Added 'test' directory and a demo program for testing tear-free animation

It is basically the first test program for the sunxi disp ioctls wrapper
code from "src/sunxi_disp.c".
Signed-off-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>

Makefile.am

@@ -18,7 +18,7 @@
 #  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.
 
-SUBDIRS = src man
+SUBDIRS = src test man
 MAINTAINERCLEANFILES = ChangeLog INSTALL
 
 .PHONY: ChangeLog INSTALL

configure.ac

@@ -98,6 +98,7 @@ AC_SUBST([DRIVER_NAME])
 AC_CONFIG_FILES([
                 Makefile
                 src/Makefile
+                test/Makefile
                 man/Makefile
 ])
 AC_OUTPUT

test/Makefile.am

+SUNXI_DISP = ../src/sunxi_disp.c ../src/sunxi_disp.h ../src/sunxi_disp_ioctl.h
+
+DEMOS =				\
+	sunxi_disp_vsync_demo
+
+sunxi_disp_vsync_demo_SOURCES = sunxi_disp_vsync_demo.c $(SUNXI_DISP)
+
+noinst_PROGRAMS = $(DEMOS)

test/sunxi_disp_vsync_demo.c

+/*
+ * Copyright © 2013 Siarhei Siamashka <siarhei.siamashka@gmail.com>
+ *
+ * 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 (including the next
+ * paragraph) 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.
+ */
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <assert.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <linux/fb.h>
+#include <signal.h>
+
+#include "../src/sunxi_disp.h"
+
+void memset32(uint32_t *buf, uint32_t color, int n)
+{
+    while (n--) {
+        *buf++ = color;
+    }
+}
+
+void fill_framebuffer(void *buf_, int pitch, int height,
+                      int bw_split_pos, uint32_t color)
+{
+    uint32_t *buf = (uint32_t *)buf_;
+    int i;
+    while (height--) {
+        memset32(buf, color, bw_split_pos);
+        memset32(buf + bw_split_pos, 0x00, pitch - bw_split_pos);
+        buf += pitch;
+    }
+}
+
+static sunxi_disp_t *disp;
+
+void disp_destructor(int signum)
+{
+    printf("\nsunxi_disp_close()\n");
+    if (disp) {
+        sunxi_disp_close(disp);
+        disp = NULL;
+    }
+    exit(0);
+}
+
+int main(int argc, char *argv[])
+{
+    int pos = 0, framenum = 0, yoffs, color;
+
+    disp = sunxi_disp_init("/dev/fb0");
+    /*
+     * setup the signal handler to catch Ctrl-C in order to prevent leaking
+     * the layer on process termination (that's a kernel bug).
+     */
+    signal(SIGINT, disp_destructor);
+
+    if (!disp) {
+        printf("sunxi_disp_init() failed\n");
+        exit(1);
+    }
+
+    printf("disp->xres=%d, disp->yres=%d, disp_bits_per_pixel=%d\n",
+           disp->xres, disp->yres, disp->bits_per_pixel);
+
+    if (disp->bits_per_pixel != 32) {
+        printf("Sorry, only 32 bits per pixel is supported for now\n");
+        exit(1);
+    }
+
+    if (disp->framebuffer_size < disp->xres * disp->yres * 4 * 2) {
+        printf("Sorry, framebuffer size is too small (need at least %.1f MiB)\n",
+               (double)disp->xres * disp->yres * 4 * 2 / (1024 * 1024));
+        exit(1);
+    }
+
+    printf("\nYou should see some tear-free animation where the left half\n");
+    printf("of the screen is filled with yellow color, the right half of the\n");
+    printf("screen is black and the border between yellow and black areas is\n");
+    printf("moving and bouncing between left and right sides of the screen.\n\n");
+
+    printf("In the case if vsync is broken, you may see some blue colored\n");
+    printf("areas or tearing in the vertical line separating yellow and black.\n\n");
+
+    printf("This demo can be stopped by pressing Ctrl-C.\n");
+
+    /* setup layer window to cover the whole screen */
+    sunxi_layer_set_output_window(disp, 0, 0, disp->xres, disp->yres);
+    /* setup the layer scanout buffer to the first page in the framebuffer */
+    sunxi_layer_set_x8r8g8b8_input_buffer(disp, 0, disp->xres, disp->yres, disp->xres);
+    /* make the layer visible */
+    sunxi_layer_show(disp);
+
+    while (1) {
+        if (framenum % 2 == 1) {
+            color = 0xFFFFFF00;
+            yoffs = 0;
+        } else {
+            color = 0xFFFFFF00;
+            yoffs = disp->yres;
+        }
+        pos = (pos + 16) % (disp->xres * 2);
+
+        /* paint part of the screen with blue in the offscreen buffer */
+        fill_framebuffer(disp->framebuffer_addr + yoffs * disp->xres * 4,
+                         disp->xres, disp->yres,
+                         pos < disp->xres ? pos : 2 * disp->xres - pos,
+                         0xFF0000FF);
+
+        /* paint part of the screen with yellow in the offscreen buffer */
+        fill_framebuffer(disp->framebuffer_addr + yoffs * disp->xres * 4,
+                         disp->xres, disp->yres,
+                         pos < disp->xres ? pos : 2 * disp->xres - pos,
+                         color);
+
+        /* schedule the change of layer scanout buffer on next vsync */
+        sunxi_layer_set_x8r8g8b8_input_buffer(disp, yoffs * disp->xres * 4,
+                                              disp->xres, disp->yres, disp->xres);
+        /* wait for the vsync itself */
+        ioctl(disp->fd_fb, FBIO_WAITFORVSYNC, 0);
+
+        framenum++;
+    }
+
+    return 0;
+}