Add a skia demo backend

Note that this then requires us to be C++ clean.

9 files changed, 241 insertions, 17 deletions

diff --git a/Makefile b/Makefile
index 64fdabe..bf8711f 100644
--- a/Makefile
+++ b/Makefile
@@ -46,6 +46,15 @@ else
 DEFINES+=-DHAVE_COGL=0
 endif
 
+SKIA:=$(shell pkg-config --exists cairo-skia && echo 1 || echo 0)
+ifneq ($(SKIA),0)
+DEFINES+=-DHAVE_SKIA=1
+SOURCES+=skia.c
+REQUIRES+=cairo-skia
+else
+DEFINES+=-DHAVE_SKIA=0
+endif
+
 all: spiral-demo tiger-demo fish-demo flowers-demo gears-demo gradient-demo chart-demo waterfall-demo dragon-demo pythagoras-demo wave-demo sierpinski-demo maze-demo
 
 ifeq ($(shell pkg-config --exists poppler-glib && echo 1), 1)
diff --git a/chart-demo.c b/chart-demo.c
index a7c7b36..cad22f4 100644
--- a/chart-demo.c
+++ b/chart-demo.c
@@ -40,7 +40,7 @@ static void chart_init(struct chart *c,
 {
 	int n;
 
-	c->array = malloc(size);
+	c->array = (int8_t *)malloc(size);
 	c->y = y;
 	c->scale = scale;
 	c->size = size;
diff --git a/demo.c b/demo.c
index ed7cb5f..c50bf1e 100644
--- a/demo.c
+++ b/demo.c
@@ -145,6 +145,7 @@ struct device *device_open(int argc, char **argv)
 	AUTO,
 	XLIB,
 	XIMAGE,
+	SKIA,
 	XCB,
 	GLX,
 	COGL,
@@ -165,6 +166,8 @@ struct device *device_open(int argc, char **argv)
 	    backend = GLX;
 	} else if (strcmp (argv[n], "--cogl") == 0) {
 	    backend = COGL;
+	} else if (strcmp (argv[n], "--skia") == 0) {
+	    backend = SKIA;
 	}
     }
 
@@ -181,6 +184,8 @@ struct device *device_open(int argc, char **argv)
 	    device = cogl_open (argc, argv);
 	if (device == 0 && HAVE_XIMAGE)
 	    device = ximage_open (argc, argv);
+	if (device == 0 && HAVE_SKIA)
+	    device = skia_open (argc, argv);
     } else switch (backend) {
     case AUTO:
     case XLIB:
@@ -192,6 +197,9 @@ struct device *device_open(int argc, char **argv)
     case XIMAGE:
 	device = ximage_open (argc, argv);
 	break;
+    case SKIA:
+	device = skia_open (argc, argv);
+	break;
     case GLX:
 	device = glx_open (argc, argv);
 	break;
diff --git a/demo.h b/demo.h
index ff32058..17a2109 100644
--- a/demo.h
+++ b/demo.h
@@ -40,7 +40,8 @@ enum split {
 	SPLIT_TOP_RIGHT,
 	SPLIT_BOTTOM_LEFT,
 	SPLIT_BOTTOM_RIGHT,
-} device_get_split(int argc, char **argv);
+};
+enum split device_get_split(int argc, char **argv);
 
 cairo_antialias_t device_get_antialias(int argc, char **argv);
 const char *device_antialias_to_string(cairo_antialias_t antialias);
@@ -54,7 +55,8 @@ enum clip {
 	CLIP_BOX2,
 	CLIP_DIAMOND,
 	CLIP_CIRCLE,
-} device_get_clip(int argc, char **argv);
+};
+enum clip device_get_clip(int argc, char **argv);
 void device_apply_clip(struct device *device, cairo_t *cr, enum clip c);
 
 #if HAVE_COGL
@@ -93,6 +95,12 @@ struct device *drm_open (int argc, char **argv);
 static inline struct device *drm_open (int argc, char **argv) { return 0; }
 #endif
 
+#if HAVE_SKIA
+struct device *skia_open (int argc, char **argv);
+#else
+static inline struct device *skia_open (int argc, char **argv) { return 0; }
+#endif
+
 #if HAVE_GDK_PIXBUF
 #include <gdk-pixbuf/gdk-pixbuf.h>
 
diff --git a/fish-demo.c b/fish-demo.c
index 6082d47..8555166 100644
--- a/fish-demo.c
+++ b/fish-demo.c
@@ -84,7 +84,7 @@ static cairo_surface_t **create_strip(struct device *device)
 	fish_width = width;
 	fish_height = height;
 
-	strip = malloc(sizeof(cairo_surface_t*)*48);
+	strip = (cairo_surface_t **)malloc(sizeof(cairo_surface_t*)*48);
 	for (y = 0; y < 3; y++) {
 		for (x = 0; x < 16; x++) {
 			strip[y*16+x] =
@@ -205,11 +205,12 @@ int main (int argc, char **argv)
 		if (strncmp(argv[n], "--num-fish=", 11) == 0)
 			num_fish = atoi(argv[n]+11);
 		else if (strcmp(argv[n], "--reflection") == 0)
-			reflection = (void *)1;
+			reflection = (cairo_pattern_t *)1;
 		else if (strcmp(argv[n], "--solid-background") == 0)
 			solid_bg = 1;
 	}
 
+	x1 = -1;
 	if (solid_bg)
 		bg = solid_background();
 	else
@@ -217,9 +218,7 @@ int main (int argc, char **argv)
 	if (cairo_pattern_status(bg))
 		return 1;
 
-	if (reflection == NULL || x1 < 0) {
-		x1 = 0, x2 = device->width;
-	} else {
+	if (reflection != NULL && x1 >= 0) {
 		reflection = cairo_pattern_create_linear(0,0, device->width, 0);
 		cairo_pattern_add_color_stop_rgba(reflection, 0, 0, 0, 0, 0);
 		cairo_pattern_add_color_stop_rgba(reflection, x1/(double)device->width, 0, 0, 0, .75);
@@ -227,11 +226,12 @@ int main (int argc, char **argv)
 		cairo_pattern_add_color_stop_rgba(reflection, x2/(double)device->width, 0, 0, 0, 1);
 		cairo_pattern_add_color_stop_rgba(reflection, x2/(double)device->width, 0, 0, 0, .75);
 		cairo_pattern_add_color_stop_rgba(reflection, 1, 0, 0, 0, 0);
-	}
+	} else
+		x1 = 0, x2 = device->width;
 
 	strip = create_strip(device);
 
-	fish = malloc(sizeof(*fish)*num_fish);
+	fish = (struct fish *)malloc(sizeof(*fish)*num_fish);
 	for (n = 0; n < num_fish; n++)
 		fish_init(device, &fish[n], x1, x2);
 
diff --git a/maze-demo.c b/maze-demo.c
index e6b51b7..c6e7286 100644
--- a/maze-demo.c
+++ b/maze-demo.c
@@ -216,7 +216,7 @@ static void maze_create(void)
 	int i, h2 = 2 * h + 2, w2 = 2 * w + 2;
 	uint8_t **p;
 
-	p = calloc(sizeof(uint8_t*) * (h2 + 2) + w2 * h2 + 1, 1);
+	p = (uint8_t **)calloc(sizeof(uint8_t*) * (h2 + 2) + w2 * h2 + 1, 1);
 
 	p[1] = (uint8_t*)(p + h2 + 2) + 1;
 	each(i, 2, h2) p[i] = p[i-1] + w2;
diff --git a/skia.c b/skia.c
new file mode 100644
index 0000000..6efa0d8
--- /dev/null
+++ b/skia.c
@@ -0,0 +1,201 @@
+#include <cairo-xlib.h>
+#include <cairo-skia.h>
+
+#include "demo.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+
+#include <X11/extensions/XShm.h>
+#include <sys/ipc.h>
+#include <sys/shm.h>
+
+struct skia_device {
+    struct device base;
+    struct framebuffer fb;
+
+    Display *display;
+    Window drawable;
+
+    int stride;
+    Pixmap pixmap;
+    GC gc;
+    XShmSegmentInfo shm;
+};
+
+static void
+destroy (struct framebuffer *abstract_framebuffer)
+{
+}
+
+static cairo_bool_t
+_native_byte_order_lsb (void)
+{
+    int	x = 1;
+
+    return *((char *) &x) == 1;
+}
+
+static void
+show (struct framebuffer *fb)
+{
+    struct skia_device *device = (struct skia_device *) fb->device;
+
+    if (device->pixmap) {
+	XCopyArea (device->display, device->pixmap, device->drawable, device->gc,
+		   0, 0,
+		   device->base.width, device->base.height,
+		   0, 0);
+    } else {
+	XImage ximage;
+	int native_byte_order = _native_byte_order_lsb () ? LSBFirst : MSBFirst;
+
+	ximage.width = device->base.width;
+	ximage.height = device->base.height;
+	ximage.format = ZPixmap;
+	ximage.byte_order = native_byte_order;
+	ximage.bitmap_unit = 32;	/* always for libpixman */
+	ximage.bitmap_bit_order = native_byte_order;
+	ximage.bitmap_pad = 32;	/* always for libpixman */
+	ximage.depth = 24;
+	ximage.red_mask = 0xff;
+	ximage.green_mask = 0xff00;
+	ximage.blue_mask = 0xff000;
+	ximage.xoffset = 0;
+	ximage.bits_per_pixel = 32;
+	ximage.data = device->shm.shmaddr;
+	ximage.obdata = (char *) &device->shm;
+	ximage.bytes_per_line = device->stride;
+
+	XShmPutImage (device->display, device->drawable, device->gc, &ximage,
+		      0, 0, 0, 0, device->base.width, device->base.height,
+		      False);
+    }
+
+    XSync (device->display, True);
+}
+
+static struct framebuffer *
+get_fb (struct device *abstract_device)
+{
+    struct skia_device *device = (struct skia_device *) abstract_device;
+    return &device->fb;
+}
+
+struct device *
+skia_open (int argc, char **argv)
+{
+    struct skia_device *device;
+    Display *dpy;
+    Screen *scr;
+    int screen;
+    XSetWindowAttributes attr;
+    int major, minor, has_pixmap;
+    int x, y;
+    XGCValues gcv;
+
+    dpy = XOpenDisplay (NULL);
+    if (dpy == NULL)
+	return NULL;
+
+    if (! XShmQueryExtension (dpy)) {
+	XCloseDisplay (dpy);
+	return NULL;
+    }
+
+    device = (struct skia_device *) malloc (sizeof (struct skia_device));
+    device->base.name = "skia";
+    device->base.get_framebuffer = get_fb;
+    device->display = dpy;
+
+    screen = DefaultScreen (dpy);
+    scr = XScreenOfDisplay (dpy, screen);
+    device->base.width = WidthOfScreen (scr);
+    device->base.height = HeightOfScreen (scr);
+    device_get_size (argc, argv, &device->base.width, &device->base.height);
+    x = y = 0;
+    switch (device_get_split(argc, argv)) {
+    case SPLIT_NONE:
+	    break;
+    case SPLIT_LEFT:
+	    device->base.width /= 2;
+	    break;
+    case SPLIT_RIGHT:
+	    x = device->base.width /= 2;
+	    break;
+    case SPLIT_TOP:
+	    device->base.height /= 2;
+	    break;
+    case SPLIT_BOTTOM:
+	    y = device->base.height /= 2;
+	    break;
+
+    case SPLIT_BOTTOM_LEFT:
+	    device->base.width /= 2;
+	    y = device->base.height /= 2;
+	    break;
+    case SPLIT_BOTTOM_RIGHT:
+	    x = device->base.width /= 2;
+	    y = device->base.height /= 2;
+	    break;
+
+    case SPLIT_TOP_LEFT:
+	    device->base.width /= 2;
+	    device->base.height /= 2;
+	    break;
+    case SPLIT_TOP_RIGHT:
+	    x = device->base.width /= 2;
+	    device->base.height /= 2;
+	    break;
+    }
+
+    attr.override_redirect = True;
+    device->drawable = XCreateWindow (dpy, DefaultRootWindow (dpy),
+				      x, y,
+				      device->base.width, device->base.height, 0,
+				      DefaultDepth (dpy, screen),
+				      InputOutput,
+				      DefaultVisual (dpy, screen),
+				      CWOverrideRedirect, &attr);
+    XMapWindow (dpy, device->drawable);
+
+    device->stride = cairo_format_stride_for_width (CAIRO_FORMAT_RGB24, device->base.width);
+
+    device->shm.shmid = shmget(IPC_PRIVATE, device->stride * device->base.height, IPC_CREAT | 0777);
+    device->shm.shmaddr = (char *) shmat (device->shm.shmid, NULL, 0);
+    device->shm.readOnly = False;
+
+    if (!XShmAttach (dpy, &device->shm))
+	abort ();
+
+    device->base.scanout = cairo_skia_surface_create_for_data ((uint8_t *) device->shm.shmaddr,
+								CAIRO_FORMAT_RGB24,
+								device->base.width,
+								device->base.height,
+								device->stride);
+    XShmQueryVersion (dpy, &major, &minor, &has_pixmap);
+
+    if (has_pixmap) {
+	printf ("Using SHM Pixmap\n");
+	device->pixmap = XShmCreatePixmap (dpy,
+					   device->drawable,
+					   device->shm.shmaddr,
+					   &device->shm,
+					   device->base.width,
+					   device->base.height,
+					   24);
+    } else {
+	printf ("Using SHM PutImage\n");
+	device->pixmap = 0;
+    }
+
+    gcv.graphics_exposures = False;
+    device->gc = XCreateGC (dpy, device->drawable, GCGraphicsExposures, &gcv);
+
+    device->fb.device = &device->base;
+    device->fb.show = show;
+    device->fb.destroy = destroy;
+    device->fb.surface = device->base.scanout;
+
+    return &device->base;
+}
diff --git a/spinner-demo.c b/spinner-demo.c
index f737fe1..ea2921e 100644
--- a/spinner-demo.c
+++ b/spinner-demo.c
@@ -41,8 +41,7 @@ static int load_source(const char *filename, struct device *device)
 	if (!preload && !prescale) {
 		struct source *s;
 
-		s = realloc(sources,
-			    (num_sources+1)*sizeof(struct source));
+		s = (struct source *)realloc(sources, (num_sources+1)*sizeof(struct source));
 		if (s == NULL) {
 			cairo_surface_destroy(image);
 			return 0;
@@ -89,8 +88,7 @@ static int load_source(const char *filename, struct device *device)
 	if (status == CAIRO_STATUS_SUCCESS) {
 		struct source *s;
 
-		s = realloc(sources,
-			    (num_sources+1)*sizeof(struct source));
+		s = (struct source *)realloc(sources, (num_sources+1)*sizeof(struct source));
 		if (s) {
 			s[num_sources].surface =
 				cairo_surface_reference(surface);
diff --git a/ximage.c b/ximage.c
index 77456ee..9ff23ff 100644
--- a/ximage.c
+++ b/ximage.c
@@ -102,7 +102,7 @@ ximage_open (int argc, char **argv)
 	return NULL;
     }
 
-    device = malloc (sizeof (struct ximage_device));
+    device = (struct ximage_device *) malloc (sizeof (struct ximage_device));
     device->base.name = "ximage";
     device->base.get_framebuffer = get_fb;
     device->display = dpy;
@@ -161,7 +161,7 @@ ximage_open (int argc, char **argv)
     device->stride = cairo_format_stride_for_width (CAIRO_FORMAT_RGB24, device->base.width);
 
     device->shm.shmid = shmget(IPC_PRIVATE, device->stride * device->base.height, IPC_CREAT | 0777);
-    device->shm.shmaddr = shmat (device->shm.shmid, NULL, 0);
+    device->shm.shmaddr = (char *) shmat (device->shm.shmid, NULL, 0);
     device->shm.readOnly = False;
 
     if (!XShmAttach (dpy, &device->shm))