OPENGL: Add a Context class used to describe the active OpenGL context

backends/graphics/surfacesdl/surfacesdl-graphics.cpp

@@ -45,7 +45,7 @@
 #include "gui/EventRecorder.h"
 
 #ifdef USE_OPENGL
-#include "graphics/opengl/extensions.h"
+#include "graphics/opengl/context.h"
 #endif
 
 static const OSystem::GraphicsMode s_supportedGraphicsModes[] = {
@@ -234,8 +234,8 @@ Graphics::PixelBuffer SurfaceSdlGraphicsManager::setupScreen(uint screenW, uint
 			SDL_putenv(const_cast<char *>("SDL_VIDEO_WINDOW_POS=9000,9000"));
 			SDL_SetVideoMode(32, 32, 0, SDL_OPENGL);
 			SDL_putenv(const_cast<char *>("SDL_VIDEO_WINDOW_POS=centered"));
-			OpenGL::initExtensions();
+			OpenGLContext.initialize(OpenGL::kContextGL);
-			framebufferSupported = OpenGL::isExtensionSupported("GL_EXT_framebuffer_object");
+			framebufferSupported = OpenGLContext.framebufferObjectSupported;
 			if (_fullscreen && framebufferSupported) {
 				screenW = _desktopW;
 				screenH = _desktopH;
@@ -395,7 +395,7 @@ Graphics::PixelBuffer SurfaceSdlGraphicsManager::setupScreen(uint screenW, uint
 		_boxShader->enableVertexAttribute("texcoord", _boxVerticesVBO, 2, GL_FLOAT, GL_TRUE, 2 * sizeof(float), 0);
 #endif
 
-		OpenGL::initExtensions();
+		OpenGLContext.initialize(OpenGL::kContextGL);
 
 	}
 #endif
@@ -1062,6 +1062,8 @@ void SurfaceSdlGraphicsManager::closeOverlay() {
 			SDL_FreeSurface(_subScreen);
 			_subScreen = nullptr;
 		}
+
+		OpenGL::Context::destroy();
 #endif
 	}
 }

backends/platform/android/gfx.cpp

@@ -43,7 +43,7 @@
 #include "common/tokenizer.h"
 #include "graphics/conversion.h"
 #include "graphics/opengl/shader.h"
-#include "graphics/opengl/extensions.h"
+#include "graphics/opengl/context.h"
 
 #include "backends/platform/android/android.h"
 #include "backends/platform/android/jni.h"
@@ -216,7 +216,7 @@ void OSystem_Android::initSurface() {
 	JNI::initSurface();
 
 	// Initialize OpenGLES context.
-	OpenGL::initExtensions();
+	OpenGLContext.initialize(OpenGL::kContextGLES2);
 	logExtensions();
 	GLESTexture::initGL();
 
@@ -252,6 +252,8 @@ void OSystem_Android::deinitSurface() {
 	if (_mouse_texture)
 		_mouse_texture->release();
 
+	OpenGL::Context::destroy();
+
 	JNI::deinitSurface();
 }
 

backends/platform/android/texture.cpp

@@ -42,7 +42,7 @@
 #include "base/main.h"
 #include "graphics/surface.h"
 #include "graphics/opengl/shader.h"
-#include "graphics/opengl/extensions.h"
+#include "graphics/opengl/context.h"
 
 #include "common/rect.h"
 #include "common/array.h"
@@ -83,7 +83,7 @@ const GLfloat vertices[] = {
 };
 
 void GLESBaseTexture::initGL() {
-	npot_supported = OpenGL::isExtensionSupported("GL_ARB_texture_non_power_of_two");
+	npot_supported = OpenGLContext.NPOTSupported;
 
 	const char* attributes[] = { "position", "texcoord", NULL };
 	g_box_shader = OpenGL::Shader::fromStrings("control", OpenGL::BuiltinShaders::controlVertex, OpenGL::BuiltinShaders::controlFragment, attributes);

engines/myst3/gfx_opengl.cpp

@@ -33,6 +33,7 @@
 #if defined(USE_OPENGL) && !defined(USE_GLES2)
 
 #include "graphics/colormasks.h"
+#include "graphics/opengl/context.h"
 #include "graphics/pixelbuffer.h"
 #include "graphics/surface.h"
 
@@ -47,15 +48,14 @@ Renderer *CreateGfxOpenGL(OSystem *system) {
 }
 
 OpenGLRenderer::OpenGLRenderer(OSystem *system) :
-		BaseRenderer(system),
+		BaseRenderer(system) {
-		_nonPowerOfTwoTexSupport(false) {
 }
 
 OpenGLRenderer::~OpenGLRenderer() {
 }
 
 Texture *OpenGLRenderer::createTexture(const Graphics::Surface *surface) {
-	return new OpenGLTexture(surface, _nonPowerOfTwoTexSupport);
+	return new OpenGLTexture(surface);
 }
 
 void OpenGLRenderer::freeTexture(Texture *texture) {
@@ -71,11 +71,9 @@ void OpenGLRenderer::init() {
 	computeScreenViewport();
 
 	// Check the available OpenGL extensions
-	const char* extensions = (const char*)glGetString(GL_EXTENSIONS);
+	if (!OpenGLContext.NPOTSupported) {
-	if (strstr(extensions, "GL_ARB_texture_non_power_of_two"))
-		_nonPowerOfTwoTexSupport = true;
-	else
 		warning("GL_ARB_texture_non_power_of_two is not available.");
+	}
 
 	glMatrixMode(GL_PROJECTION);
 	glLoadIdentity();

engines/myst3/gfx_opengl.h

@@ -58,10 +58,6 @@ public:
 	virtual Graphics::Surface *getScreenshot() override;
 private:
 	void drawFace(uint face, Texture *texture);
-
-	Math::Matrix4 _mvpMatrix;
-
-	bool _nonPowerOfTwoTexSupport;
 };
 
 } // End of namespace Myst3

engines/myst3/gfx_opengl_shaders.cpp

@@ -57,7 +57,6 @@
 #include "math/rect2d.h"
 #include "math/quat.h"
 
-#include "graphics/opengl/extensions.h"
 #include "graphics/opengl/shader.h"
 
 #include "engines/myst3/gfx.h"
@@ -126,13 +125,7 @@ ShaderRenderer::~ShaderRenderer() {
 }
 
 Texture *ShaderRenderer::createTexture(const Graphics::Surface *surface) {
-	OpenGLTexture *texture = new OpenGLTexture(surface, true);
+	return new OpenGLTexture(surface);
-
-#if defined(USE_GLES2)
-	texture->setUnpackSubImageSupport(OpenGL::isExtensionSupported("GL_EXT_unpack_subimage"));
-#endif
-
-	return texture;
 }
 
 void ShaderRenderer::freeTexture(Texture *texture) {

engines/myst3/gfx_opengl_texture.cpp

@@ -26,10 +26,7 @@
 
 #include "engines/myst3/gfx_opengl_texture.h"
 
-#if !defined(GL_UNPACK_ROW_LENGTH)
+#include "graphics/opengl/context.h"
-// The Android SDK does not declare GL_UNPACK_ROW_LENGTH_EXT
-#define GL_UNPACK_ROW_LENGTH 0x0CF2
-#endif
 
 namespace Myst3 {
 
@@ -45,15 +42,13 @@ static uint32 upperPowerOfTwo(uint32 v) {
 	return v;
 }
 
-OpenGLTexture::OpenGLTexture(const Graphics::Surface *surface, bool nonPoTSupport) :
+OpenGLTexture::OpenGLTexture(const Graphics::Surface *surface) {
-	_unpackSubImageSupport(true) {
-
 	width = surface->w;
 	height = surface->h;
 	format = surface->format;
 
 	// Pad the textures if non power of two support is unavailable
-	if (nonPoTSupport) {
+	if (OpenGLContext.NPOTSupported) {
 		internalHeight = height;
 		internalWidth = width;
 	} else {
@@ -101,7 +96,7 @@ void OpenGLTexture::update(const Graphics::Surface *surface) {
 void OpenGLTexture::updateTexture(const Graphics::Surface* surface, const Common::Rect& rect) {
 	glBindTexture(GL_TEXTURE_2D, id);
 
-	if (_unpackSubImageSupport) {
+	if (OpenGLContext.unpackSubImageSupported) {
 		const Graphics::Surface subArea = surface->getSubArea(rect);
 
 		glPixelStorei(GL_UNPACK_ROW_LENGTH, surface->pitch / surface->format.bytesPerPixel);

engines/myst3/gfx_opengl_texture.h

@@ -33,14 +33,12 @@ namespace Myst3 {
 
 class OpenGLTexture : public Texture {
 public:
-	OpenGLTexture(const Graphics::Surface *surface, bool nonPoTSupport = false);
+	OpenGLTexture(const Graphics::Surface *surface);
 	virtual ~OpenGLTexture();
 
 	void update(const Graphics::Surface *surface) override;
 	void updatePartial(const Graphics::Surface *surface, const Common::Rect &rect) override;
 
-	void setUnpackSubImageSupport(bool unpackSubImageSupport) { _unpackSubImageSupport = unpackSubImageSupport; }
-
 	static void byteswapSurface(Graphics::Surface *surface);
 
 	GLuint id;
@@ -51,8 +49,6 @@ public:
 
 private:
 	void updateTexture(const Graphics::Surface *surface, const Common::Rect &rect);
-
-	bool _unpackSubImageSupport;
 };
 
 } // End of namespace Myst3

engines/stark/gfx/opengls.cpp

@@ -20,7 +20,6 @@
  *
  */
 
-#include <graphics/opengl/extensions.h>
 #include "engines/stark/gfx/opengls.h"
 
 #include "common/config-manager.h"

graphics/module.mk

@@ -27,9 +27,9 @@ MODULE_OBJS := \
 	yuv_to_rgb.o \
 	yuva_to_rgba.o \
 	pixelbuffer.o \
+	opengl/context.o \
 	opengl/framebuffer.o \
 	opengl/texture.o \
-	opengl/extensions.o \
 	opengl/shader.o \
 	opengl/box_shaders.o \
 	opengl/control_shaders.o \

graphics/opengl/context.cpp

@@ -0,0 +1,153 @@
+/* ResidualVM - A 3D game interpreter
+ *
+ * ResidualVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+
+#include "graphics/opengl/context.h"
+
+#include "common/debug.h"
+#include "common/str.h"
+#include "common/textconsole.h"
+#include "common/tokenizer.h"
+
+#include "graphics/opengl/system_headers.h"
+
+#ifdef USE_OPENGL
+
+namespace Common {
+DECLARE_SINGLETON(OpenGL::Context);
+}
+
+namespace OpenGL {
+
+Context::Context() {
+	reset();
+}
+
+void Context::reset() {
+	maxTextureSize = 0;
+
+	NPOTSupported = false;
+	shadersSupported = false;
+	framebufferObjectSupported = false;
+	packedDepthStencilSupported = false;
+	unpackSubImageSupported = false;
+}
+
+void Context::initialize(ContextType contextType) {
+	// Initialize default state.
+	reset();
+
+	type = contextType;
+
+	// Obtain maximum texture size.
+	glGetIntegerv(GL_MAX_TEXTURE_SIZE, &maxTextureSize);
+	debug(5, "OpenGL maximum texture size: %d", maxTextureSize);
+
+	const char *extString = (const char *)glGetString(GL_EXTENSIONS);
+
+	bool ARBShaderObjects = false;
+	bool ARBShadingLanguage100 = false;
+	bool ARBVertexShader = false;
+	bool ARBFragmentShader = false;
+
+	Common::StringTokenizer tokenizer(extString, " ");
+	while (!tokenizer.empty()) {
+		Common::String token = tokenizer.nextToken();
+
+		if (token == "GL_ARB_texture_non_power_of_two" || token == "GL_OES_texture_npot") {
+			NPOTSupported = true;
+		} else if (token == "GL_ARB_shader_objects") {
+			ARBShaderObjects = true;
+		} else if (token == "GL_ARB_shading_language_100") {
+			ARBShadingLanguage100 = true;
+		} else if (token == "GL_ARB_vertex_shader") {
+			ARBVertexShader = true;
+		} else if (token == "GL_ARB_fragment_shader") {
+			ARBFragmentShader = true;
+		} else if (token == "GL_EXT_framebuffer_object") {
+			framebufferObjectSupported = true;
+		} else if (token == "GL_EXT_packed_depth_stencil" || token == "GL_OES_packed_depth_stencil") {
+			packedDepthStencilSupported = true;
+		} else if (token == "GL_EXT_unpack_subimage") {
+			unpackSubImageSupported = true;
+		}
+	}
+
+	int glslVersion = getGLSLVersion();
+	debug(5, "OpenGL GLSL version: %d", glslVersion);
+
+	if (type == kContextGLES2) {
+		// GLES2 always has (limited) NPOT support.
+		NPOTSupported = true;
+
+		// GLES2 always has shader support.
+		shadersSupported = true;
+
+		// GLES2 always has FBO support.
+		framebufferObjectSupported = true;
+	} else {
+		shadersSupported = ARBShaderObjects && ARBShadingLanguage100 && ARBVertexShader && ARBFragmentShader && glslVersion >= 120;
+
+		// Desktop GL always has unpack sub-image support
+		unpackSubImageSupported = true;
+	}
+
+	// Log context type.
+	switch (type) {
+		case kContextGL:
+			debug(5, "OpenGL: GL context initialized");
+			break;
+
+		case kContextGLES2:
+			debug(5, "OpenGL: GLES2 context initialized");
+			break;
+	}
+
+	// Log features supported by GL context.
+	debug(5, "OpenGL: NPOT texture support: %d", NPOTSupported);
+	debug(5, "OpenGL: Shader support: %d", shadersSupported);
+	debug(5, "OpenGL: FBO support: %d", framebufferObjectSupported);
+	debug(5, "OpenGL: Packed depth stencil support: %d", packedDepthStencilSupported);
+	debug(5, "OpenGL: Unpack subimage support: %d", unpackSubImageSupported);
+}
+
+int Context::getGLSLVersion() const {
+	const char *glslVersionString = (const char *)glGetString(GL_SHADING_LANGUAGE_VERSION);
+
+	const char *glslVersionFormat;
+	if (type == kContextGL) {
+		glslVersionFormat = "%d.%d";
+	} else {
+		glslVersionFormat = "OpenGL ES GLSL ES %d.%d";
+	}
+
+	int glslMajorVersion, glslMinorVersion;
+	if (sscanf(glslVersionString, glslVersionFormat, &glslMajorVersion, &glslMinorVersion) != 2) {
+		warning("Could not parse GLSL version '%s'", glslVersionString);
+		return 0;
+	}
+
+	return glslMajorVersion * 100 + glslMinorVersion;
+}
+
+} // End of namespace OpenGL
+
+#endif

graphics/opengl/context.h

@@ -0,0 +1,88 @@
+/* ResidualVM - A 3D game interpreter
+ *
+ * ResidualVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+
+#ifndef GRAPHICS_OPENGL_CONTEXT_H
+#define GRAPHICS_OPENGL_CONTEXT_H
+
+#include "common/singleton.h"
+
+namespace OpenGL {
+
+enum ContextType {
+	kContextGL,
+	kContextGLES2
+};
+
+/**
+ * Description structure of the OpenGL (ES) context.
+ *
+ * This class is based on LordHoto's OpenGL backend for ScummVM
+ */
+class Context : public Common::Singleton<Context> {
+public:
+	Context();
+
+	/**
+	 * Initialize the context description from currently active context.
+	 *
+	 * The extensions and features are marked as available according
+	 * to the current context capabilities.
+	 */
+	void initialize(ContextType contextType);
+
+	/**
+	 * Reset context.
+	 *
+	 * This marks all extensions as unavailable.
+	 */
+	void reset();
+
+	/** The type of the active context. */
+	ContextType type;
+
+	/** The maximum texture size supported by the context. */
+	int maxTextureSize;
+
+	/** Whether GL_ARB_texture_non_power_of_two is available or not. */
+	bool NPOTSupported;
+
+	/** Whether shader support is available or not. */
+	bool shadersSupported;
+
+	/** Whether FBO support is available or not. */
+	bool framebufferObjectSupported;
+
+	/** Whether packing the depth and stencil buffers is possible or not. */
+	bool packedDepthStencilSupported;
+
+	/** Whether specifying a pitch when uploading to textures is available or not */
+	bool unpackSubImageSupported;
+
+	int getGLSLVersion() const;
+};
+
+} // End of namespace OpenGL
+
+/** Shortcut for accessing the active OpenGL context. */
+#define OpenGLContext OpenGL::Context::instance()
+
+#endif

graphics/opengl/extensions.cpp

@@ -1,52 +0,0 @@
-/* ResidualVM - A 3D game interpreter
- *
- * ResidualVM is the legal property of its developers, whose names
- * are too numerous to list here. Please refer to the COPYRIGHT
- * file distributed with this source distribution.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
- *
- */
-
-#include "common/algorithm.h"
-#include "common/list.h"
-#include "common/str.h"
-#include "common/tokenizer.h"
-
-#include "graphics/opengl/system_headers.h"
-
-#ifdef USE_OPENGL
-
-namespace OpenGL {
-
-static Common::List<Common::String> g_extensions;
-
-void initExtensions() {
-	g_extensions.clear();
-
-	const char *exts = reinterpret_cast<const char *>(glGetString(GL_EXTENSIONS));
-	Common::StringTokenizer tokenizer(exts, " ");
-	while (!tokenizer.empty()) {
-		g_extensions.push_back(tokenizer.nextToken());
-	}
-}
-
-bool isExtensionSupported(const char *wanted) {
-	return g_extensions.end() != find(g_extensions.begin(), g_extensions.end(), wanted);
-}
-
-} // End of namespace OpenGL
-
-#endif

graphics/opengl/extensions.h

@@ -1,33 +0,0 @@
-/* ResidualVM - A 3D game interpreter
- *
- * ResidualVM is the legal property of its developers, whose names
- * are too numerous to list here. Please refer to the COPYRIGHT
- * file distributed with this source distribution.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
- *
- */
-
-#ifndef GRAPHICS_EXTENSIONS_H
-#define GRAPHICS_EXTENSIONS_H
-
-namespace OpenGL {
-
-void initExtensions();
-bool isExtensionSupported(const char *extension);
-
-}
-
-#endif

graphics/opengl/framebuffer.cpp

@@ -42,7 +42,7 @@
 #include "backends/platform/sdl/sdl-sys.h"
 #endif // defined(SDL_BACKEND)
 
-#include "graphics/opengl/extensions.h"
+#include "graphics/opengl/context.h"
 
 #ifdef USE_GLES2
 #define GL_DEPTH24_STENCIL8 GL_DEPTH24_STENCIL8_OES
@@ -101,19 +101,13 @@ static void grabFramebufferObjectPointers() {
 
 
 static bool usePackedBuffer() {
-#ifdef USE_GLES2
+	return OpenGLContext.packedDepthStencilSupported;
-	return isExtensionSupported("GL_OES_packed_depth_stencil");
-#endif
-#ifndef USE_OPENGL_SHADERS
-	return isExtensionSupported("GL_EXT_packed_depth_stencil");
-#endif
-	return true;
 }
 
 FrameBuffer::FrameBuffer(uint width, uint height) :
 		Texture(width, height) {
 #ifdef SDL_BACKEND
-	if (!isExtensionSupported("GL_EXT_framebuffer_object")) {
+	if (!OpenGLContext.framebufferObjectSupported) {
 		error("GL_EXT_framebuffer_object extension is not supported!");
 	}
 #endif

graphics/opengl/system_headers.h

@@ -41,6 +41,11 @@
 #	define GL_BGRA GL_BGRA_EXT
 #endif
 
+#if !defined(GL_UNPACK_ROW_LENGTH)
+// The Android SDK does not declare GL_UNPACK_ROW_LENGTH_EXT
+#define GL_UNPACK_ROW_LENGTH 0x0CF2
+#endif
+
 #elif defined(USE_GLEW)
 #include <GL/glew.h>
 #elif defined(SDL_BACKEND) && defined(USE_OPENGL)

graphics/opengl/texture.cpp

@@ -25,7 +25,7 @@
 #if defined(USE_OPENGL)
 
 #include "graphics/opengl/texture.h"
-#include "graphics/opengl/extensions.h"
+#include "graphics/opengl/context.h"
 
 
 namespace OpenGL {
@@ -52,7 +52,7 @@ static const Graphics::PixelFormat getRGBAPixelFormat() {
 
 Texture::Texture(const Graphics::Surface &srf) :
 		_managedTexture(true), _width(srf.w), _height(srf.h) {
-	if (isExtensionSupported("GL_ARB_texture_non_power_of_two")) {
+	if (OpenGLContext.NPOTSupported) {
 		_texWidth  = _width;
 		_texHeight = _height;
 	} else {
@@ -80,7 +80,7 @@ Texture::Texture(const Graphics::Surface &srf) :
 
 Texture::Texture(uint width, uint height) :
 		_managedTexture(true), _width(width), _height(height) {
-	if (isExtensionSupported("GL_ARB_texture_non_power_of_two")) {
+	if (OpenGLContext.NPOTSupported) {
 		_texWidth  = _width;
 		_texHeight = _height;
 	} else {