add sokol_glue.h header

sokol_glue.h

@@ -0,0 +1,132 @@
+#ifndef SOKOL_GLUE_INCLUDED
+/*
+    sokol_glue.h -- glue helper functions for sokol headers
+
+    Project URL: https://github.com/floooh/sokol
+
+    Do this:
+        #define SOKOL_IMPL
+    before you include this file in *one* C or C++ file to create the
+    implementation.
+
+    ...optionally provide the following macros to override defaults:
+
+    SOKOL_ASSERT(c)     - your own assert macro (default: assert(c))
+    SOKOL_API_DECL      - public function declaration prefix (default: extern)
+    SOKOL_API_IMPL      - public function implementation prefix (default: -)
+
+    If sokol_glue.h is compiled as a DLL, define the following before
+    including the declaration or implementation:
+
+    SOKOL_DLL
+
+    On Windows, SOKOL_DLL will define SOKOL_API_DECL as __declspec(dllexport)
+    or __declspec(dllimport) as needed.
+
+    OVERVIEW
+    ========
+    The sokol core headers should not depend on each other, but sometimes
+    it's useful to have a set of helper functions as "glue" between
+    two or more sokol headers.
+
+    This is what sokol_glue.h is for. Simply include the header after other
+    sokol headers (both for the implementation and declaration), and
+    depending on what headers have been included before, sokol_glue.h
+    will make available "glue functions".
+
+    PROVIDED FUNCTIONS
+    ==================
+
+    - if sokol_app.h and sokol_gfx.h is included:
+
+        sg_context_desc sapp_sgcontext(void):
+
+            Returns an initialized sg_context_desc function initialized
+            by calling sokol_app.h functions.
+
+    LICENSE
+    =======
+    zlib/libpng license
+
+    Copyright (c) 2018 Andre Weissflog
+
+    This software is provided 'as-is', without any express or implied warranty.
+    In no event will the authors be held liable for any damages arising from the
+    use of this software.
+
+    Permission is granted to anyone to use this software for any purpose,
+    including commercial applications, and to alter it and redistribute it
+    freely, subject to the following restrictions:
+
+        1. The origin of this software must not be misrepresented; you must not
+        claim that you wrote the original software. If you use this software in a
+        product, an acknowledgment in the product documentation would be
+        appreciated but is not required.
+
+        2. Altered source versions must be plainly marked as such, and must not
+        be misrepresented as being the original software.
+
+        3. This notice may not be removed or altered from any source
+        distribution.
+*/
+#define SOKOL_GLUE_INCLUDED
+
+#ifndef SOKOL_API_DECL
+#if defined(_WIN32) && defined(SOKOL_DLL) && defined(SOKOL_IMPL)
+#define SOKOL_API_DECL __declspec(dllexport)
+#elif defined(_WIN32) && defined(SOKOL_DLL)
+#define SOKOL_API_DECL __declspec(dllimport)
+#else
+#define SOKOL_API_DECL extern
+#endif
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#if defined(SOKOL_GFX_INCLUDED) && defined(SOKOL_APP_INCLUDED)
+SOKOL_API_DECL sg_context_desc sapp_sgcontext(void);
+#endif
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+#endif /* SOKOL_GLUE_INCLUDED */
+
+/*-- IMPLEMENTATION ----------------------------------------------------------*/
+#ifdef SOKOL_IMPL
+#define SOKOL_GLUE_IMPL_INCLUDED (1)
+#include <string.h> /* memset */
+
+#ifndef SOKOL_API_IMPL
+    #define SOKOL_API_IMPL
+#endif
+
+#if defined(SOKOL_GFX_INCLUDED) && defined(SOKOL_APP_INCLUDED)
+SOKOL_API_IMPL sg_context_desc sapp_sgcontext(void) {
+    SOKOL_ASSERT(SAPP_PIXELFORMAT_RGBA8 == SG_PIXELFORMAT_RGBA8);
+    SOKOL_ASSERT(SAPP_PIXELFORMAT_BGRA8 == SG_PIXELFORMAT_BGRA8);
+    SOKOL_ASSERT(SAPP_PIXELFORMAT_DEPTH == SG_PIXELFORMAT_DEPTH);
+    SOKOL_ASSERT(SAPP_PIXELFORMAT_DEPTH_STENCIL == SG_PIXELFORMAT_DEPTH_STENCIL);
+    sg_context_desc desc;
+    memset(&desc, 0, sizeof(desc));
+    desc.color_format = sapp_color_format();
+    desc.depth_format = sapp_depth_format();
+    desc.gl.force_gles2 = sapp_gles2();
+    desc.metal.device = sapp_metal_get_device();
+    desc.metal.renderpass_descriptor_cb = sapp_metal_get_renderpass_descriptor;
+    desc.metal.drawable_cb = sapp_metal_get_drawable;
+    desc.d3d11.device = sapp_d3d11_get_device();
+    desc.d3d11.device_context = sapp_d3d11_get_device_context();
+    desc.d3d11.render_target_view_cb = sapp_d3d11_get_render_target_view;
+    desc.d3d11.depth_stencil_view_cb = sapp_d3d11_get_depth_stencil_view;
+    desc.wgpu.device = sapp_wgpu_get_device();
+    desc.wgpu.render_view_cb = sapp_wgpu_get_render_view;
+    desc.wgpu.resolve_view_cb = sapp_wgpu_get_resolve_view;
+    desc.wgpu.depth_stencil_view_cb = sapp_wgpu_get_depth_stencil_view;
+    return desc;
+}
+#endif
+
+#endif /* SOKOL_IMPL */