL_VERSION));
 				throw new InvalidProgramException("OpenGL Version Error: See graphics.log for details.");
@@ -411,7 +437,10 @@ namespace OpenRA.Platforms.Default
 				glBufferData = Bind<BufferData>("glBufferData");
 				glBufferSubData = Bind<BufferSubData>("glBufferSubData");
 				glDeleteBuffers = Bind<DeleteBuffers>("glDeleteBuffers");
+				glGenVertexArrays = Bind<GenVertexArrays>("glGenVertexArrays");
+				glBindVertexArray = Bind<BindVertexArray>("glBindVertexArray");
 				glBindAttribLocation = Bind<BindAttribLocation>("glBindAttribLocation");
+				glBindFragDataLocation = Bind<BindFragDataLocation>("glBindFragDataLocation");
 				glVertexAttribPointer = Bind<VertexAttribPointer>("glVertexAttribPointer");
 				glEnableVertexAttribArray = Bind<EnableVertexAttribArray>("glEnableVertexAttribArray");
 				glDisableVertexAttribArray = Bind<DisableVertexAttribArray>("glDisableVertexAttribArray");
@@ -433,16 +462,16 @@ namespace OpenRA.Platforms.Default
 				glGetTexImage = Bind<GetTexImage>("glGetTexImage");
 				glTexParameteri = Bind<TexParameteri>("glTexParameteri");
 				glTexParameterf = Bind<TexParameterf>("glTexParameterf");
-				glGenFramebuffers = Bind<GenFramebuffers>("glGenFramebuffersEXT");
+				glGenFramebuffers = Bind<GenFramebuffers>("glGenFramebuffers");
-				glBindFramebuffer = Bind<BindFramebuffer>("glBindFramebufferEXT");
+				glBindFramebuffer = Bind<BindFramebuffer>("glBindFramebuffer");
-				glFramebufferTexture2D = Bind<FramebufferTexture2D>("glFramebufferTexture2DEXT");
+				glFramebufferTexture2D = Bind<FramebufferTexture2D>("glFramebufferTexture2D");
-				glDeleteFramebuffers = Bind<DeleteFramebuffers>("glDeleteFramebuffersEXT");
+				glDeleteFramebuffers = Bind<DeleteFramebuffers>("glDeleteFramebuffers");
-				glGenRenderbuffers = Bind<GenRenderbuffers>("glGenRenderbuffersEXT");
+				glGenRenderbuffers = Bind<GenRenderbuffers>("glGenRenderbuffers");
-				glBindRenderbuffer = Bind<BindRenderbuffer>("glBindRenderbufferEXT");
+				glBindRenderbuffer = Bind<BindRenderbuffer>("glBindRenderbuffer");
-				glRenderbufferStorage = Bind<RenderbufferStorage>("glRenderbufferStorageEXT");
+				glRenderbufferStorage = Bind<RenderbufferStorage>("glRenderbufferStorage");
-				glDeleteRenderbuffers = Bind<DeleteRenderbuffers>("glDeleteRenderbuffersEXT");
+				glDeleteRenderbuffers = Bind<DeleteRenderbuffers>("glDeleteRenderbuffers");
-				glFramebufferRenderbuffer = Bind<FramebufferRenderbuffer>("glFramebufferRenderbufferEXT");
+				glFramebufferRenderbuffer = Bind<FramebufferRenderbuffer>("glFramebufferRenderbuffer");
-				glCheckFramebufferStatus = Bind<CheckFramebufferStatus>("glCheckFramebufferStatusEXT");
+				glCheckFramebufferStatus = Bind<CheckFramebufferStatus>("glCheckFramebufferStatus");
 			}
 			catch (Exception e)
 			{
@@ -461,22 +490,24 @@ namespace OpenRA.Platforms.Default
 			try
 			{
 				Version = glGetString(GL_VERSION);
-				var version = Version.Contains(" ") ? Version.Split(' ')[0].Split('.') : Version.Split('.');
 
 				var major = 0;
-				if (version.Length > 0)
-					int.TryParse(version[0], out major);
-
 				var minor = 0;
-				if (version.Length > 1)
-					int.TryParse(version[1], out minor);
 
-				if (major >= 2 && minor >= 0)
+				// Assume that the first numeric token corresponds to the GL version
-					Features |= GLFeatures.GL2OrGreater;
+				foreach (var t in Version.Split())
+				{
+					var split = t.Split('.');
+					if (split.Length >= 2 && int.TryParse(split[0], out major) && int.TryParse(split[1], out minor))
+						break;
+				}
 
-				var hasFramebufferExt = SDL.SDL_GL_ExtensionSupported("GL_EXT_framebuffer_object") == SDL.SDL_bool.SDL_TRUE;
+				// Core features are defined as the shared feature set of GL 3.2 and (GLES 3 + BGRA extension)
-				if (hasFramebufferExt)
+				var hasBGRA = SDL.SDL_GL_ExtensionSupported("GL_EXT_texture_format_BGRA8888") == SDL.SDL_bool.SDL_TRUE;
-					Features |= GLFeatures.FramebufferExt;
+				if (Version.Contains(" ES") && hasBGRA && major >= 3)
+					Features = GLFeatures.Core | GLFeatures.GLES;
+				else if (major > 3 || (major == 3 && minor >= 2))
+					Features = GLFeatures.Core;
 			}
 			catch (Exception) { }
 		}
@@ -516,7 +547,11 @@ namespace OpenRA.Platforms.Default
 			Log.Write("graphics", "GL Version: {0}", glGetString(GL_VERSION));
 			Log.Write("graphics", "Shader Version: {0}", glGetString(GL_SHADING_LANGUAGE_VERSION));
 			Log.Write("graphics", "Available extensions:");
-			Log.Write("graphics", glGetString(GL_EXTENSIONS));
+
+			int extensionCount;
+			glGetIntegerv(GL_NUM_EXTENSIONS, out extensionCount);
+			for (var i = 0; i < extensionCount; i++)
+				Log.Write("graphics", glGetStringi(GL_EXTENSIONS, (uint)i));
 		}
 	}
 }

OpenRA.Platforms.Default/Sdl2GraphicsContext.cs

@@ -37,6 +37,13 @@ namespace OpenRA.Platforms.Default
 
 			OpenGL.Initialize();
 
+			uint vao;
+			OpenGL.CheckGLError();
+			OpenGL.glGenVertexArrays(1, out vao);
+			OpenGL.CheckGLError();
+			OpenGL.glBindVertexArray(vao);
+			OpenGL.CheckGLError();
+
 			OpenGL.glEnableVertexAttribArray(Shader.VertexPosAttributeIndex);
 			OpenGL.CheckGLError();
 			OpenGL.glEnableVertexAttribArray(Shader.TexCoordAttributeIndex);

OpenRA.Platforms.Default/Sdl2PlatformWindow.cs

@@ -75,8 +75,6 @@ namespace OpenRA.Platforms.Default
 
 		public Sdl2PlatformWindow(Size requestWindowSize, WindowMode windowMode, int batchSize)
 		{
-			Console.WriteLine("Using SDL 2 with OpenGL renderer");
-
 			// Lock the Window/Surface properties until initialization is complete
 			lock (syncObject)
 			{
@@ -93,6 +91,25 @@ namespace OpenRA.Platforms.Default
 				SDL.SDL_GL_SetAttribute(SDL.SDL_GLattr.SDL_GL_BLUE_SIZE, 8);
 				SDL.SDL_GL_SetAttribute(SDL.SDL_GLattr.SDL_GL_ALPHA_SIZE, 0);
 
+				// Decide between OpenGL and OpenGL ES rendering
+				// Test whether we can use the preferred renderer and fall back to the other if that fails
+				// If neither works we will throw a graphics error later when trying to create the real window
+				bool useGLES;
+				if (Game.Settings.Graphics.PreferGLES)
+					useGLES = CanCreateGLWindow(3, 0, SDL.SDL_GLprofile.SDL_GL_CONTEXT_PROFILE_ES);
+				else
+					useGLES = !CanCreateGLWindow(3, 2, SDL.SDL_GLprofile.SDL_GL_CONTEXT_PROFILE_CORE);
+
+				var glMajor = 3;
+				var glMinor = useGLES ? 0 : 2;
+				var glProfile = useGLES ? SDL.SDL_GLprofile.SDL_GL_CONTEXT_PROFILE_ES : SDL.SDL_GLprofile.SDL_GL_CONTEXT_PROFILE_CORE;
+
+				SDL.SDL_GL_SetAttribute(SDL.SDL_GLattr.SDL_GL_CONTEXT_MAJOR_VERSION, glMajor);
+				SDL.SDL_GL_SetAttribute(SDL.SDL_GLattr.SDL_GL_CONTEXT_MINOR_VERSION, glMinor);
+				SDL.SDL_GL_SetAttribute(SDL.SDL_GLattr.SDL_GL_CONTEXT_PROFILE_MASK, (int)glProfile);
+
+				Console.WriteLine("Using SDL 2 with OpenGL{0} renderer", useGLES ? " ES" : "");
+
 				SDL.SDL_DisplayMode display;
 				SDL.SDL_GetCurrentDisplayMode(0, out display);
 
@@ -366,5 +383,33 @@ namespace OpenRA.Platforms.Default
 			VerifyThreadAffinity();
 			return input.SetClipboardText(text);
 		}
+
+		static bool CanCreateGLWindow(int major, int minor, SDL.SDL_GLprofile profile)
+		{
+			// Implementation inspired by TestIndividualGLVersion from Veldrid
+			SDL.SDL_GL_SetAttribute(SDL.SDL_GLattr.SDL_GL_CONTEXT_MAJOR_VERSION, major);
+			SDL.SDL_GL_SetAttribute(SDL.SDL_GLattr.SDL_GL_CONTEXT_MINOR_VERSION, minor);
+			SDL.SDL_GL_SetAttribute(SDL.SDL_GLattr.SDL_GL_CONTEXT_PROFILE_MASK, (int)profile);
+
+			var flags = SDL.SDL_WindowFlags.SDL_WINDOW_HIDDEN | SDL.SDL_WindowFlags.SDL_WINDOW_OPENGL;
+			var window = SDL.SDL_CreateWindow("", 0, 0, 1, 1, flags);
+			if (window == IntPtr.Zero || !string.IsNullOrEmpty(SDL.SDL_GetError()))
+			{
+				SDL.SDL_ClearError();
+				return false;
+			}
+
+			var context = SDL.SDL_GL_CreateContext(window);
+			if (context == IntPtr.Zero || SDL.SDL_GL_MakeCurrent(window, context) < 0)
+			{
+				SDL.SDL_ClearError();
+				SDL.SDL_DestroyWindow(window);
+				return false;
+			}
+
+			SDL.SDL_GL_DeleteContext(context);
+			SDL.SDL_DestroyWindow(window);
+			return true;
+		}
 	}
 }

OpenRA.Platforms.Default/Shader.cs

@@ -33,6 +33,9 @@ namespace OpenRA.Platforms.Default
 			var filename = Path.Combine(Platform.GameDir, "glsl", name + "." + ext);
 			var code = File.ReadAllText(filename);
 
+			var version = OpenGL.Features.HasFlag(OpenGL.GLFeatures.GLES) ? "300 es" : "140";
+			code = code.Replace("{VERSION}", version);
+
 			var shader = OpenGL.glCreateShader(type);
 			OpenGL.CheckGLError();
 			unsafe
@@ -77,6 +80,9 @@ namespace OpenRA.Platforms.Default
 			OpenGL.CheckGLError();
 			OpenGL.glBindAttribLocation(program, TexMetadataAttributeIndex, "aVertexTexMetadata");
 			OpenGL.CheckGLError();
+			OpenGL.glBindFragDataLocation(program, 0, "fragColor");
+			OpenGL.CheckGLError();
+
 			OpenGL.glAttachShader(program, vertexShader);
 			OpenGL.CheckGLError();
 			OpenGL.glAttachShader(program, fragmentShader);
@@ -135,6 +141,7 @@ namespace OpenRA.Platforms.Default
 		{
 			VerifyThreadAffinity();
 			OpenGL.glUseProgram(program);
+			OpenGL.CheckGLError();
 
 			// bind the textures
 			foreach (var kv in textures)

OpenRA.Platforms.Default/Texture.cs

@@ -85,7 +85,8 @@ namespace OpenRA.Platforms.Default
 				{
 					var intPtr = new IntPtr((void*)ptr);
 					PrepareTexture();
-					OpenGL.glTexImage2D(OpenGL.GL_TEXTURE_2D, 0, OpenGL.GL_RGBA8, width, height,
+					var glInternalFormat = OpenGL.Features.HasFlag(OpenGL.GLFeatures.GLES) ? OpenGL.GL_BGRA : OpenGL.GL_RGBA8;
+					OpenGL.glTexImage2D(OpenGL.GL_TEXTURE_2D, 0, glInternalFormat, width, height,
 						0, OpenGL.GL_BGRA, OpenGL.GL_UNSIGNED_BYTE, intPtr);
 					OpenGL.CheckGLError();
 				}
@@ -109,7 +110,8 @@ namespace OpenRA.Platforms.Default
 				{
 					var intPtr = new IntPtr((void*)ptr);
 					PrepareTexture();
-					OpenGL.glTexImage2D(OpenGL.GL_TEXTURE_2D, 0, OpenGL.GL_RGBA8, width, height,
+					var glInternalFormat = OpenGL.Features.HasFlag(OpenGL.GLFeatures.GLES) ? OpenGL.GL_BGRA : OpenGL.GL_RGBA8;
+					OpenGL.glTexImage2D(OpenGL.GL_TEXTURE_2D, 0, glInternalFormat, width, height,
 						0, OpenGL.GL_BGRA, OpenGL.GL_UNSIGNED_BYTE, intPtr);
 					OpenGL.CheckGLError();
 				}
@@ -121,7 +123,37 @@ namespace OpenRA.Platforms.Default
 			VerifyThreadAffinity();
 			var data = new byte[4 * Size.Width * Size.Height];
 
+			// GLES doesn't support glGetTexImage so data must be read back via a frame buffer
+			if (OpenGL.Features.HasFlag(OpenGL.GLFeatures.GLES))
+			{
+				// Query the active framebuffer so we can restore it afterwards
+				int lastFramebuffer;
+				OpenGL.glGetIntegerv(OpenGL.GL_FRAMEBUFFER_BINDING, out lastFramebuffer);
+
+				uint framebuffer;
+				OpenGL.glGenFramebuffers(1, out framebuffer);
+				OpenGL.glBindFramebuffer(OpenGL.GL_FRAMEBUFFER, framebuffer);
 				OpenGL.CheckGLError();
+
+				OpenGL.glFramebufferTexture2D(OpenGL.GL_FRAMEBUFFER, OpenGL.GL_COLOR_ATTACHMENT0, OpenGL.GL_TEXTURE_2D, texture, 0);
+				OpenGL.CheckGLError();
+
+				unsafe
+				{
+					fixed (byte* ptr = &data[0])
+					{
+						var intPtr = new IntPtr((void*)ptr);
+						OpenGL.glReadPixels(0, 0, Size.Width, Size.Height, OpenGL.GL_BGRA, OpenGL.GL_UNSIGNED_BYTE, intPtr);
+						OpenGL.CheckGLError();
+					}
+				}
+
+				OpenGL.glBindFramebuffer(OpenGL.GL_FRAMEBUFFER, (uint)lastFramebuffer);
+				OpenGL.glDeleteFramebuffers(1, ref framebuffer);
+				OpenGL.CheckGLError();
+			}
+			else
+			{
 				OpenGL.glBindTexture(OpenGL.GL_TEXTURE_2D, texture);
 				unsafe
 				{
@@ -134,6 +166,8 @@ namespace OpenRA.Platforms.Default
 				}
 
 				OpenGL.CheckGLError();
+			}
+
 			return data;
 		}
 
@@ -145,7 +179,8 @@ namespace OpenRA.Platforms.Default
 
 			Size = new Size(width, height);
 			PrepareTexture();
-			OpenGL.glTexImage2D(OpenGL.GL_TEXTURE_2D, 0, OpenGL.GL_RGBA8, width, height,
+			var glInternalFormat = OpenGL.Features.HasFlag(OpenGL.GLFeatures.GLES) ? OpenGL.GL_BGRA : OpenGL.GL_RGBA8;
+			OpenGL.glTexImage2D(OpenGL.GL_TEXTURE_2D, 0, glInternalFormat, width, height,
 				0, OpenGL.GL_BGRA, OpenGL.GL_UNSIGNED_BYTE, IntPtr.Zero);
 			OpenGL.CheckGLError();
 		}

glsl/combined.frag

@@ -1,3 +1,10 @@
+#version {VERSION}
+#ifdef GL_ES
+precision mediump float;
+#endif
+
+in vec4 vColor;
+
 uniform sampler2D Texture0;
 uniform sampler2D Texture1;
 uniform sampler2D Texture2;
@@ -10,15 +17,17 @@ uniform sampler2D Palette;
 uniform bool EnableDepthPreview;
 uniform float DepthTextureScale;
 
-varying vec4 vTexCoord;
+in vec4 vTexCoord;
-varying vec2 vTexMetadata;
+in vec2 vTexMetadata;
-varying vec4 vChannelMask;
+in vec4 vChannelMask;
-varying vec4 vDepthMask;
+in vec4 vDepthMask;
-varying vec2 vTexSampler;
+in vec2 vTexSampler;
 
-varying vec4 vColorFraction;
+in vec4 vColorFraction;
-varying vec4 vRGBAFraction;
+in vec4 vRGBAFraction;
-varying vec4 vPalettedFraction;
+in vec4 vPalettedFraction;
+
+out vec4 fragColor;
 
 float jet_r(float x)
 {
@@ -38,26 +47,26 @@ float jet_b(float x)
 vec4 Sample(float samplerIndex, vec2 pos)
 {
 	if (samplerIndex < 0.5)
-		return texture2D(Texture0, pos);
+		return texture(Texture0, pos);
 	else if (samplerIndex < 1.5)
-		return texture2D(Texture1, pos);
+		return texture(Texture1, pos);
 	else if (samplerIndex < 2.5)
-		return texture2D(Texture2, pos);
+		return texture(Texture2, pos);
 	else if (samplerIndex < 3.5)
-		return texture2D(Texture3, pos);
+		return texture(Texture3, pos);
 	else if (samplerIndex < 4.5)
-		return texture2D(Texture4, pos);
+		return texture(Texture4, pos);
 	else if (samplerIndex < 5.5)
-		return texture2D(Texture5, pos);
+		return texture(Texture5, pos);
 
-	return texture2D(Texture6, pos);
+	return texture(Texture6, pos);
 }
 
 void main()
 {
 	vec4 x = Sample(vTexSampler.s, vTexCoord.st);
 	vec2 p = vec2(dot(x, vChannelMask), vTexMetadata.s);
-	vec4 c = vPalettedFraction * texture2D(Palette, p) + vRGBAFraction * x + vColorFraction * vTexCoord;
+	vec4 c = vPalettedFraction * texture(Palette, p) + vRGBAFraction * x + vColorFraction * vTexCoord;
 
 	// Discard any transparent fragments (both color and depth)
 	if (c.a == 0.0)
@@ -79,8 +88,8 @@ void main()
 		float r = clamp(jet_r(x), 0.0, 1.0);
 		float g = clamp(jet_g(x), 0.0, 1.0);
 		float b = clamp(jet_b(x), 0.0, 1.0);
-		gl_FragColor = vec4(r, g, b, 1.0);
+		fragColor = vec4(r, g, b, 1.0);
 	}
 	else
-		gl_FragColor = c;
+		fragColor = c;
 }

glsl/combined.vert

@@ -1,19 +1,21 @@
+#version {VERSION}
+
 uniform vec3 Scroll;
 uniform vec3 r1, r2;
 
-attribute vec4 aVertexPosition;
+in vec4 aVertexPosition;
-attribute vec4 aVertexTexCoord;
+in vec4 aVertexTexCoord;
-attribute vec2 aVertexTexMetadata;
+in vec2 aVertexTexMetadata;
 
-varying vec4 vTexCoord;
+out vec4 vTexCoord;
-varying vec2 vTexMetadata;
+out vec2 vTexMetadata;
-varying vec4 vChannelMask;
+out vec4 vChannelMask;
-varying vec4 vDepthMask;
+out vec4 vDepthMask;
-varying vec2 vTexSampler;
+out vec2 vTexSampler;
 
-varying vec4 vColorFraction;
+out vec4 vColorFraction;
-varying vec4 vRGBAFraction;
+out vec4 vRGBAFraction;
-varying vec4 vPalettedFraction;
+out vec4 vPalettedFraction;
 
 vec4 UnpackChannelAttributes(float x)
 {

glsl/model.frag

@@ -1,22 +1,28 @@
+#version {VERSION}
+#ifdef GL_ES
+precision mediump float;
+#endif
+
 uniform sampler2D Palette, DiffuseTexture;
 uniform vec2 PaletteRows;
 
 uniform vec4 LightDirection;
 uniform vec3 AmbientLight, DiffuseLight;
 
-varying vec4 vTexCoord;
+in vec4 vTexCoord;
-varying vec4 vChannelMask;
+in vec4 vChannelMask;
-varying vec4 vNormalsMask;
+in vec4 vNormalsMask;
+out vec4 fragColor;
 
 void main()
 {
-	vec4 x = texture2D(DiffuseTexture, vTexCoord.st);
+	vec4 x = texture(DiffuseTexture, vTexCoord.st);
-	vec4 color = texture2D(Palette, vec2(dot(x, vChannelMask), PaletteRows.x));
+	vec4 color = texture(Palette, vec2(dot(x, vChannelMask), PaletteRows.x));
 	if (color.a < 0.01)
 		discard;
 
-	vec4 y = texture2D(DiffuseTexture, vTexCoord.pq);
+	vec4 y = texture(DiffuseTexture, vTexCoord.pq);
-	vec4 normal = (2.0 * texture2D(Palette, vec2(dot(y, vNormalsMask), PaletteRows.y)) - 1.0);
+	vec4 normal = (2.0 * texture(Palette, vec2(dot(y, vNormalsMask), PaletteRows.y)) - 1.0);
 	vec3 intensity = AmbientLight + DiffuseLight * max(dot(normal, LightDirection), 0.0);
-	gl_FragColor = vec4(intensity * color.rgb, color.a);
+	fragColor = vec4(intensity * color.rgb, color.a);
 }

glsl/model.vert

@@ -1,12 +1,14 @@
+#version {VERSION}
+
 uniform mat4 View;
 uniform mat4 TransformMatrix;
 
-attribute vec4 aVertexPosition;
+in vec4 aVertexPosition;
-attribute vec4 aVertexTexCoord;
+in vec4 aVertexTexCoord;
-attribute vec2 aVertexTexMetadata;
+in vec2 aVertexTexMetadata;
-varying vec4 vTexCoord;
+out vec4 vTexCoord;
-varying vec4 vChannelMask;
+out vec4 vChannelMask;
-varying vec4 vNormalsMask;
+out vec4 vNormalsMask;
 
 vec4 DecodeMask(float x)
 {