From 88391c47d2580b14c1d52f4238ce1707f8f3de7b Mon Sep 17 00:00:00 2001
From: Vincent Wei <vincent@minigui.org>
Date: Fri, 20 Mar 2020 19:11:00 +0800
Subject: [PATCH] implement GAL_CreateRGBSurfaceInShm

---
 src/newgal/surface-shm.c | 175 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 175 insertions(+)
 create mode 100644 src/newgal/surface-shm.c

diff --git a/src/newgal/surface-shm.c b/src/newgal/surface-shm.c
new file mode 100644
index 00000000..06da14a2
--- /dev/null
+++ b/src/newgal/surface-shm.c
@@ -0,0 +1,175 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+//                          IMPORTANT NOTICE
+//
+// The following open source license statement does not apply to any
+// entity in the Exception List published by FMSoft.
+//
+// For more information, please visit:
+//
+// https://www.fmsoft.cn/exception-list
+//
+//////////////////////////////////////////////////////////////////////////////
+/*
+ *   This file is part of MiniGUI, a mature cross-platform windowing
+ *   and Graphics User Interface (GUI) support system for embedded systems
+ *   and smart IoT devices.
+ *
+ *   Copyright (C) 2002~2020, Beijing FMSoft Technologies Co., Ltd.
+ *   Copyright (C) 1998~2002, WEI Yongming
+ *
+ *   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 3 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, see <http://www.gnu.org/licenses/>.
+ *
+ *   Or,
+ *
+ *   As this program is a library, any link to this program must follow
+ *   GNU General Public License version 3 (GPLv3). If you cannot accept
+ *   GPLv3, you need to be licensed from FMSoft.
+ *
+ *   If you have got a commercial license of this program, please use it
+ *   under the terms and conditions of the commercial license.
+ *
+ *   For more information about the commercial license, please refer to
+ *   <http://www.minigui.com/blog/minigui-licensing-policy/>.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define _DEBUG
+
+#include "common.h"
+#include "minigui.h"
+#include "constants.h"
+
+#ifdef _MGRM_PROCESSES
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <fcntl.h>           /* For O_* constants */
+#include <unistd.h>
+
+#include "misc.h"
+#include "newgal.h"
+
+/*
+ * Create a RGB surface in shared memory in the appropriate depth and pixel format
+ */
+GAL_Surface * GAL_CreateRGBSurfaceInShm (const char* shm_name, BOOL create,
+        Uint32 rw_modes, Uint32 hdr_size, int width, int height, int depth,
+        Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask)
+{
+    int fd = -1, pitch;
+    size_t map_size, offset;
+    uint8_t* buff = NULL;
+    GAL_Surface* surface = NULL;
+
+    if (width <= 0 || height <= 0)
+        return NULL;
+
+    if (create) {
+        fd = shm_open (shm_name, O_CREAT | O_RDWR | O_CLOEXEC, rw_modes);
+    }
+    else {
+        fd = shm_open (shm_name, O_RDWR | O_CLOEXEC, rw_modes);
+    }
+
+    if (fd <= 0) {
+        _DBG_PRINTF ("failed to call shm_open: %m\n");
+        return NULL;
+    }
+
+    pitch = width * ((depth + 7) / 8);
+    pitch = (pitch + 3) & ~3;
+
+    if (hdr_size) {
+        int nr_hdr_lines = hdr_size / pitch;
+        if (hdr_size % pitch)
+            nr_hdr_lines++;
+
+        map_size = pitch * (height + nr_hdr_lines);
+        offset = pitch * nr_hdr_lines;
+    }
+    else {
+        map_size = pitch * height;
+        offset = 0;
+    }
+
+    _DBG_PRINTF ("map_size for depth (%d), width (%d), height (%d): %lu\n",
+            depth, width, height, map_size);
+
+    if (create && ftruncate (fd, map_size)) {
+        close (fd);
+        _DBG_PRINTF ("failed to call ftruncate: %m\n");
+        goto error;
+    }
+    else {
+        off_t file_size = lseek (fd, 0, SEEK_END);
+        if (file_size != map_size) {
+            _DBG_PRINTF ("file size (%lu) does not match the map size (%lu), "
+                    "width (%d), height (%d), depth (%d)\n",
+                    file_size, map_size, width, height, depth);
+            goto error;
+        }
+    }
+
+    buff = mmap (NULL, map_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+    if (buff == MAP_FAILED) {
+        _DBG_PRINTF ("failed to call mmap: %m\n");
+        buff = NULL;
+        goto error;
+    }
+
+    /* create a null size software surface first */
+    surface = GAL_CreateRGBSurface (GAL_SWSURFACE, 0, 0, depth,
+            Rmask, Gmask, Bmask, Amask);
+    if (surface == NULL) {
+        _DBG_PRINTF ("failed to create null surface\n");
+        goto error;
+    }
+
+    /* Get the pixels */
+    surface->flags |= GAL_PREALLOC;
+    surface->w = width;
+    surface->h = height;
+    surface->pitch = pitch;
+    surface->pixels_off = offset;
+    surface->pixels = buff + offset;
+    surface->hwdata = (void*)map_size;  // use hwdata for map_size
+
+    close (fd);
+    return surface;
+
+error:
+    if (surface) {
+        surface->pixels = NULL;
+        GAL_FreeSurface (surface);
+    }
+
+    if (buff) {
+        munmap (buff, map_size);
+    }
+
+    if (fd >= 0) {
+        close (fd);
+        shm_unlink (shm_name);
+    }
+
+    return NULL;
+}
+
+#endif /* defined _MGRM_PROCESSES */
+