[igt-dev] [PATCH i-g-t 03/12] fb: Add format conversion routine

[Maxime Ripard]

The chamelium format subtests will need to convert the reference pattern to
the format to be tested on the DRM device.

However, Cairo is very limited when it comes to format, and while pixman
has much more support for formats, it's still falling short compared to
what DRM exposes, especially on the YUV side.

In order to abstract this away, let's create a function that will convert a
igt_fb structure to another DRM format and return the converted igt_fb.

For now, we will use pixman to do the conversion, but we will use other
libraries or roll our own routines to convert to more exotic formats and
abstract it away from the users.

Signed-off-by: Maxime Ripard <maxime.ripard at bootlin.com>
---
 lib/igt_fb.c | 90 ++++++++++++++++++++++++++++++++++++++++++++++++-----
 lib/igt_fb.h |  2 +-
 2 files changed, 84 insertions(+), 8 deletions(-)

diff --git a/lib/igt_fb.c b/lib/igt_fb.c
index e0d543aa1aeb..1de6f9f6c275 100644
--- a/lib/igt_fb.c
+++ b/lib/igt_fb.c
@@ -28,6 +28,7 @@
 #include <stdio.h>
 #include <math.h>
 #include <inttypes.h>
+#include <pixman.h>
 
 #include "drmtest.h"
 #include "igt_fb.h"
@@ -54,24 +55,27 @@
  * functions to work with these pixel format codes.
  */
 
+#define PIXMAN_invalid	-1
+
 /* drm fourcc/cairo format maps */
-#define DF(did, cid, ...)	\
-	{ DRM_FORMAT_##did, CAIRO_FORMAT_##cid, # did, __VA_ARGS__ }
+#define DF(did, cid, pid, ...)					\
+	{ DRM_FORMAT_##did, CAIRO_FORMAT_##cid, PIXMAN_##pid, # did, __VA_ARGS__ }
 static struct format_desc_struct {
 	uint32_t drm_id;
 	cairo_format_t cairo_id;
+	pixman_format_code_t pixman_id;
 	const char *name;
 	int bpp;
 	int depth;
 	int planes;
 	int plane_bpp[4];
 } format_desc[] = {
-	DF(RGB565,	RGB16_565,	16, 16),
-	//DF(RGB888,	INVALID,	24, 24),
-	DF(XRGB8888,	RGB24,		32, 24),
-	DF(XRGB2101010,	RGB30,		32, 30),
-	DF(ARGB8888,	ARGB32,		32, 32),
-	DF(NV12,	RGB24,		32, -1, 2, {8, 16}),
+	DF(RGB565,	RGB16_565,	r5g6b5,		16, 16),
+	//DF(RGB888,	INVALID,	r8g8b8,		24, 24),
+	DF(XRGB8888,	RGB24,		x8r8g8b8,	32, 24),
+	DF(XRGB2101010,	RGB30,		x2r10g10b10,	32, 30),
+	DF(ARGB8888,	ARGB32,		a8r8g8b8,	32, 32),
+	DF(NV12,	RGB24,		invalid,	32, -1, 2, {8, 16}),
 };
 #undef DF
 
@@ -1123,6 +1127,18 @@ unsigned int igt_create_stereo_fb(int drm_fd, drmModeModeInfo *mode,
 	return fb_id;
 }
 
+static pixman_format_code_t drm_format_to_pixman(uint32_t drm_format)
+{
+	struct format_desc_struct *f;
+
+	for_each_format(f)
+		if (f->drm_id == drm_format)
+			return f->pixman_id;
+
+	igt_assert_f(0, "can't find a pixman format for %08x (%s)\n",
+		     drm_format, igt_format_str(drm_format));
+}
+
 static cairo_format_t drm_format_to_cairo(uint32_t drm_format)
 {
 	struct format_desc_struct *f;
@@ -1675,6 +1691,64 @@ void igt_remove_fb(int fd, struct igt_fb *fb)
 }
 
 /**
+ * igt_fb_convert:
+ * @dst: pointer to the #igt_fb structure that will store the conversion result
+ * @src: pointer to the #igt_fb structure that stores the frame we convert
+ * @dst_fourcc: DRM format specifier to convert to
+ *
+ * This will convert a given @src content to the @dst_fourcc format,
+ * storing the result in the @dst fb, allocating the @dst fb
+ * underlying buffer.
+ *
+ * Once done with @dst, the caller will have to call igt_remove_fb()
+ * on it to free the associated resources.
+ *
+ * Returns:
+ * The kms id of the created framebuffer.
+ */
+unsigned int igt_fb_convert(struct igt_fb *dst, struct igt_fb *src,
+			    uint32_t dst_fourcc)
+{
+	pixman_format_code_t src_pixman = drm_format_to_pixman(src->drm_format);
+	pixman_format_code_t dst_pixman = drm_format_to_pixman(dst_fourcc);
+	pixman_image_t *dst_image, *src_image;
+	void *dst_ptr, *src_ptr;
+	int fb_id;
+
+	igt_assert(src_pixman != PIXMAN_invalid);
+	igt_assert(dst_pixman != PIXMAN_invalid);
+
+	fb_id = igt_create_fb(src->fd, src->width, src->height,
+			      dst_fourcc, LOCAL_DRM_FORMAT_MOD_NONE, dst);
+	igt_assert(fb_id > 0);
+
+	src_ptr = igt_fb_get_buffer(src->fd, src);
+	igt_assert(src_ptr);
+
+	dst_ptr = igt_fb_get_buffer(dst->fd, dst);
+	igt_assert(dst_ptr);
+
+	src_image = pixman_image_create_bits(src_pixman,
+					     src->width, src->height,
+					     src_ptr, src->stride);
+	igt_assert(src_image);
+
+	dst_image = pixman_image_create_bits(dst_pixman,
+					     dst->width, dst->height,
+					     dst_ptr, dst->stride);
+	igt_assert(dst_image);
+
+	pixman_image_composite(PIXMAN_OP_SRC, src_image, NULL, dst_image,
+			       0, 0, 0, 0, 0, 0, dst->width, dst->height);
+	pixman_image_unref(dst_image);
+	pixman_image_unref(src_image);
+	igt_fb_put_buffer(dst, dst_ptr);
+	igt_fb_put_buffer(src, src_ptr);
+
+	return fb_id;
+}
+
+/**
  * igt_bpp_depth_to_drm_format:
  * @bpp: desired bits per pixel
  * @depth: desired depth
diff --git a/lib/igt_fb.h b/lib/igt_fb.h
index 631fe5db7318..09df52e34992 100644
--- a/lib/igt_fb.h
+++ b/lib/igt_fb.h
@@ -126,6 +126,8 @@ unsigned int igt_create_image_fb(int drm_fd,  int width, int height,
 				 struct igt_fb *fb /* out */);
 unsigned int igt_create_stereo_fb(int drm_fd, drmModeModeInfo *mode,
 				  uint32_t format, uint64_t tiling);
+unsigned int igt_fb_convert(struct igt_fb *dst, struct igt_fb *src,
+			    uint32_t dst_fourcc);
 void igt_remove_fb(int fd, struct igt_fb *fb);
 int igt_dirty_fb(int fd, struct igt_fb *fb);
 void *igt_fb_get_buffer(int fd, struct igt_fb *fb);
-- 
git-series 0.9.1