Reimplement monitor capture

- Implement windows monitor capture (code is so much cleaner than in
   OBS1).  Will implement duplication capture later

 - Add GDI texture support to d3d11 graphics library

 - Fix precision issue with sleep timing, you have to call
   timeBeginPeriod otherwise windows sleep will be totally erratic.

libobs/graphics/graphics-imports.c

@@ -167,8 +167,17 @@ bool load_graphics_imports(struct gs_exports *exports, void *module,
 	GRAPHICS_IMPORT(shader_setdefault);
 
 	/* OSX/Cocoa specific functions */
+#ifdef __APPLE__
 	GRAPHICS_IMPORT_OPTIONAL(texture_create_from_iosurface);
 	GRAPHICS_IMPORT_OPTIONAL(texture_rebind_iosurface);
 
+	/* win32 specific functions */
+#elif _WIN32
+	GRAPHICS_IMPORT(gdi_texture_available);
+	GRAPHICS_IMPORT_OPTIONAL(device_create_gdi_texture);
+	GRAPHICS_IMPORT_OPTIONAL(texture_get_dc);
+	GRAPHICS_IMPORT_OPTIONAL(texture_release_dc);
+#endif
+
 	return success;
 }

libobs/graphics/graphics-internal.h

@@ -202,9 +202,19 @@ struct gs_exports {
 			size_t size);
 	void (*shader_setdefault)(shader_t shader, sparam_t param);
 
+#ifdef __APPLE__
 	/* OSX/Cocoa specific functions */
 	texture_t (*texture_create_from_iosurface)(device_t dev, void *iosurf);
 	bool (*texture_rebind_iosurface)(texture_t texture, void *iosurf);
+
+#elif _WIN32
+	bool (*gdi_texture_available)(void);
+	texture_t (*device_create_gdi_texture)(device_t device,
+			uint32_t width, uint32_t height);
+
+	void *(*texture_get_dc)(texture_t gdi_tex);
+	void (*texture_release_dc)(texture_t gdi_tex);
+#endif
 };
 
 struct graphics_subsystem {

libobs/graphics/graphics.c

@@ -1894,6 +1894,8 @@ enum gs_index_type indexbuffer_gettype(indexbuffer_t indexbuffer)
 	return thread_graphics->exports.indexbuffer_gettype(indexbuffer);
 }
 
+#ifdef __APPLE__
+
 /** Platform specific functions */
 texture_t gs_create_texture_from_iosurface(void *iosurf)
 {
@@ -1914,3 +1916,46 @@ bool texture_rebind_iosurface(texture_t texture, void *iosurf)
 
 	return graphics->exports.texture_rebind_iosurface(texture, iosurf);
 }
+
+#elif _WIN32
+
+bool gs_gdi_texture_available(void)
+{
+	if (!thread_graphics)
+		return false;
+
+	return thread_graphics->exports.gdi_texture_available();
+}
+
+/** creates a windows GDI-lockable texture */
+texture_t gs_create_gdi_texture(uint32_t width, uint32_t height)
+{
+	graphics_t graphics = thread_graphics;
+	if (!graphics) return NULL;
+
+	if (graphics->exports.device_create_gdi_texture)
+		return graphics->exports.device_create_gdi_texture(
+				graphics->device, width, height);
+	return NULL;
+}
+
+void *texture_get_dc(texture_t gdi_tex)
+{
+	if (!thread_graphics || !gdi_tex)
+		return NULL;
+
+	if (thread_graphics->exports.texture_get_dc)
+		return thread_graphics->exports.texture_get_dc(gdi_tex);
+	return NULL;
+}
+
+void texture_release_dc(texture_t gdi_tex)
+{
+	if (!thread_graphics || !gdi_tex)
+		return;
+
+	if (thread_graphics->exports.texture_release_dc)
+		thread_graphics->exports.texture_release_dc(gdi_tex);
+}
+
+#endif

libobs/graphics/graphics.h

@@ -677,11 +677,25 @@ EXPORT void     *indexbuffer_getdata(indexbuffer_t indexbuffer);
 EXPORT size_t   indexbuffer_numindices(indexbuffer_t indexbuffer);
 EXPORT enum gs_index_type indexbuffer_gettype(indexbuffer_t indexbuffer);
 
+#ifdef __APPLE__
+
 /** platform specific function for creating (GL_TEXTURE_RECTANGLE) textures
  * from shared surface resources */
 EXPORT texture_t gs_create_texture_from_iosurface(void *iosurf);
 EXPORT bool     texture_rebind_iosurface(texture_t texture, void *iosurf);
 
+#elif _WIN32
+
+EXPORT bool gs_gdi_texture_available(void);
+
+/** creates a windows GDI-lockable texture */
+EXPORT texture_t gs_create_gdi_texture(uint32_t width, uint32_t height);
+
+EXPORT void *texture_get_dc(texture_t gdi_tex);
+EXPORT void texture_release_dc(texture_t gdi_tex);
+
+#endif
+
 /* inline functions used by modules */
 
 static inline uint32_t gs_get_format_bpp(enum gs_color_format format)