Factor out common cairo code, add blur function.

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);
+}