OPENGL: Resolve OpenGL functions on run-time.

Formerly we relied on static linkage. However, in the presense of modern
OpenGL (ES) implementations it is not easily identifable which library to link
against. For example, on Linux amd64 with nVidia drivers and SDL2 setup to
create a GLES 1.1 context one would need to link against libGL.so. However,
traditionally GLES 1.1 required to link against libGLESv1_CM.so. To prevent a
huge mess we simply resolve the OpenGL functions on run-time now and stop
linking against a static library (in most cases).

GLES support needs to be enabled manually on configure time for now.

Tizen changes have NOT been tested.

1 files changed, 97 insertions, 0 deletions

diff --git a/backends/graphics/opengl/opengl-func.h b/backends/graphics/opengl/opengl-func.h
new file mode 100644
index 0000000000..75bc0b4e81
--- /dev/null
+++ b/backends/graphics/opengl/opengl-func.h
@@ -0,0 +1,97 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM 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.
+ *
+ */
+
+/* This file is based on Mesa 3-D's gl.h and GLES/gl.h from Khronos Registry.
+ *
+ * Mesa 3-D's gl.h file is distributed under the following license:
+ * Mesa 3-D graphics library
+ *
+ * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
+ * Copyright (C) 2009  VMware, Inc.  All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ *
+ * GLES/gl.h from Khronos Registry is distributed under the following license:
+ * This document is licensed under the SGI Free Software B License Version
+ * 2.0. For details, see http://oss.sgi.com/projects/FreeB/ .
+ */
+
+/*
+ * This file is a template file to be used inside specific locations in the
+ * OpenGL graphics code. It is not to be included otherwise. It intentionally
+ * does not contain include guards because it can be required to include it
+ * multiple times in a source file.
+ *
+ * Functions are defined by two different user supplied macros:
+ * GL_FUNC_DEF: Define a (builtin) OpenGL (ES) function.
+ * GL_EXT_FUNC_DEF: Define an OpenGL (ES) extension function.
+ */
+
+GL_FUNC_DEF(void, glEnable, (GLenum cap));
+GL_FUNC_DEF(void, glDisable, (GLenum cap));
+GL_FUNC_DEF(void, glClear, (GLbitfield mask));
+GL_FUNC_DEF(void, glColor4f, (GLfloat red, GLfloat green, GLfloat blue, GLfloat alpha));
+GL_FUNC_DEF(void, glViewport, (GLint x, GLint y, GLsizei width, GLsizei height));
+GL_FUNC_DEF(void, glMatrixMode, (GLenum mode));
+GL_FUNC_DEF(void, glLoadIdentity, ());
+#ifdef USE_GLES
+GL_FUNC_DEF(void, glOrthof, (GLfloat left, GLfloat right, GLfloat bottom, GLfloat top, GLfloat zNear, GLfloat zFar));
+#else
+GL_FUNC_DEF(void, glOrtho, (GLdouble left, GLdouble right, GLdouble bottom, GLdouble top, GLdouble near_val, GLdouble far_val));
+#endif
+GL_FUNC_DEF(void, glShadeModel, (GLenum mode));
+GL_FUNC_DEF(void, glHint, (GLenum target, GLenum mode));
+GL_FUNC_DEF(void, glClearColor, (GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha));
+GL_FUNC_DEF(void, glBlendFunc, (GLenum sfactor, GLenum dfactor));
+GL_FUNC_DEF(void, glEnableClientState, (GLenum array));
+GL_FUNC_DEF(void, glPixelStorei, (GLenum pname, GLint param));
+GL_FUNC_DEF(void, glScissor, (GLint x, GLint y, GLsizei width, GLsizei height));
+GL_FUNC_DEF(void, glReadPixels, (GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, GLvoid *pixels));
+GL_FUNC_DEF(void, glGetIntegerv, (GLenum pname, GLint *params));
+GL_FUNC_DEF(void, glDeleteTextures, (GLsizei n, const GLuint *textures));
+GL_FUNC_DEF(void, glGenTextures, (GLsizei n, GLuint *textures));
+GL_FUNC_DEF(void, glBindTexture, (GLenum target, GLuint texture));
+GL_FUNC_DEF(void, glTexParameteri, (GLenum target, GLenum pname, GLint param));
+GL_FUNC_DEF(void, glTexImage2D, (GLenum target, GLint level, GLint internalformat, GLsizei width, GLsizei height, GLint border, GLenum format, GLenum type, const GLvoid *pixels));
+GL_FUNC_DEF(void, glTexCoordPointer, (GLint size, GLenum type, GLsizei stride, const GLvoid *pointer));
+GL_FUNC_DEF(void, glVertexPointer, (GLint size, GLenum type, GLsizei stride, const GLvoid *pointer));
+GL_FUNC_DEF(void, glDrawArrays, (GLenum mode, GLint first, GLsizei count));
+GL_FUNC_DEF(void, glTexSubImage2D, (GLenum target, GLint level, GLint xoffset, GLint yoffset, GLsizei width, GLsizei height, GLenum format, GLenum type, const GLvoid *pixels));
+GL_FUNC_DEF(const GLubyte *, glGetString, (GLenum name));
+GL_FUNC_DEF(GLenum, glGetError, ());