[Spice-devel] [PATCH v3 spice-gtk 2/2] channel-cursor: mono cursors edge highlighting
Alon Levy
alevy at redhat.com
Sat Oct 19 18:16:46 CEST 2013
Fix 998529, mono (invert) cursors not visible on a black background, by doing
simple edge detection on the cursor (this is done once when the cursor
is changed and then cached, cursors are 32x32 generally) and thus having
a cursor with contrast on both dark and light backgrounds.
When (if) GDK gets invert cursor support (wayland?) then we can just use
the cursor as is. Until then X doesn't provide any way I see of solving
this otherwise. The end result was tested with the I beam cursor that
the original bug was referring to (run putty on a windows 7 vm) and
looks ok to me.
Moving the core function to spice-util for testing.
---
gtk/channel-cursor.c | 64 +++------------------------
gtk/spice-util-priv.h | 2 +
gtk/spice-util.c | 112 +++++++++++++++++++++++++++++++++++++++++++++++
tests/util.c | 117 ++++++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 237 insertions(+), 58 deletions(-)
diff --git a/gtk/channel-cursor.c b/gtk/channel-cursor.c
index 66e91df..e056b30 100644
--- a/gtk/channel-cursor.c
+++ b/gtk/channel-cursor.c
@@ -277,70 +277,18 @@ static void print_cursor(display_cursor *cursor, const guint8 *data)
static void mono_cursor(display_cursor *cursor, const guint8 *data)
{
+ int bpl = (cursor->hdr.width + 7) / 8;
const guint8 *xor, *and;
guint8 *dest;
- int bpl, x, y, bit;
+ dest = (uint8_t *)cursor->data;
- bpl = (cursor->hdr.width + 7) / 8;
- and = data;
- xor = and + bpl * cursor->hdr.height;
- dest = (uint8_t *)cursor->data;
#ifdef DEBUG_CURSOR
print_cursor(cursor, data);
#endif
- for (y = 0; y < cursor->hdr.height; y++) {
- bit = 0x80;
- for (x = 0; x < cursor->hdr.width; x++, dest += 4) {
- if (and[x/8] & bit) {
- if (xor[x/8] & bit) {
- /*
- * flip -> unsupported by x11, since XCreatePixmapCursor has
- * no invert functionality, only a mask, shape, background and
- * foreground colors. Use this checkerboard hack to get some
- * contrast for cursors in the guest that relied on invert for
- * the same contrast.
- */
- if ((x ^ y) & 1) {
- dest[0] = 0xff;
- dest[1] = 0xff;
- dest[2] = 0xff;
- dest[3] = 0xff;
- } else {
- dest[0] = 0x00;
- dest[1] = 0x00;
- dest[2] = 0x00;
- dest[3] = 0x00;
- }
- } else {
- /* unchanged -> transparent */
- dest[0] = 0x00;
- dest[1] = 0x00;
- dest[2] = 0x00;
- dest[3] = 0x00;
- }
- } else {
- if (xor[x/8] & bit) {
- /* set -> white */
- dest[0] = 0xff;
- dest[1] = 0xff;
- dest[2] = 0xff;
- dest[3] = 0xff;
- } else {
- /* clear -> black */
- dest[0] = 0x00;
- dest[1] = 0x00;
- dest[2] = 0x00;
- dest[3] = 0xff;
- }
- }
- bit >>= 1;
- if (bit == 0) {
- bit = 0x80;
- }
- }
- and += bpl;
- xor += bpl;
- }
+ and = data;
+ xor = and + bpl * cursor->hdr.height;
+ spice_mono_edge_highlight(cursor->hdr.width, cursor->hdr.height,
+ and, xor, dest);
}
static guint8 get_pix_mask(const guint8 *data, gint offset, gint pix_index)
diff --git a/gtk/spice-util-priv.h b/gtk/spice-util-priv.h
index cc559dc..7f0df3c 100644
--- a/gtk/spice-util-priv.h
+++ b/gtk/spice-util-priv.h
@@ -31,6 +31,8 @@ const gchar* spice_yes_no(gboolean value);
guint16 spice_make_scancode(guint scancode, gboolean release);
gchar* spice_unix2dos(const gchar *str, gssize len, GError **error);
gchar* spice_dos2unix(const gchar *str, gssize len, GError **error);
+void spice_mono_edge_highlight(unsigned width, unsigned hight,
+ const guint8 *and, const guint8 *xor, guint8 *dest);
#if GLIB_CHECK_VERSION(2,32,0)
#define STATIC_MUTEX GMutex
diff --git a/gtk/spice-util.c b/gtk/spice-util.c
index 21dfced..8810a19 100644
--- a/gtk/spice-util.c
+++ b/gtk/spice-util.c
@@ -20,6 +20,7 @@
# include "config.h"
#endif
+#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <glib.h>
@@ -374,3 +375,114 @@ gchar* spice_unix2dos(const gchar *str, gssize len, GError **error)
NEWLINE_TYPE_CR_LF,
error);
}
+
+static bool buf_is_ones(unsigned size, const guint8 *data)
+{
+ int i;
+
+ for (i = 0 ; i < size; ++i) {
+ if (data[i] != 0xff) {
+ return false;
+ }
+ }
+ return true;
+}
+
+static bool is_edge_helper(const guint8 *xor, int bpl, int x, int y)
+{
+ return (xor[bpl * y + (x / 8)] & (0x80 >> (x % 8))) > 0;
+}
+
+static bool is_edge(unsigned width, unsigned height, const guint8 *xor, int bpl, int x, int y)
+{
+ if (x == 0 || x == width -1 || y == 0 || y == height - 1) {
+ return 0;
+ }
+#define P(x, y) is_edge_helper(xor, bpl, x, y)
+ return !P(x, y) && (P(x - 1, y + 1) || P(x, y + 1) || P(x + 1, y + 1) ||
+ P(x - 1, y) || P(x + 1, y) ||
+ P(x - 1, y - 1) || P(x, y - 1) || P(x + 1, y - 1));
+#undef P
+}
+
+/* Mono cursors have two places, "and" and "xor". If a bit is 1 in both, it
+ * means invertion of the corresponding pixel in the display. Since X11 (and
+ * gdk) doesn't do invertion, instead we do edge detection and turn the
+ * sorrounding edge pixels black, and the invert-me pixels white. To
+ * illustrate:
+ *
+ * and xor dest RGB (1=0xffffff, 0=0x000000)
+ *
+ * dest alpha (1=0xff, 0=0x00)
+ *
+ * 11111 00000 00000 00000
+ * 11111 00000 00000 01110
+ * 11111 00100 => 00100 01110
+ * 11111 00100 00100 01110
+ * 11111 00000 00000 01110
+ * 11111 00000 00000 00000
+ *
+ * See tests/util.c for more tests
+ *
+ * Notes:xi
+ * Assumes width >= 8 (i.e. bytes per line is at least 1)
+ * Assumes edges are not on the boundary (first/last line/column) for simplicity
+ *
+ */
+G_GNUC_INTERNAL
+void spice_mono_edge_highlight(unsigned width, unsigned height,
+ const guint8 *and, const guint8 *xor, guint8 *dest)
+{
+ int bpl = (width + 7) / 8;
+ bool and_ones = buf_is_ones(height * bpl, and);
+ int x, y, bit;
+ const guint8 *xor_base = xor;
+
+ for (y = 0; y < height; y++) {
+ bit = 0x80;
+ for (x = 0; x < width; x++, dest += 4) {
+ if (is_edge(width, height, xor_base, bpl, x, y) && and_ones) {
+ dest[0] = 0x00;
+ dest[1] = 0x00;
+ dest[2] = 0x00;
+ dest[3] = 0xff;
+ goto next_bit;
+ }
+ if (and[x/8] & bit) {
+ if (xor[x/8] & bit) {
+ dest[0] = 0xff;
+ dest[1] = 0xff;
+ dest[2] = 0xff;
+ dest[3] = 0xff;
+ } else {
+ /* unchanged -> transparent */
+ dest[0] = 0x00;
+ dest[1] = 0x00;
+ dest[2] = 0x00;
+ dest[3] = 0x00;
+ }
+ } else {
+ if (xor[x/8] & bit) {
+ /* set -> white */
+ dest[0] = 0xff;
+ dest[1] = 0xff;
+ dest[2] = 0xff;
+ dest[3] = 0xff;
+ } else {
+ /* clear -> black */
+ dest[0] = 0x00;
+ dest[1] = 0x00;
+ dest[2] = 0x00;
+ dest[3] = 0xff;
+ }
+ }
+ next_bit:
+ bit >>= 1;
+ if (bit == 0) {
+ bit = 0x80;
+ }
+ }
+ and += bpl;
+ xor += bpl;
+ }
+}
diff --git a/tests/util.c b/tests/util.c
index 86109aa..922818a 100644
--- a/tests/util.c
+++ b/tests/util.c
@@ -78,12 +78,129 @@ static void test_unix2dos(void)
}
}
+static const struct {
+ unsigned width;
+ unsigned height;
+ guint8 *and;
+ guint8 *xor;
+ guint8 *dest;
+} mono[] = {
+ {
+ 8, 6,
+ "11111111"
+ "11111111"
+ "11111111"
+ "11111111"
+ "11111111"
+ "11111111"
+ ,
+ "00000000"
+ "00000000"
+ "00000100"
+ "00000100"
+ "00000000"
+ "00000000"
+ ,
+ "0000" "0000" "0000" "0000" "0000" "0000" "0000" "0000"
+ "0000" "0000" "0000" "0000" "0001" "0001" "0001" "0000"
+ "0000" "0000" "0000" "0000" "0001" "1111" "0001" "0000"
+ "0000" "0000" "0000" "0000" "0001" "1111" "0001" "0000"
+ "0000" "0000" "0000" "0000" "0001" "0001" "0001" "0000"
+ "0000" "0000" "0000" "0000" "0000" "0000" "0000" "0000"
+ }
+};
+
+static void set_bit(guint8 *d, unsigned bit, unsigned value)
+{
+ if (value) {
+ *d |= (0x80 >> bit);
+ } else {
+ *d &= ~(0x80 >> bit);
+ }
+}
+
+static void test_set_bit(void)
+{
+ struct {
+ unsigned len;
+ guint8 *src;
+ guint8 *dest;
+ } tests[] = {
+ {
+ 4,
+ "1111",
+ "\xf0",
+ },
+ {
+ 16,
+ "1111011100110001",
+ "\xf7\x31",
+ }
+ };
+ int i, j, bit;
+ guint8 *dest;
+ int bytes;
+
+ for (i = 0 ; i < G_N_ELEMENTS(tests); ++i) {
+ bytes = (tests[i].len + 7) / 8;
+ dest = g_malloc0(bytes);
+ for (j = 0 ; j < tests[i].len;) {
+ for (bit = 0 ; bit < 8 && j < tests[i].len; ++bit, ++j) {
+ set_bit(&dest[j / 8], bit, tests[i].src[j] == '0' ? 0 : 1);
+ }
+ }
+ for (j = 0 ; j < bytes; ++j) {
+ g_assert(dest[j] == tests[i].dest[j]);
+ }
+ g_free(dest);
+ }
+}
+
+static void test_mono_edge_highlight(void)
+{
+ int i, j, bit;
+ guint8 *and;
+ guint8 *xor;
+ guint8 *dest;
+ guint8 *dest_correct;
+ int size, pixels;
+
+ test_set_bit();
+
+ for (i = 0 ; i < G_N_ELEMENTS(mono); ++i) {
+ pixels = mono[i].width * mono[i].height;
+ size = (pixels + 7) / 8;
+ and = g_malloc0(size);
+ xor = g_malloc0(size);
+ dest = g_malloc0(pixels * 4);
+ dest_correct = g_malloc(pixels * 4);
+ for (j = 0 ; j < pixels;) {
+ for (bit = 0; bit < 8 && j < pixels; ++bit, ++j) {
+ set_bit(&and[j / 8], bit, mono[i].and[j] == '0' ? 0 : 1);
+ set_bit(&xor[j / 8], bit, mono[i].xor[j] == '0' ? 0 : 1);
+ }
+ }
+ for (j = 0 ; j < pixels * 4 ; ++j) {
+ dest_correct[j] = mono[i].dest[j] == '0' ? 0x00 : 0xff;
+ }
+ spice_mono_edge_highlight(mono[i].width, mono[i].height, and, xor, dest);
+ for (j = 0; j < pixels; ++j) {
+ g_assert(dest[j] == dest_correct[j]);
+ }
+ g_free(and);
+ g_free(xor);
+ g_free(dest);
+ g_free(dest_correct);
+ }
+}
+
int main(int argc, char* argv[])
{
g_test_init(&argc, &argv, NULL);
g_test_add_func("/util/dos2unix", test_dos2unix);
g_test_add_func("/util/unix2dos", test_unix2dos);
+ g_test_add_func("/util/mono_edge_highlight", test_mono_edge_highlight);
return g_test_run ();
}
--
1.8.3.1
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