pixman: helper functions

Add some helper functions which will be put
into use by following patches.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

Makefile.objs

@@ -65,6 +65,7 @@ common-obj-y = $(block-obj-y) blockdev.o blockdev-nbd.o block/
 common-obj-y += net.o net/
 common-obj-y += qom/
 common-obj-y += readline.o console.o cursor.o
+common-obj-y += qemu-pixman.o
 common-obj-y += $(oslib-obj-y)
 common-obj-$(CONFIG_WIN32) += os-win32.o
 common-obj-$(CONFIG_POSIX) += os-posix.o

qemu-pixman.c

+#include "qemu-pixman.h"
+
+int qemu_pixman_get_type(int rshift, int gshift, int bshift)
+{
+    int type = PIXMAN_TYPE_OTHER;
+
+    if (rshift > gshift && gshift > bshift) {
+        if (bshift == 0) {
+            type = PIXMAN_TYPE_ARGB;
+        } else {
+#if PIXMAN_VERSION >= PIXMAN_VERSION_ENCODE(0, 21, 8)
+            type = PIXMAN_TYPE_RGBA;
+#endif
+        }
+    } else if (rshift < gshift && gshift < bshift) {
+        if (rshift == 0) {
+            type = PIXMAN_TYPE_ABGR;
+        } else {
+            type = PIXMAN_TYPE_BGRA;
+        }
+    }
+    return type;
+}
+
+pixman_format_code_t qemu_pixman_get_format(PixelFormat *pf)
+{
+    pixman_format_code_t format;
+    int type;
+
+    type = qemu_pixman_get_type(pf->rshift, pf->gshift, pf->bshift);
+    format = PIXMAN_FORMAT(pf->bits_per_pixel, type,
+                           pf->abits, pf->rbits, pf->gbits, pf->bbits);
+    if (!pixman_format_supported_source(format)) {
+        return 0;
+    }
+    return format;
+}
+
+pixman_image_t *qemu_pixman_linebuf_create(pixman_format_code_t format,
+                                           int width)
+{
+    pixman_image_t *image = pixman_image_create_bits(format, width, 1, NULL, 0);
+    assert(image != NULL);
+    return image;
+}
+
+void qemu_pixman_linebuf_fill(pixman_image_t *linebuf, pixman_image_t *fb,
+                              int width, int y)
+{
+    pixman_image_composite(PIXMAN_OP_SRC, fb, NULL, linebuf,
+                           0, y, 0, 0, 0, 0, width, 1);
+}
+
+void qemu_pixman_image_unref(pixman_image_t *image)
+{
+    if (image == NULL) {
+        return;
+    }
+    pixman_image_unref(image);
+}

qemu-pixman.h

+#ifndef QEMU_PIXMAN_H
+#define QEMU_PIXMAN_H
+
+#include <pixman.h>
+
+#include "console.h"
+
+/*
+ * pixman image formats are defined to be native endian,
+ * that means host byte order on qemu.  So we go define
+ * fixed formats here for cases where it is needed, like
+ * feeding libjpeg / libpng and writing screenshots.
+ */
+
+#ifdef HOST_WORDS_BIGENDIAN
+# define PIXMAN_BE_r8g8b8     PIXMAN_r8g8b8
+#else
+# define PIXMAN_BE_r8g8b8     PIXMAN_b8g8r8
+#endif
+
+/* -------------------------------------------------------------------- */
+
+int qemu_pixman_get_type(int rshift, int gshift, int bshift);
+pixman_format_code_t qemu_pixman_get_format(PixelFormat *pf);
+
+pixman_image_t *qemu_pixman_linebuf_create(pixman_format_code_t format,
+                                           int width);
+void qemu_pixman_linebuf_fill(pixman_image_t *linebuf, pixman_image_t *fb,
+                              int width, int y);
+void qemu_pixman_image_unref(pixman_image_t *image);
+
+#endif /* QEMU_PIXMAN_H */