Create half-broken XShm driver, to perform evil experiments on

Makefile.common

@@ -816,6 +816,10 @@ ifeq ($(HAVE_SDL2), 1)
    HAVE_SDL = 0
 endif
 
+ifeq ($(HAVE_XSHM), 1)
+   OBJ += gfx/drivers/xshm_gfx.o
+endif
+
 ifeq ($(HAVE_VULKAN), 1)
    ifneq ($(findstring Win32,$(OS)),)
       GLSLANG_PLATFORM := Windows

gfx/drivers/xshm_gfx.c

@@ -0,0 +1,274 @@
+/*  RetroArch - A frontend for libretro.
+ *  Copyright (C) 2010-2014 - Hans-Kristian Arntzen
+ *  Copyright (C) 2016-2016 - Alfred Agrell
+ *
+ *  RetroArch 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 Found-
+ *  ation, either version 3 of the License, or (at your option) any later version.
+ *
+ *  RetroArch 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 RetroArch.
+ *  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <retro_inline.h>
+#include <gfx/scaler/scaler.h>
+
+#include "../../configuration.h"
+#include "../../driver.h"
+#include "../../retroarch.h"
+#include "../../runloop.h"
+#include "../../performance_counters.h"
+#include "../../verbosity.h"
+#include "../video_context_driver.h"
+#include "../font_driver.h"
+
+#include "../common/x11_common.h"
+
+#ifdef HAVE_MENU
+#include "../../menu/menu_driver.h"
+#endif
+
+#include <sys/shm.h>
+#include <X11/Xlib.h>
+#include <X11/Xutil.h>
+#include <X11/extensions/XShm.h>
+
+
+typedef struct xshm
+{
+   Display* display;
+   Window wndw;
+   
+   int width;
+   int height;
+   
+   XShmSegmentInfo shmInfo;
+   XImage* image;
+   GC gc;
+} xshm_t;
+
+static void *xshm_gfx_init(const video_info_t *video,
+      const input_driver_t **input, void **input_data)
+{
+   xshm_t* xshm = (xshm_t*)malloc(sizeof(xshm_t));
+   
+   XInitThreads();
+   
+   xshm->display = XOpenDisplay(NULL);
+   
+   XSetWindowAttributes attributes;
+   attributes.border_pixel=0;
+   xshm->wndw = XCreateWindow(xshm->display, DefaultRootWindow(xshm->display)/*xshm->parentwindow*/,
+                              0, 0, video->width, video->height,
+                              0, 24, CopyFromParent, NULL, CWBorderPixel, &attributes);
+   XSetWindowBackground(xshm->display, xshm->wndw, 0);
+   XMapWindow(xshm->display, xshm->wndw);
+   
+   xshm->shmInfo.shmid = shmget(IPC_PRIVATE, sizeof(uint32_t) * video->width * video->height,
+                                IPC_CREAT|0600);
+   if (xshm->shmInfo.shmid<0) abort();//seems like an out of memory situation... let's just blow up
+   
+   xshm->shmInfo.shmaddr = (char*)shmat(xshm->shmInfo.shmid, 0, 0);
+   xshm->shmInfo.readOnly = False;
+   XShmAttach(xshm->display, &xshm->shmInfo);
+   XSync(xshm->display, False);//no idea why this is required, but I get weird errors without it
+   xshm->image = XShmCreateImage(xshm->display, NULL, 24, ZPixmap,
+                                 xshm->shmInfo.shmaddr, &xshm->shmInfo, video->width, video->height);
+   
+   xshm->gc = XCreateGC(xshm->display, xshm->wndw, 0, NULL);
+   
+   xshm->width = video->width;
+   xshm->height = video->height;
+   
+   *input = NULL;
+   *input_data = NULL;
+   
+   return xshm;
+}
+
+static bool xshm_gfx_frame(void *data, const void *frame, unsigned width,
+      unsigned height, uint64_t frame_count,
+      unsigned pitch, const char *msg)
+{
+   xshm_t* xshm = (xshm_t*)data;
+   int x, y;
+   
+   for (y=0;y<height;y++)
+   {
+      memcpy((uint8_t*)xshm->shmInfo.shmaddr + sizeof(uint32_t)*xshm->width*y, (uint8_t*)frame + pitch*y, pitch);
+   }
+   
+   XShmPutImage(xshm->display, xshm->wndw, xshm->gc, xshm->image,
+                0, 0, 0, 0, xshm->width, xshm->height, False);
+   XFlush(xshm->display);
+   
+   return true;
+}
+
+static void xshm_gfx_set_nonblock_state(void *data, bool toggle)
+{
+   
+}
+
+static bool xshm_gfx_alive(void *data)
+{
+   return true;
+}
+
+static bool xshm_gfx_focus(void *data)
+{
+   return true;
+}
+
+static bool xshm_gfx_suppress_screensaver(void *data, bool enable)
+{
+   return false;
+}
+
+static bool xshm_gfx_has_windowed(void *data)
+{
+   return true;
+}
+
+static void xshm_gfx_free(void *data)
+{
+   
+}
+
+static void xshm_gfx_set_rotation(void *data, unsigned rotation)
+{
+   
+}
+
+static void xshm_gfx_viewport_info(void *data, struct video_viewport *vp)
+{
+   
+}
+
+static bool xshm_gfx_read_viewport(void *data, uint8_t *buffer)
+{
+   return false;
+}
+
+static void xshm_poke_set_filtering(void *data, unsigned index, bool smooth)
+{
+   
+}
+
+static void xshm_poke_set_aspect_ratio(void *data, unsigned aspect_ratio_idx)
+{
+   
+}
+
+static void xshm_poke_apply_state_changes(void *data)
+{
+   
+}
+
+#ifdef HAVE_MENU
+static void xshm_poke_set_texture_frame(void *data, const void *frame, bool rgb32,
+      unsigned width, unsigned height, float alpha)
+{
+   
+}
+
+static void xshm_poke_texture_enable(void *data, bool enable, bool full_screen)
+{
+   
+}
+
+static void xshm_poke_set_osd_msg(void *data, const char *msg,
+      const struct font_params *params, void *font)
+{
+   
+}
+
+static void xshm_show_mouse(void *data, bool state)
+{
+   
+}
+
+static void xshm_grab_mouse_toggle(void *data)
+{
+   
+}
+#endif
+
+static video_poke_interface_t xshm_video_poke_interface = {
+   NULL,
+   NULL,
+   NULL,
+   xshm_poke_set_filtering,
+   NULL, /* get_video_output_size */
+   NULL, /* get_video_output_prev */
+   NULL, /* get_video_output_next */
+   NULL, /* get_current_framebuffer */
+   NULL, /* get_proc_address */
+   xshm_poke_set_aspect_ratio,
+   xshm_poke_apply_state_changes,
+#ifdef HAVE_MENU
+   xshm_poke_set_texture_frame,
+   xshm_poke_texture_enable,
+   xshm_poke_set_osd_msg,
+   xshm_show_mouse,
+   xshm_grab_mouse_toggle,
+#else
+   NULL,
+   NULL,
+   NULL,
+   NULL,
+   NULL,
+#endif
+   NULL,
+};
+
+static void xshm_gfx_poke_interface(void *data, const video_poke_interface_t **iface)
+{
+   (void)data;
+   *iface = &xshm_video_poke_interface;
+}
+
+static bool xshm_gfx_set_shader(void *data,
+      enum rarch_shader_type type, const char *path)
+{
+   (void)data;
+   (void)type;
+   (void)path;
+
+   return false; 
+}
+
+video_driver_t video_xshm = {
+   xshm_gfx_init,
+   xshm_gfx_frame,
+   xshm_gfx_set_nonblock_state,
+   xshm_gfx_alive,
+   xshm_gfx_focus,
+   xshm_gfx_suppress_screensaver,
+   xshm_gfx_has_windowed,
+   xshm_gfx_set_shader,
+   xshm_gfx_free,
+   "xshm",
+
+   NULL,
+   xshm_gfx_set_rotation,
+   xshm_gfx_viewport_info,
+   xshm_gfx_read_viewport,
+   NULL, /* read_frame_raw */
+#ifdef HAVE_OVERLAY
+    NULL,
+#endif
+    xshm_gfx_poke_interface
+};
+

gfx/video_driver.c

@@ -203,6 +203,9 @@ static const video_driver_t *video_drivers[] = {
 #endif
 #ifdef HAVE_PLAIN_DRM
    &video_drm,
+#endif
+#ifdef HAVE_XSHM
+   &video_xshm,
 #endif
    &video_null,
    NULL,

qb/config.params.sh

@@ -79,7 +79,7 @@ HAVE_PARPORT=auto          # Parallel port joypad support
 HAVE_IMAGEVIEWER=yes       # Built-in image viewer support.
 HAVE_MMAP=auto             # MMAP support
 HAVE_QT=no                 # QT companion support
-HAVE_XSHM=no               # XShm video driver support (disabled because it's just a dummied out stub)
+HAVE_XSHM=auto             # XShm video driver support
 HAVE_CHEEVOS=yes           # Retro Achievements
 HAVE_SHADERPIPELINE=yes    # Additional shader-based pipelines
 C89_SHADERPIPELINE=no