Factor out common cairo code, add blur function.
diff --git a/cairo-util.c b/cairo-util.c
new file mode 100644
index 0000000..4891f87
--- /dev/null
+++ b/cairo-util.c
@@ -0,0 +1,176 @@
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <i915_drm.h>
+#include <sys/ioctl.h>
+#include <math.h>
+#include <cairo.h>
+#include "cairo-util.h"
+
+struct buffer *
+buffer_create(int fd, int width, int height, int stride)
+{
+ struct buffer *buffer;
+ struct drm_i915_gem_create create;
+ struct drm_gem_flink flink;
+
+ buffer = malloc(sizeof *buffer);
+ buffer->width = width;
+ buffer->height = height;
+ buffer->stride = stride;
+
+ memset(&create, 0, sizeof(create));
+ create.size = height * stride;
+
+ if (ioctl(fd, DRM_IOCTL_I915_GEM_CREATE, &create) != 0) {
+ fprintf(stderr, "gem create failed: %m\n");
+ free(buffer);
+ return NULL;
+ }
+
+ flink.handle = create.handle;
+ if (ioctl(fd, DRM_IOCTL_GEM_FLINK, &flink) != 0) {
+ fprintf(stderr, "gem flink failed: %m\n");
+ free(buffer);
+ return 0;
+ }
+
+ buffer->handle = flink.handle;
+ buffer->name = flink.name;
+
+ return buffer;
+}
+
+int
+buffer_destroy(struct buffer *buffer, int fd)
+{
+ struct drm_gem_close close;
+
+ close.handle = buffer->handle;
+ if (ioctl(fd, DRM_IOCTL_GEM_CLOSE, &close) < 0) {
+ fprintf(stderr, "gem close failed: %m\n");
+ return -1;
+ }
+
+ free(buffer);
+
+ return 0;
+}
+
+int
+buffer_data(struct buffer *buffer, int fd, void *data)
+{
+ struct drm_i915_gem_pwrite pwrite;
+
+ pwrite.handle = buffer->handle;
+ pwrite.offset = 0;
+ pwrite.size = buffer->height * buffer->stride;
+ pwrite.data_ptr = (uint64_t) (uintptr_t) data;
+
+ if (ioctl(fd, DRM_IOCTL_I915_GEM_PWRITE, &pwrite) < 0) {
+ fprintf(stderr, "gem pwrite failed: %m\n");
+ return -1;
+ }
+
+ return 0;
+}
+
+struct buffer *
+buffer_create_from_cairo_surface(int fd, cairo_surface_t *surface)
+{
+ struct buffer *buffer;
+ int32_t width, height, stride;
+ void *data;
+
+ width = cairo_image_surface_get_width(surface);
+ height = cairo_image_surface_get_height(surface);
+ stride = cairo_image_surface_get_stride(surface);
+ data = cairo_image_surface_get_data(surface);
+
+ buffer = buffer_create(fd, width, height, stride);
+ if (buffer == NULL)
+ return NULL;
+
+ if (buffer_data(buffer, fd, data) < 0) {
+ buffer_destroy(buffer, fd);
+ return NULL;
+ }
+
+ return buffer;
+}
+
+void
+blur_surface(cairo_surface_t *surface)
+{
+ cairo_surface_t *tmp;
+ int32_t width, height, stride, x, y, z, w;
+ uint8_t *src, *dst;
+ uint32_t *s, *d, a, p;
+ int i, j, k, size = 23, half;
+ uint8_t kernel[100];
+ double f;
+
+ width = cairo_image_surface_get_width(surface);
+ height = cairo_image_surface_get_height(surface);
+ stride = cairo_image_surface_get_stride(surface);
+ src = cairo_image_surface_get_data(surface);
+
+ tmp = cairo_image_surface_create(CAIRO_FORMAT_RGB24, width, height);
+ dst = cairo_image_surface_get_data(tmp);
+
+ half = size / 2;
+ a = 0;
+ for (i = 0; i < size; i++) {
+ f = (i - half);
+ kernel[i] = exp(- f * f / 30.0) * 80;
+ a += kernel[i];
+ }
+
+ for (i = 0; i < height; i++) {
+ s = (uint32_t *) (src + i * stride);
+ d = (uint32_t *) (dst + i * stride);
+ for (j = 0; j < width; j++) {
+ x = 0;
+ y = 0;
+ z = 0;
+ w = 0;
+ for (k = 0; k < size; k++) {
+ if (j - half + k < 0 || j - half + k >= width)
+ continue;
+ p = s[j - half + k];
+
+ x += (p >> 24) * kernel[k];
+ y += ((p >> 16) & 0xff) * kernel[k];
+ z += ((p >> 8) & 0xff) * kernel[k];
+ w += (p & 0xff) * kernel[k];
+ }
+ d[j] = (x / a << 24) | (y / a << 16) | (z / a << 8) | w / a;
+ }
+ }
+
+ for (i = 0; i < height; i++) {
+ s = (uint32_t *) (dst + i * stride);
+ d = (uint32_t *) (src + i * stride);
+ for (j = 0; j < width; j++) {
+ x = 0;
+ y = 0;
+ z = 0;
+ w = 0;
+ for (k = 0; k < size; k++) {
+ if (i - half + k < 0 || i - half + k >= height)
+ continue;
+ s = (uint32_t *) (dst + (i - half + k) * stride);
+ p = s[j];
+
+ x += (p >> 24) * kernel[k];
+ y += ((p >> 16) & 0xff) * kernel[k];
+ z += ((p >> 8) & 0xff) * kernel[k];
+ w += (p & 0xff) * kernel[k];
+ }
+ d[j] = (x / a << 24) | (y / a << 16) | (z / a << 8) | w / a;
+ }
+ }
+
+ cairo_surface_destroy(tmp);
+}