[PATCH libdrm v2 06/10] util: Add SMPTE pattern support for C4 format

[Geert Uytterhoeven]

Add support for drawing the SMPTE pattern in a buffer using the C4
indexed format.

Signed-off-by: Geert Uytterhoeven <geert at linux-m68k.org>
---
v2:
  - Use new smpte_top[],
  - Split off changes to tests/util/pattern.c.
---
 tests/util/pattern.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/tests/util/pattern.c b/tests/util/pattern.c
index 5a648b468e524fbb..8ed5f8dd1a6282f9 100644
--- a/tests/util/pattern.c
+++ b/tests/util/pattern.c
@@ -668,6 +668,46 @@ static unsigned int smpte_bottom[8] = {
 	SMPTE_COLOR_BLACK,
 };
 
+static void write_pixel_4(uint8_t *mem, unsigned int x, unsigned int pixel)
+{
+	if (x & 1)
+		mem[x / 2] = (mem[x / 2] & 0xf0) | (pixel & 0x0f);
+	else
+		mem[x / 2] = (mem[x / 2] & 0x0f) | (pixel << 4);
+}
+
+static void fill_smpte_c4(void *mem, unsigned int width, unsigned int height,
+			  unsigned int stride)
+{
+	unsigned int x;
+	unsigned int y;
+
+	for (y = 0; y < height * 6 / 9; ++y) {
+		for (x = 0; x < width; ++x)
+			write_pixel_4(mem, x, smpte_top[x * 7 / width]);
+		mem += stride;
+	}
+
+	for (; y < height * 7 / 9; ++y) {
+		for (x = 0; x < width; ++x)
+			write_pixel_4(mem, x, smpte_middle[x * 7 / width]);
+		mem += stride;
+	}
+
+	for (; y < height; ++y) {
+		for (x = 0; x < width * 5 / 7; ++x)
+			write_pixel_4(mem, x,
+				      smpte_bottom[x * 4 / (width * 5 / 7)]);
+		for (; x < width * 6 / 7; ++x)
+			write_pixel_4(mem, x,
+				      smpte_bottom[(x - width * 5 / 7) * 3 /
+						   (width / 7) + 4]);
+		for (; x < width; ++x)
+			write_pixel_4(mem, x, smpte_bottom[7]);
+		mem += stride;
+	}
+}
+
 static void fill_smpte_c8(void *mem, unsigned int width, unsigned int height,
 			  unsigned int stride)
 {
@@ -726,6 +766,8 @@ static void fill_smpte(const struct util_format_info *info, void *planes[3],
 	unsigned char *u, *v;
 
 	switch (info->format) {
+	case DRM_FORMAT_C4:
+		return fill_smpte_c4(planes[0], width, height, stride);
 	case DRM_FORMAT_C8:
 		return fill_smpte_c8(planes[0], width, height, stride);
 	case DRM_FORMAT_UYVY:
-- 
2.25.1