drm: Add backends for i915 and i965.

As proof-of-principle add the nearly working demonstrations of using DRM
to render directly with the GPU bypassing both RENDER and GL for
performance whilst preserving high quality rendering.

The basis behind developing these chip specific backends is that this is
the idealised interface that we desire for this chips, and so a target
for cairo-gl as we continue to develop both it and our GL stack.

Note that this backends do not yet fully pass the test suite, so only
use if you are brave and willing to help develop them further.

boilerplate/cairo-boilerplate-drm.c

@@ -45,7 +45,7 @@ _cairo_boilerplate_drm_create_surface (const char		 *name,
 				       int			  id,
 				       void			**closure)
 {
-    cairo_drm_device_t *device;
+    cairo_device_t *device;
 
     device = cairo_drm_device_default ();
     if (device == NULL)

src/Makefile.sources

@@ -310,12 +310,29 @@ cairo_directfb_sources = cairo-directfb-surface.c
 cairo_drm_headers = cairo-drm.h
 cairo_drm_private = drm/cairo-drm-private.h \
 		    drm/cairo-drm-intel-private.h \
+		    drm/cairo-drm-i915-private.h \
+		    drm/cairo-drm-i965-private.h \
+		    drm/cairo-drm-intel-brw-defines.h \
+		    drm/cairo-drm-intel-brw-structs.h \
+		    drm/cairo-drm-intel-brw-eu.h \
 		    drm/cairo-drm-radeon-private.h
 cairo_drm_sources = drm/cairo-drm.c \
 		    drm/cairo-drm-bo.c \
 		    drm/cairo-drm-surface.c \
 		    drm/cairo-drm-intel.c \
+		    drm/cairo-drm-intel-debug.c \
 		    drm/cairo-drm-intel-surface.c \
+		    drm/cairo-drm-i915-surface.c \
+		    drm/cairo-drm-i915-glyphs.c \
+		    drm/cairo-drm-i915-shader.c \
+		    drm/cairo-drm-i915-spans.c \
+		    drm/cairo-drm-i965-surface.c \
+		    drm/cairo-drm-i965-glyphs.c \
+		    drm/cairo-drm-i965-shader.c \
+		    drm/cairo-drm-i965-spans.c \
+		    drm/cairo-drm-intel-brw-eu.c \
+		    drm/cairo-drm-intel-brw-eu-emit.c \
+		    drm/cairo-drm-intel-brw-eu-util.c \
 		    drm/cairo-drm-radeon.c \
 		    drm/cairo-drm-radeon-surface.c
 cairo_gallium_sources = drm/cairo-drm-gallium-surface.c

src/cairo-drm.h

@@ -39,56 +39,41 @@
 
 CAIRO_BEGIN_DECLS
 
-typedef struct _cairo_drm_device cairo_drm_device_t;
-
 struct udev_device;
 
-cairo_public cairo_drm_device_t *
+cairo_public cairo_device_t *
 cairo_drm_device_get (struct udev_device *device);
 
-cairo_public cairo_drm_device_t *
+cairo_public cairo_device_t *
 cairo_drm_device_get_for_fd (int fd);
 
-cairo_public cairo_drm_device_t *
+cairo_public cairo_device_t *
 cairo_drm_device_default (void);
 
-cairo_public cairo_drm_device_t *
-cairo_drm_device_reference (cairo_drm_device_t *device);
-
-cairo_public cairo_status_t
-cairo_drm_device_status (cairo_drm_device_t *device);
-
 cairo_public int
-cairo_drm_device_get_fd (cairo_drm_device_t *device);
+cairo_drm_device_get_fd (cairo_device_t *device);
 
 cairo_public void
-cairo_drm_device_throttle (cairo_drm_device_t *device);
-
-cairo_public void
-cairo_drm_device_destroy (cairo_drm_device_t *device);
-
+cairo_drm_device_throttle (cairo_device_t *device);
 
 cairo_public cairo_surface_t *
-cairo_drm_surface_create (cairo_drm_device_t *device,
+cairo_drm_surface_create (cairo_device_t *device,
 			  cairo_content_t content,
 			  int width, int height);
 
 cairo_public cairo_surface_t *
-cairo_drm_surface_create_for_name (cairo_drm_device_t *device,
+cairo_drm_surface_create_for_name (cairo_device_t *device,
 				   unsigned int name,
 	                           cairo_format_t format,
 				   int width, int height, int stride);
 
 cairo_public cairo_surface_t *
-cairo_drm_surface_create_from_cacheable_image (cairo_drm_device_t *device,
+cairo_drm_surface_create_from_cacheable_image (cairo_device_t *device,
 	                                       cairo_surface_t *surface);
 
 cairo_public cairo_status_t
 cairo_drm_surface_enable_scan_out (cairo_surface_t *surface);
 
-cairo_public cairo_drm_device_t *
-cairo_drm_surface_get_device (cairo_surface_t *abstract_surface);
-
 cairo_public unsigned int
 cairo_drm_surface_get_handle (cairo_surface_t *surface);
 

src/cairo-misc.c

@@ -674,6 +674,63 @@ _cairo_lround (double d)
 #undef LSW
 }
 
+/* Convert a 32-bit IEEE single precision floating point number to a
+ * 'half' representation (s10.5)
+ */
+uint16_t
+_cairo_half_from_float (float f)
+{
+    union {
+	uint32_t ui;
+	float f;
+    } u;
+    int s, e, m;
+
+    u.f = f;
+    s =  (u.ui >> 16) & 0x00008000;
+    e = ((u.ui >> 23) & 0x000000ff) - (127 - 15);
+    m =   u.ui        & 0x007fffff;
+    if (e <= 0) {
+	if (e < -10) {
+	    /* underflow */
+	    return 0;
+	}
+
+	m = (m | 0x00800000) >> (1 - e);
+
+	/* round to nearest, round 0.5 up. */
+	if (m &  0x00001000)
+	    m += 0x00002000;
+	return s | (m >> 13);
+    } else if (e == 0xff - (127 - 15)) {
+	if (m == 0) {
+	    /* infinity */
+	    return s | 0x7c00;
+	} else {
+	    /* nan */
+	    m >>= 13;
+	    return s | 0x7c00 | m | (m == 0);
+	}
+    } else {
+	/* round to nearest, round 0.5 up. */
+	if (m &  0x00001000) {
+	    m += 0x00002000;
+
+	    if (m & 0x00800000) {
+		m =  0;
+		e += 1;
+	    }
+	}
+
+	if (e > 30) {
+	    /* overflow -> infinity */
+	    return s | 0x7c00;
+	}
+
+	return s | (e << 10) | (m >> 13);
+    }
+}
+
 
 #ifdef _WIN32
 

src/cairoint.h

@@ -949,6 +949,8 @@ _cairo_round (double r)
 
 cairo_private int
 _cairo_lround (double d) cairo_const;
+cairo_private uint16_t
+_cairo_half_from_float (float f) cairo_const;
 
 /* cairo-gstate.c */
 cairo_private cairo_status_t

src/drm/cairo-drm-bo.c

@@ -31,11 +31,14 @@
 
 #include "cairo-drm-private.h"
 #include "cairo-drm-ioctl-private.h"
+
 #include "cairo-error-private.h"
 
 #include <sys/ioctl.h>
 #include <errno.h>
 
+#define ERR_DEBUG(x) x
+
 struct drm_gem_close {
 	/** Handle of the object to be closed. */
 	uint32_t handle;
@@ -79,8 +82,11 @@ _cairo_drm_bo_open_for_name (const cairo_drm_device_t *dev,
     do {
 	ret = ioctl (dev->fd, DRM_IOCTL_GEM_OPEN, &open);
     } while (ret == -1 && errno == EINTR);
-    if (ret == -1)
+    if (ret == -1) {
+	ERR_DEBUG((fprintf (stderr, "Failed to open bo for name %d: %s\n",
+			    name, strerror (errno))));
 	return _cairo_error (CAIRO_STATUS_NO_MEMORY);
+    }
 
     bo->name = name;
     bo->size = open.size;
@@ -99,8 +105,11 @@ _cairo_drm_bo_flink (const cairo_drm_device_t *dev,
     memset (&flink, 0, sizeof (flink));
     flink.handle = bo->handle;
     ret = ioctl (dev->fd, DRM_IOCTL_GEM_FLINK, &flink);
-    if (ret == -1)
+    if (ret == -1) {
+	ERR_DEBUG((fprintf (stderr, "Failed to flink bo: %s\n",
+			    strerror (errno))));
 	return _cairo_error (CAIRO_STATUS_NO_MEMORY);
+    }
 
     bo->name = flink.name;
 

src/drm/cairo-drm-gallium-surface.c

@@ -444,7 +444,6 @@ gallium_surface_create_internal (gallium_device_t *device,
 
     _cairo_surface_init (&surface->base.base,
 			 &gallium_surface_backend,
-			 NULL, /* device */
 			 content);
     _cairo_drm_surface_init (&surface->base, &device->base);
 
@@ -551,7 +550,6 @@ gallium_surface_create_for_name (cairo_drm_device_t *base_dev,
     content = _cairo_content_from_format (format);
     _cairo_surface_init (&surface->base.base,
 			 &gallium_surface_backend,
-			 NULL, /* device */
 			 content);
     _cairo_drm_surface_init (&surface->base, base_dev);
 
@@ -659,6 +657,7 @@ _cairo_drm_gallium_device_create (int fd, dev_t dev, int vendor_id, int chip_id)
     device->base.surface.enable_scan_out = NULL;
     device->base.surface.flink = gallium_surface_flink;
 
+    device->base.device.flush = NULL;
     device->base.device.throttle = NULL;
     device->base.device.destroy = gallium_device_destroy;