tests/util/pattern.c

/*
 * Copyright 2008 Tungsten Graphics
 *   Jakob Bornecrantz <jakob@tungstengraphics.com>
 * Copyright 2008 Intel Corporation
 *   Jesse Barnes <jesse.barnes@intel.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <drm_fourcc.h>

#if HAVE_CAIRO
#include <cairo.h>
#include <math.h>
#endif

#include "common.h"
#include "format.h"
#include "pattern.h"

struct color_rgb24 {
	unsigned int value:24;
} __attribute__((__packed__));

struct color_yuv {
	unsigned char y;
	unsigned char u;
	unsigned char v;
};

#define MAKE_YUV_601_Y(r, g, b) \
	((( 66 * (r) + 129 * (g) +  25 * (b) + 128) >> 8) + 16)
#define MAKE_YUV_601_U(r, g, b) \
	(((-38 * (r) -  74 * (g) + 112 * (b) + 128) >> 8) + 128)
#define MAKE_YUV_601_V(r, g, b) \
	(((112 * (r) -  94 * (g) -  18 * (b) + 128) >> 8) + 128)

#define MAKE_YUV_601(r, g, b) \
	{ .y = MAKE_YUV_601_Y(r, g, b), \
	  .u = MAKE_YUV_601_U(r, g, b), \
	  .v = MAKE_YUV_601_V(r, g, b) }

/* This function takes 8-bit color values */
static inline uint32_t shiftcolor8(const struct util_color_component *comp,
				  uint32_t value)
{
	value &= 0xff;
	/* Fill the low bits with the high bits. */
	value = (value << 8) | value;
	/* Shift down to remove unwanted low bits */
	value = value >> (16 - comp->length);
	/* Shift back up to where the value should be */
	return value << comp->offset;
}

/* This function takes 10-bit color values */
static inline uint32_t shiftcolor10(const struct util_color_component *comp,
				    uint32_t value)
{
	value &= 0x3ff;
	/* Fill the low bits with the high bits. */
	value = (value << 6) | (value >> 4);
	/* Shift down to remove unwanted low bits */
	value = value >> (16 - comp->length);
	/* Shift back up to where the value should be */
	return value << comp->offset;
}

/* This function takes 16-bit color values */
static inline uint64_t shiftcolor16(const struct util_color_component *comp,
				    uint64_t value)
{
	value &= 0xffff;
	/* Shift down to remove unwanted low bits */
	value = value >> (16 - comp->length);
	/* Shift back up to where the value should be */
	return value << comp->offset;
}

#define MAKE_RGBA10(rgb, r, g, b, a) \
	(shiftcolor10(&(rgb)->red, (r)) | \
	 shiftcolor10(&(rgb)->green, (g)) | \
	 shiftcolor10(&(rgb)->blue, (b)) | \
	 shiftcolor10(&(rgb)->alpha, (a)))

#define MAKE_RGBA(rgb, r, g, b, a) \
	(shiftcolor8(&(rgb)->red, (r)) | \
	 shiftcolor8(&(rgb)->green, (g)) | \
	 shiftcolor8(&(rgb)->blue, (b)) | \
	 shiftcolor8(&(rgb)->alpha, (a)))

#define MAKE_RGB24(rgb, r, g, b) \
	{ .value = MAKE_RGBA(rgb, r, g, b, 0) }


/**
  * Takes a uint16_t, divides by 65536, converts the infinite-precision
  * result to fp16 with round-to-zero.
  *
  * Copied from mesa:src/util/half_float.c
  */
static uint16_t uint16_div_64k_to_half(uint16_t v)
{
	/* Zero or subnormal. Set the mantissa to (v << 8) and return. */
	if (v < 4)
		return v << 8;

	/* Count the leading 0s in the uint16_t */
	int n = __builtin_clz(v) - 16;

	/* Shift the mantissa up so bit 16 is the hidden 1 bit,
	 * mask it off, then shift back down to 10 bits
	 */
	int m = ( ((uint32_t)v << (n + 1)) & 0xffff ) >> 6;

	/*  (0{n} 1 X{15-n}) * 2^-16
	 * = 1.X * 2^(15-n-16)
	 * = 1.X * 2^(14-n - 15)
	 * which is the FP16 form with e = 14 - n
	 */
	int e = 14 - n;

	return (e << 10) | m;
}

#define MAKE_RGBA8FP16(rgb, r, g, b, a) \
	(shiftcolor16(&(rgb)->red, uint16_div_64k_to_half((r) << 8)) | \
	 shiftcolor16(&(rgb)->green, uint16_div_64k_to_half((g) << 8)) | \
	 shiftcolor16(&(rgb)->blue, uint16_div_64k_to_half((b) << 8)) | \
	 shiftcolor16(&(rgb)->alpha, uint16_div_64k_to_half((a) << 8)))

#define MAKE_RGBA10FP16(rgb, r, g, b, a) \
	(shiftcolor16(&(rgb)->red, uint16_div_64k_to_half((r) << 6)) | \
	 shiftcolor16(&(rgb)->green, uint16_div_64k_to_half((g) << 6)) | \
	 shiftcolor16(&(rgb)->blue, uint16_div_64k_to_half((b) << 6)) | \
	 shiftcolor16(&(rgb)->alpha, uint16_div_64k_to_half((a) << 6)))

static void fill_smpte_yuv_planar(const struct util_yuv_info *yuv,
				  unsigned char *y_mem, unsigned char *u_mem,
				  unsigned char *v_mem, unsigned int width,
				  unsigned int height, unsigned int stride)
{
	const struct color_yuv colors_top[] = {
		MAKE_YUV_601(191, 192, 192),	/* grey */
		MAKE_YUV_601(192, 192, 0),	/* yellow */
		MAKE_YUV_601(0, 192, 192),	/* cyan */
		MAKE_YUV_601(0, 192, 0),	/* green */
		MAKE_YUV_601(192, 0, 192),	/* magenta */
		MAKE_YUV_601(192, 0, 0),	/* red */
		MAKE_YUV_601(0, 0, 192),	/* blue */
	};
	const struct color_yuv colors_middle[] = {
		MAKE_YUV_601(0, 0, 192),	/* blue */
		MAKE_YUV_601(19, 19, 19),	/* black */
		MAKE_YUV_601(192, 0, 192),	/* magenta */
		MAKE_YUV_601(19, 19, 19),	/* black */
		MAKE_YUV_601(0, 192, 192),	/* cyan */
		MAKE_YUV_601(19, 19, 19),	/* black */
		MAKE_YUV_601(192, 192, 192),	/* grey */
	};
	const struct color_yuv colors_bottom[] = {
		MAKE_YUV_601(0, 33, 76),	/* in-phase */
		MAKE_YUV_601(255, 255, 255),	/* super white */
		MAKE_YUV_601(50, 0, 106),	/* quadrature */
		MAKE_YUV_601(19, 19, 19),	/* black */
		MAKE_YUV_601(9, 9, 9),		/* 3.5% */
		MAKE_YUV_601(19, 19, 19),	/* 7.5% */
		MAKE_YUV_601(29, 29, 29),	/* 11.5% */
		MAKE_YUV_601(19, 19, 19),	/* black */
	};
	unsigned int cs = yuv->chroma_stride;
	unsigned int xsub = yuv->xsub;
	unsigned int ysub = yuv->ysub;
	unsigned int x;
	unsigned int y;

	/* Luma */
	for (y = 0; y < height * 6 / 9; ++y) {
		for (x = 0; x < width; ++x)
			y_mem[x] = colors_top[x * 7 / width].y;
		y_mem += stride;
	}

	for (; y < height * 7 / 9; ++y) {
		for (x = 0; x < width; ++x)
			y_mem[x] = colors_middle[x * 7 / width].y;
		y_mem += stride;
	}

	for (; y < height; ++y) {
		for (x = 0; x < width * 5 / 7; ++x)
			y_mem[x] = colors_bottom[x * 4 / (width * 5 / 7)].y;
		for (; x < width * 6 / 7; ++x)
			y_mem[x] = colors_bottom[(x - width * 5 / 7) * 3
						 / (width / 7) + 4].y;
		for (; x < width; ++x)
			y_mem[x] = colors_bottom[7].y;
		y_mem += stride;
	}

	/* Chroma */
	for (y = 0; y < height / ysub * 6 / 9; ++y) {
		for (x = 0; x < width; x += xsub) {
			u_mem[x*cs/xsub] = colors_top[x * 7 / width].u;
			v_mem[x*cs/xsub] = colors_top[x * 7 / width].v;
		}
		u_mem += stride * cs / xsub;
		v_mem += stride * cs / xsub;
	}

	for (; y < height / ysub * 7 / 9; ++y) {
		for (x = 0; x < width; x += xsub) {
			u_mem[x*cs/xsub] = colors_middle[x * 7 / width].u;
			v_mem[x*cs/xsub] = colors_middle[x * 7 / width].v;
		}
		u_mem += stride * cs / xsub;
		v_mem += stride * cs / xsub;
	}

	for (; y < height / ysub; ++y) {
		for (x = 0; x < width * 5 / 7; x += xsub) {
			u_mem[x*cs/xsub] =
				colors_bottom[x * 4 / (width * 5 / 7)].u;
			v_mem[x*cs/xsub] =
				colors_bottom[x * 4 / (width * 5 / 7)].v;
		}
		for (; x < width * 6 / 7; x += xsub) {
			u_mem[x*cs/xsub] = colors_bottom[(x - width * 5 / 7) *
							 3 / (width / 7) + 4].u;
			v_mem[x*cs/xsub] = colors_bottom[(x - width * 5 / 7) *
							 3 / (width / 7) + 4].v;
		}
		for (; x < width; x += xsub) {
			u_mem[x*cs/xsub] = colors_bottom[7].u;
			v_mem[x*cs/xsub] = colors_bottom[7].v;
		}
		u_mem += stride * cs / xsub;
		v_mem += stride * cs / xsub;
	}
}

static void fill_smpte_yuv_packed(const struct util_yuv_info *yuv, void *mem,
				  unsigned int width, unsigned int height,
				  unsigned int stride)
{
	const struct color_yuv colors_top[] = {
		MAKE_YUV_601(191, 192, 192),	/* grey */
		MAKE_YUV_601(192, 192, 0),	/* yellow */
		MAKE_YUV_601(0, 192, 192),	/* cyan */
		MAKE_YUV_601(0, 192, 0),	/* green */
		MAKE_YUV_601(192, 0, 192),	/* magenta */
		MAKE_YUV_601(192, 0, 0),	/* red */
		MAKE_YUV_601(0, 0, 192),	/* blue */
	};
	const struct color_yuv colors_middle[] = {
		MAKE_YUV_601(0, 0, 192),	/* blue */
		MAKE_YUV_601(19, 19, 19),	/* black */
		MAKE_YUV_601(192, 0, 192),	/* magenta */
		MAKE_YUV_601(19, 19, 19),	/* black */
		MAKE_YUV_601(0, 192, 192),	/* cyan */
		MAKE_YUV_601(19, 19, 19),	/* black */
		MAKE_YUV_601(192, 192, 192),	/* grey */
	};
	const struct color_yuv colors_bottom[] = {
		MAKE_YUV_601(0, 33, 76),	/* in-phase */
		MAKE_YUV_601(255, 255, 255),	/* super white */
		MAKE_YUV_601(50, 0, 106),	/* quadrature */
		MAKE_YUV_601(19, 19, 19),	/* black */
		MAKE_YUV_601(9, 9, 9),		/* 3.5% */
		MAKE_YUV_601(19, 19, 19),	/* 7.5% */
		MAKE_YUV_601(29, 29, 29),	/* 11.5% */
		MAKE_YUV_601(19, 19, 19),	/* black */
	};
	unsigned char *y_mem = (yuv->order & YUV_YC) ? mem : mem + 1;
	unsigned char *c_mem = (yuv->order & YUV_CY) ? mem : mem + 1;
	unsigned int u = (yuv->order & YUV_YCrCb) ? 2 : 0;
	unsigned int v = (yuv->order & YUV_YCbCr) ? 2 : 0;
	unsigned int x;
	unsigned int y;

	/* Luma */
	for (y = 0; y < height * 6 / 9; ++y) {
		for (x = 0; x < width; ++x)
			y_mem[2*x] = colors_top[x * 7 / width].y;
		y_mem += stride;
	}

	for (; y < height * 7 / 9; ++y) {
		for (x = 0; x < width; ++x)
			y_mem[2*x] = colors_middle[x * 7 / width].y;
		y_mem += stride;
	}

	for (; y < height; ++y) {
		for (x = 0; x < width * 5 / 7; ++x)
			y_mem[2*x] = colors_bottom[x * 4 / (width * 5 / 7)].y;
		for (; x < width * 6 / 7; ++x)
			y_mem[2*x] = colors_bottom[(x - width * 5 / 7) * 3
						   / (width / 7) + 4].y;
		for (; x < width; ++x)
			y_mem[2*x] = colors_bottom[7].y;
		y_mem += stride;
	}

	/* Chroma */
	for (y = 0; y < height * 6 / 9; ++y) {
		for (x = 0; x < width; x += 2) {
			c_mem[2*x+u] = colors_top[x * 7 / width].u;
			c_mem[2*x+v] = colors_top[x * 7 / width].v;
		}
		c_mem += stride;
	}

	for (; y < height * 7 / 9; ++y) {
		for (x = 0; x < width; x += 2) {
			c_mem[2*x+u] = colors_middle[x * 7 / width].u;
			c_mem[2*x+v] = colors_middle[x * 7 / width].v;
		}
		c_mem += stride;
	}

	for (; y < height; ++y) {
		for (x = 0; x < width * 5 / 7; x += 2) {
			c_mem[2*x+u] = colors_bottom[x * 4 / (width * 5 / 7)].u;
			c_mem[2*x+v] = colors_bottom[x * 4 / (width * 5 / 7)].v;
		}
		for (; x < width * 6 / 7; x += 2) {
			c_mem[2*x+u] = colors_bottom[(x - width * 5 / 7) *
						     3 / (width / 7) + 4].u;
			c_mem[2*x+v] = colors_bottom[(x - width * 5 / 7) *
						     3 / (width / 7) + 4].v;
		}
		for (; x < width; x += 2) {
			c_mem[2*x+u] = colors_bottom[7].u;
			c_mem[2*x+v] = colors_bottom[7].v;
		}
		c_mem += stride;
	}
}

static void fill_smpte_rgb16(const struct util_rgb_info *rgb, void *mem,
			     unsigned int width, unsigned int height,
			     unsigned int stride)
{
	const uint16_t colors_top[] = {
		MAKE_RGBA(rgb, 192, 192, 192, 255),	/* grey */
		MAKE_RGBA(rgb, 192, 192, 0, 255),	/* yellow */
		MAKE_RGBA(rgb, 0, 192, 192, 255),	/* cyan */
		MAKE_RGBA(rgb, 0, 192, 0, 255),		/* green */
		MAKE_RGBA(rgb, 192, 0, 192, 255),	/* magenta */
		MAKE_RGBA(rgb, 192, 0, 0, 255),		/* red */
		MAKE_RGBA(rgb, 0, 0, 192, 255),		/* blue */
	};
	const uint16_t colors_middle[] = {
		MAKE_RGBA(rgb, 0, 0, 192, 127),		/* blue */
		MAKE_RGBA(rgb, 19, 19, 19, 127),	/* black */
		MAKE_RGBA(rgb, 192, 0, 192, 127),	/* magenta */
		MAKE_RGBA(rgb, 19, 19, 19, 127),	/* black */
		MAKE_RGBA(rgb, 0, 192, 192, 127),	/* cyan */
		MAKE_RGBA(rgb, 19, 19, 19, 127),	/* black */
		MAKE_RGBA(rgb, 192, 192, 192, 127),	/* grey */
	};
	const uint16_t colors_bottom[] = {
		MAKE_RGBA(rgb, 0, 33, 76, 255),		/* in-phase */
		MAKE_RGBA(rgb, 255, 255, 255, 255),	/* super white */
		MAKE_RGBA(rgb, 50, 0, 106, 255),	/* quadrature */
		MAKE_RGBA(rgb, 19, 19, 19, 255),	/* black */
		MAKE_RGBA(rgb, 9, 9, 9, 255),		/* 3.5% */
		MAKE_RGBA(rgb, 19, 19, 19, 255),	/* 7.5% */
		MAKE_RGBA(rgb, 29, 29, 29, 255),	/* 11.5% */
		MAKE_RGBA(rgb, 19, 19, 19, 255),	/* black */
	};
	unsigned int x;
	unsigned int y;

	for (y = 0; y < height * 6 / 9; ++y) {
		for (x = 0; x < width; ++x)
			((uint16_t *)mem)[x] = colors_top[x * 7 / width];
		mem += stride;
	}

	for (; y < height * 7 / 9; ++y) {
		for (x = 0; x < width; ++x)
			((uint16_t *)mem)[x] = colors_middle[x * 7 / width];
		mem += stride;
	}

	for (; y < height; ++y) {
		for (x = 0; x < width * 5 / 7; ++x)
			((uint16_t *)mem)[x] =
				colors_bottom[x * 4 / (width * 5 / 7)];
		for (; x < width * 6 / 7; ++x)
			((uint16_t *)mem)[x] =
				colors_bottom[(x - width * 5 / 7) * 3
					      / (width / 7) + 4];
		for (; x < width; ++x)
			((uint16_t *)mem)[x] = colors_bottom[7];
		mem += stride;
	}
}

static void fill_smpte_rgb24(const struct util_rgb_info *rgb, void *mem,
			     unsigned int width, unsigned int height,
			     unsigned int stride)
{
	const struct color_rgb24 colors_top[] = {
		MAKE_RGB24(rgb, 192, 192, 192),	/* grey */
		MAKE_RGB24(rgb, 192, 192, 0),	/* yellow */
		MAKE_RGB24(rgb, 0, 192, 192),	/* cyan */
		MAKE_RGB24(rgb, 0, 192, 0),	/* green */
		MAKE_RGB24(rgb, 192, 0, 192),	/* magenta */
		MAKE_RGB24(rgb, 192, 0, 0),	/* red */
		MAKE_RGB24(rgb, 0, 0, 192),	/* blue */
	};
	const struct color_rgb24 colors_middle[] = {
		MAKE_RGB24(rgb, 0, 0, 192),	/* blue */
		MAKE_RGB24(rgb, 19, 19, 19),	/* black */
		MAKE_RGB24(rgb, 192, 0, 192),	/* magenta */
		MAKE_RGB24(rgb, 19, 19, 19),	/* black */
		MAKE_RGB24(rgb, 0, 192, 192),	/* cyan */
		MAKE_RGB24(rgb, 19, 19, 19),	/* black */
		MAKE_RGB24(rgb, 192, 192, 192),	/* grey */
	};
	const struct color_rgb24 colors_bottom[] = {
		MAKE_RGB24(rgb, 0, 33, 76),	/* in-phase */
		MAKE_RGB24(rgb, 255, 255, 255),	/* super white */
		MAKE_RGB24(rgb, 50, 0, 106),	/* quadrature */
		MAKE_RGB24(rgb, 19, 19, 19),	/* black */
		MAKE_RGB24(rgb, 9, 9, 9),	/* 3.5% */
		MAKE_RGB24(rgb, 19, 19, 19),	/* 7.5% */
		MAKE_RGB24(rgb, 29, 29, 29),	/* 11.5% */
		MAKE_RGB24(rgb, 19, 19, 19),	/* black */
	};
	unsigned int x;
	unsigned int y;

	for (y = 0; y < height * 6 / 9; ++y) {
		for (x = 0; x < width; ++x)
			((struct color_rgb24 *)mem)[x] =
				colors_top[x * 7 / width];
		mem += stride;
	}

	for (; y < height * 7 / 9; ++y) {
		for (x = 0; x < width; ++x)
			((struct color_rgb24 *)mem)[x] =
				colors_middle[x * 7 / width];
		mem += stride;
	}

	for (; y < height; ++y) {
		for (x = 0; x < width * 5 / 7; ++x)
			((struct color_rgb24 *)mem)[x] =
				colors_bottom[x * 4 / (width * 5 / 7)];
		for (; x < width * 6 / 7; ++x)
			((struct color_rgb24 *)mem)[x] =
				colors_bottom[(x - width * 5 / 7) * 3
					      / (width / 7) + 4];
		for (; x < width; ++x)
			((struct color_rgb24 *)mem)[x] = colors_bottom[7];
		mem += stride;
	}
}

static void fill_smpte_rgb32(const struct util_rgb_info *rgb, void *mem,
			     unsigned int width, unsigned int height,
			     unsigned int stride)
{
	const uint32_t colors_top[] = {
		MAKE_RGBA(rgb, 192, 192, 192, 255),	/* grey */
		MAKE_RGBA(rgb, 192, 192, 0, 255),	/* yellow */
		MAKE_RGBA(rgb, 0, 192, 192, 255),	/* cyan */
		MAKE_RGBA(rgb, 0, 192, 0, 255),		/* green */
		MAKE_RGBA(rgb, 192, 0, 192, 255),	/* magenta */
		MAKE_RGBA(rgb, 192, 0, 0, 255),		/* red */
		MAKE_RGBA(rgb, 0, 0, 192, 255),		/* blue */
	};
	const uint32_t colors_middle[] = {
		MAKE_RGBA(rgb, 0, 0, 192, 127),		/* blue */
		MAKE_RGBA(rgb, 19, 19, 19, 127),	/* black */
		MAKE_RGBA(rgb, 192, 0, 192, 127),	/* magenta */
		MAKE_RGBA(rgb, 19, 19, 19, 127),	/* black */
		MAKE_RGBA(rgb, 0, 192, 192, 127),	/* cyan */
		MAKE_RGBA(rgb, 19, 19, 19, 127),	/* black */
		MAKE_RGBA(rgb, 192, 192, 192, 127),	/* grey */
	};
	const uint32_t colors_bottom[] = {
		MAKE_RGBA(rgb, 0, 33, 76, 255),		/* in-phase */
		MAKE_RGBA(rgb, 255, 255, 255, 255),	/* super white */
		MAKE_RGBA(rgb, 50, 0, 106, 255),	/* quadrature */
		MAKE_RGBA(rgb, 19, 19, 19, 255),	/* black */
		MAKE_RGBA(rgb, 9, 9, 9, 255),		/* 3.5% */
		MAKE_RGBA(rgb, 19, 19, 19, 255),	/* 7.5% */
		MAKE_RGBA(rgb, 29, 29, 29, 255),	/* 11.5% */
		MAKE_RGBA(rgb, 19, 19, 19, 255),	/* black */
	};
	unsigned int x;
	unsigned int y;

	for (y = 0; y < height * 6 / 9; ++y) {
		for (x = 0; x < width; ++x)
			((uint32_t *)mem)[x] = colors_top[x * 7 / width];
		mem += stride;
	}

	for (; y < height * 7 / 9; ++y) {
		for (x = 0; x < width; ++x)
			((uint32_t *)mem)[x] = colors_middle[x * 7 / width];
		mem += stride;
	}

	for (; y < height; ++y) {
		for (x = 0; x < width * 5 / 7; ++x)
			((uint32_t *)mem)[x] =
				colors_bottom[x * 4 / (width * 5 / 7)];
		for (; x < width * 6 / 7; ++x)
			((uint32_t *)mem)[x] =
				colors_bottom[(x - width * 5 / 7) * 3
					      / (width / 7) + 4];
		for (; x < width; ++x)
			((uint32_t *)mem)[x] = colors_bottom[7];
		mem += stride;
	}
}

static void fill_smpte_rgb16fp(const struct util_rgb_info *rgb, void *mem,
			       unsigned int width, unsigned int height,
			       unsigned int stride)
{
	const uint64_t colors_top[] = {
		MAKE_RGBA8FP16(rgb, 192, 192, 192, 255),/* grey */
		MAKE_RGBA8FP16(rgb, 192, 192, 0, 255),	/* yellow */
		MAKE_RGBA8FP16(rgb, 0, 192, 192, 255),	/* cyan */
		MAKE_RGBA8FP16(rgb, 0, 192, 0, 255),	/* green */
		MAKE_RGBA8FP16(rgb, 192, 0, 192, 255),	/* magenta */
		MAKE_RGBA8FP16(rgb, 192, 0, 0, 255),	/* red */
		MAKE_RGBA8FP16(rgb, 0, 0, 192, 255),	/* blue */
	};
	const uint64_t colors_middle[] = {
		MAKE_RGBA8FP16(rgb, 0, 0, 192, 127),	/* blue */
		MAKE_RGBA8FP16(rgb, 19, 19, 19, 127),	/* black */
		MAKE_RGBA8FP16(rgb, 192, 0, 192, 127),	/* magenta */
		MAKE_RGBA8FP16(rgb, 19, 19, 19, 127),	/* black */
		MAKE_RGBA8FP16(rgb, 0, 192, 192, 127),	/* cyan */
		MAKE_RGBA8FP16(rgb, 19, 19, 19, 127),	/* black */
		MAKE_RGBA8FP16(rgb, 192, 192, 192, 127),/* grey */
	};
	const uint64_t colors_bottom[] = {
		MAKE_RGBA8FP16(rgb, 0, 33, 76, 255),	/* in-phase */
		MAKE_RGBA8FP16(rgb, 255, 255, 255, 255),/* super white */
		MAKE_RGBA8FP16(rgb, 50, 0, 106, 255),	/* quadrature */
		MAKE_RGBA8FP16(rgb, 19, 19, 19, 255),	/* black */
		MAKE_RGBA8FP16(rgb, 9, 9, 9, 255),	/* 3.5% */
		MAKE_RGBA8FP16(rgb, 19, 19, 19, 255),	/* 7.5% */
		MAKE_RGBA8FP16(rgb, 29, 29, 29, 255),	/* 11.5% */
		MAKE_RGBA8FP16(rgb, 19, 19, 19, 255),	/* black */
	};
	unsigned int x;
	unsigned int y;

	for (y = 0; y < height * 6 / 9; ++y) {
		for (x = 0; x < width; ++x)
			((uint64_t *)mem)[x] = colors_top[x * 7 / width];
		mem += stride;
	}

	for (; y < height * 7 / 9; ++y) {
		for (x = 0; x < width; ++x)
			((uint64_t *)mem)[x] = colors_middle[x * 7 / width];
		mem += stride;
	}

	for (; y < height; ++y) {
		for (x = 0; x < width * 5 / 7; ++x)
			((uint64_t *)mem)[x] =
				colors_bottom[x * 4 / (width * 5 / 7)];
		for (; x < width * 6 / 7; ++x)
			((uint64_t *)mem)[x] =
				colors_bottom[(x - width * 5 / 7) * 3
					      / (width / 7) + 4];
		for (; x < width; ++x)
			((uint64_t *)mem)[x] = colors_bottom[7];
		mem += stride;
	}
}

static void fill_smpte_c8(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)
			((uint8_t *)mem)[x] = x * 7 / width;
		mem += stride;
	}

	for (; y < height * 7 / 9; ++y) {
		for (x = 0; x < width; ++x)
			((uint8_t *)mem)[x] = 7 + (x * 7 / width);
		mem += stride;
	}

	for (; y < height; ++y) {
		for (x = 0; x < width * 5 / 7; ++x)
			((uint8_t *)mem)[x] =
				14 + (x * 4 / (width * 5 / 7));
		for (; x < width * 6 / 7; ++x)
			((uint8_t *)mem)[x] =
				14 + ((x - width * 5 / 7) * 3
					      / (width / 7) + 4);
		for (; x < width; ++x)
			((uint8_t *)mem)[x] = 14 + 7;
		mem += stride;
	}
}

void util_smpte_c8_gamma(unsigned size, struct drm_color_lut *lut)
{
	if (size < 7 + 7 + 8) {
		printf("Error: gamma too small: %d < %d\n", size, 7 + 7 + 8);
		return;
	}
	memset(lut, 0, size * sizeof(struct drm_color_lut));

#define FILL_COLOR(idx, r, g, b) \
	lut[idx].red = (r) << 8; \
	lut[idx].green = (g) << 8; \
	lut[idx].blue = (b) << 8

	FILL_COLOR( 0, 192, 192, 192);	/* grey */
	FILL_COLOR( 1, 192, 192, 0  );	/* yellow */
	FILL_COLOR( 2, 0,   192, 192);	/* cyan */
	FILL_COLOR( 3, 0,   192, 0  );	/* green */
	FILL_COLOR( 4, 192, 0,   192);	/* magenta */
	FILL_COLOR( 5, 192, 0,   0  );	/* red */
	FILL_COLOR( 6, 0,   0,   192);	/* blue */

	FILL_COLOR( 7, 0,   0,   192);	/* blue */
	FILL_COLOR( 8, 19,  19,  19 );	/* black */
	FILL_COLOR( 9, 192, 0,   192);	/* magenta */
	FILL_COLOR(10, 19,  19,  19 );	/* black */
	FILL_COLOR(11, 0,   192, 192);	/* cyan */
	FILL_COLOR(12, 19,  19,  19 );	/* black */
	FILL_COLOR(13, 192, 192, 192);	/* grey */

	FILL_COLOR(14, 0,   33,  76);	/* in-phase */
	FILL_COLOR(15, 255, 255, 255);	/* super white */
	FILL_COLOR(16, 50,  0,   106);	/* quadrature */
	FILL_COLOR(17, 19,  19,  19);	/* black */
	FILL_COLOR(18, 9,   9,   9);	/* 3.5% */
	FILL_COLOR(19, 19,  19,  19);	/* 7.5% */
	FILL_COLOR(20, 29,  29,  29);	/* 11.5% */
	FILL_COLOR(21, 19,  19,  19);	/* black */

#undef FILL_COLOR
}

static void fill_smpte(const struct util_format_info *info, void *planes[3],
		       unsigned int width, unsigned int height,
		       unsigned int stride)
{
	unsigned char *u, *v;

	switch (info->format) {
	case DRM_FORMAT_C8:
		return fill_smpte_c8(planes[0], width, height, stride);
	case DRM_FORMAT_UYVY:
	case DRM_FORMAT_VYUY:
	case DRM_FORMAT_YUYV:
	case DRM_FORMAT_YVYU:
		return fill_smpte_yuv_packed(&info->yuv, planes[0], width,
					     height, stride);

	case DRM_FORMAT_NV12:
	case DRM_FORMAT_NV21:
	case DRM_FORMAT_NV16:
	case DRM_FORMAT_NV61:
		u = info->yuv.order & YUV_YCbCr ? planes[1] : planes[1] + 1;
		v = info->yuv.order & YUV_YCrCb ? planes[1] : planes[1] + 1;
		return fill_smpte_yuv_planar(&info->yuv, planes[0], u, v,
					     width, height, stride);

	case DRM_FORMAT_YUV420:
		return fill_smpte_yuv_planar(&info->yuv, planes[0], planes[1],
					     planes[2], width, height, stride);

	case DRM_FORMAT_YVU420:
		return fill_smpte_yuv_planar(&info->yuv, planes[0], planes[2],
					     planes[1], width, height, stride);

	case DRM_FORMAT_ARGB4444:
	case DRM_FORMAT_XRGB4444:
	case DRM_FORMAT_ABGR4444:
	case DRM_FORMAT_XBGR4444:
	case DRM_FORMAT_RGBA4444:
	case DRM_FORMAT_RGBX4444:
	case DRM_FORMAT_BGRA4444:
	case DRM_FORMAT_BGRX4444:
	case DRM_FORMAT_RGB565:
	case DRM_FORMAT_BGR565:
	case DRM_FORMAT_ARGB1555:
	case DRM_FORMAT_XRGB1555:
	case DRM_FORMAT_ABGR1555:
	case DRM_FORMAT_XBGR1555:
	case DRM_FORMAT_RGBA5551:
	case DRM_FORMAT_RGBX5551:
	case DRM_FORMAT_BGRA5551:
	case DRM_FORMAT_BGRX5551:
		return fill_smpte_rgb16(&info->rgb, planes[0],
					width, height, stride);

	case DRM_FORMAT_BGR888:
	case DRM_FORMAT_RGB888:
		return fill_smpte_rgb24(&info->rgb, planes[0],
					width, height, stride);
	case DRM_FORMAT_ARGB8888:
	case DRM_FORMAT_XRGB8888:
	case DRM_FORMAT_ABGR8888:
	case DRM_FORMAT_XBGR8888:
	case DRM_FORMAT_RGBA8888:
	case DRM_FORMAT_RGBX8888:
	case DRM_FORMAT_BGRA8888:
	case DRM_FORMAT_BGRX8888:
	case DRM_FORMAT_ARGB2101010:
	case DRM_FORMAT_XRGB2101010:
	case DRM_FORMAT_ABGR2101010:
	case DRM_FORMAT_XBGR2101010:
	case DRM_FORMAT_RGBA1010102:
	case DRM_FORMAT_RGBX1010102:
	case DRM_FORMAT_BGRA1010102:
	case DRM_FORMAT_BGRX1010102:
		return fill_smpte_rgb32(&info->rgb, planes[0],
					width, height, stride);

	case DRM_FORMAT_XRGB16161616F:
	case DRM_FORMAT_XBGR16161616F:
	case DRM_FORMAT_ARGB16161616F:
	case DRM_FORMAT_ABGR16161616F:
		return fill_smpte_rgb16fp(&info->rgb, planes[0],
					  width, height, stride);
	}
}

/* swap these for big endian.. */
#define RED   2
#define GREEN 1
#define BLUE  0

static void make_pwetty(void *data, unsigned int width, unsigned int height,
			unsigned int stride, uint32_t format)
{
#if HAVE_CAIRO
	cairo_surface_t *surface;
	cairo_t *cr;
	cairo_format_t cairo_format;

	/* we can ignore the order of R,G,B channels */
	switch (format) {
	case DRM_FORMAT_XRGB8888:
	case DRM_FORMAT_ARGB8888:
	case DRM_FORMAT_XBGR8888:
	case DRM_FORMAT_ABGR8888:
		cairo_format = CAIRO_FORMAT_ARGB32;
		break;
	case DRM_FORMAT_RGB565:
	case DRM_FORMAT_BGR565:
		cairo_format = CAIRO_FORMAT_RGB16_565;
		break;
#if CAIRO_VERSION_MAJOR > 1 || (CAIRO_VERSION_MAJOR == 1 && CAIRO_VERSION_MINOR >= 12)
	case DRM_FORMAT_ARGB2101010:
	case DRM_FORMAT_XRGB2101010:
	case DRM_FORMAT_ABGR2101010:
	case DRM_FORMAT_XBGR2101010:
		cairo_format = CAIRO_FORMAT_RGB30;
		break;
#endif
	default:
		return;
	}

	surface = cairo_image_surface_create_for_data(data,
						      cairo_format,
						      width, height,
						      stride);
	cr = cairo_create(surface);
	cairo_surface_destroy(surface);

	cairo_set_line_cap(cr, CAIRO_LINE_CAP_SQUARE);
	for (unsigned x = 0; x < width; x += 250)
		for (unsigned y = 0; y < height; y += 250) {
			char buf[64];

			cairo_move_to(cr, x, y - 20);
			cairo_line_to(cr, x, y + 20);
			cairo_move_to(cr, x - 20, y);
			cairo_line_to(cr, x + 20, y);
			cairo_new_sub_path(cr);
			cairo_arc(cr, x, y, 10, 0, M_PI * 2);
			cairo_set_line_width(cr, 4);
			cairo_set_source_rgb(cr, 0, 0, 0);
			cairo_stroke_preserve(cr);
			cairo_set_source_rgb(cr, 1, 1, 1);
			cairo_set_line_width(cr, 2);
			cairo_stroke(cr);

			snprintf(buf, sizeof buf, "%d, %d", x, y);
			cairo_move_to(cr, x + 20, y + 20);
			cairo_text_path(cr, buf);
			cairo_set_source_rgb(cr, 0, 0, 0);
			cairo_stroke_preserve(cr);
			cairo_set_source_rgb(cr, 1, 1, 1);
			cairo_fill(cr);
		}

	cairo_destroy(cr);
#endif
}

static void fill_tiles_yuv_planar(const struct util_format_info *info,
				  unsigned char *y_mem, unsigned char *u_mem,
				  unsigned char *v_mem, unsigned int width,
				  unsigned int height, unsigned int stride)
{
	const struct util_yuv_info *yuv = &info->yuv;
	unsigned int cs = yuv->chroma_stride;
	unsigned int xsub = yuv->xsub;
	unsigned int ysub = yuv->ysub;
	unsigned int x;
	unsigned int y;

	for (y = 0; y < height; ++y) {
		for (x = 0; x < width; ++x) {
			div_t d = div(x+y, width);
			uint32_t rgb32 = 0x00130502 * (d.quot >> 6)
				       + 0x000a1120 * (d.rem >> 6);
			struct color_yuv color =
				MAKE_YUV_601((rgb32 >> 16) & 0xff,
					     (rgb32 >> 8) & 0xff, rgb32 & 0xff);

			y_mem[x] = color.y;
			u_mem[x/xsub*cs] = color.u;
			v_mem[x/xsub*cs] = color.v;
		}

		y_mem += stride;
		if ((y + 1) % ysub == 0) {
			u_mem += stride * cs / xsub;
			v_mem += stride * cs / xsub;
		}
	}
}

static void fill_tiles_yuv_packed(const struct util_format_info *info,
				  void *mem, unsigned int width,
				  unsigned int height, unsigned int stride)
{
	const struct util_yuv_info *yuv = &info->yuv;
	unsigned char *y_mem = (yuv->order & YUV_YC) ? mem : mem + 1;
	unsigned char *c_mem = (yuv->order & YUV_CY) ? mem : mem + 1;
	unsigned int u = (yuv->order & YUV_YCrCb) ? 2 : 0;
	unsigned int v = (yuv->order & YUV_YCbCr) ? 2 : 0;
	unsigned int x;
	unsigned int y;

	for (y = 0; y < height; ++y) {
		for (x = 0; x < width; x += 2) {
			div_t d = div(x+y, width);
			uint32_t rgb32 = 0x00130502 * (d.quot >> 6)
				       + 0x000a1120 * (d.rem >> 6);
			struct color_yuv color =
				MAKE_YUV_601((rgb32 >> 16) & 0xff,
					     (rgb32 >> 8) & 0xff, rgb32 & 0xff);

			y_mem[2*x] = color.y;
			c_mem[2*x+u] = color.u;
			y_mem[2*x+2] = color.y;
			c_mem[2*x+v] = color.v;
		}

		y_mem += stride;
		c_mem += stride;
	}
}

static void fill_tiles_rgb16(const struct util_format_info *info, void *mem,
			     unsigned int width, unsigned int height,
			     unsigned int stride)
{
	const struct util_rgb_info *rgb = &info->rgb;
	void *mem_base = mem;
	unsigned int x, y;

	for (y = 0; y < height; ++y) {
		for (x = 0; x < width; ++x) {
			div_t d = div(x+y, width);
			uint32_t rgb32 = 0x00130502 * (d.quot >> 6)
				       + 0x000a1120 * (d.rem >> 6);
			uint16_t color =
				MAKE_RGBA(rgb, (rgb32 >> 16) & 0xff,
					  (rgb32 >> 8) & 0xff, rgb32 & 0xff,
					  255);

			((uint16_t *)mem)[x] = color;
		}
		mem += stride;
	}

	make_pwetty(mem_base, width, height, stride, info->format);
}

static void fill_tiles_rgb24(const struct util_format_info *info, void *mem,
			     unsigned int width, unsigned int height,
			     unsigned int stride)
{
	const struct util_rgb_info *rgb = &info->rgb;
	unsigned int x, y;

	for (y = 0; y < height; ++y) {
		for (x = 0; x < width; ++x) {
			div_t d = div(x+y, width);
			uint32_t rgb32 = 0x00130502 * (d.quot >> 6)
				       + 0x000a1120 * (d.rem >> 6);
			struct color_rgb24 color =
				MAKE_RGB24(rgb, (rgb32 >> 16) & 0xff,
					   (rgb32 >> 8) & 0xff, rgb32 & 0xff);

			((struct color_rgb24 *)mem)[x] = color;
		}
		mem += stride;
	}
}

static void fill_tiles_rgb32(const struct util_format_info *info, void *mem,
			     unsigned int width, unsigned int height,
			     unsigned int stride)
{
	const struct util_rgb_info *rgb = &info->rgb;
	void *mem_base = mem;
	unsigned int x, y;

	for (y = 0; y < height; ++y) {
		for (x = 0; x < width; ++x) {
			div_t d = div(x+y, width);
			uint32_t rgb32 = 0x00130502 * (d.quot >> 6)
				       + 0x000a1120 * (d.rem >> 6);
			uint32_t alpha = ((y < height/2) && (x < width/2)) ? 127 : 255;
			uint32_t color =
				MAKE_RGBA(rgb, (rgb32 >> 16) & 0xff,
					  (rgb32 >> 8) & 0xff, rgb32 & 0xff,
					  alpha);

			((uint32_t *)mem)[x] = color;
		}
		mem += stride;
	}

	make_pwetty(mem_base, width, height, stride, info->format);
}

static void fill_tiles_rgb16fp(const struct util_format_info *info, void *mem,
			       unsigned int width, unsigned int height,
			       unsigned int stride)
{
	const struct util_rgb_info *rgb = &info->rgb;
	void *mem_base = mem;
	unsigned int x, y;

	/* TODO: Give this actual fp16 precision */
	for (y = 0; y < height; ++y) {
		for (x = 0; x < width; ++x) {
			div_t d = div(x+y, width);
			uint32_t rgb32 = 0x00130502 * (d.quot >> 6)
				       + 0x000a1120 * (d.rem >> 6);
			uint32_t alpha = ((y < height/2) && (x < width/2)) ? 127 : 255;
			uint64_t color =
				MAKE_RGBA8FP16(rgb, (rgb32 >> 16) & 0xff,
					       (rgb32 >> 8) & 0xff, rgb32 & 0xff,
					       alpha);

			((uint64_t *)mem)[x] = color;
		}
		mem += stride;
	}
}

static void fill_tiles(const struct util_format_info *info, void *planes[3],
		       unsigned int width, unsigned int height,
		       unsigned int stride)
{
	unsigned char *u, *v;

	switch (info->format) {
	case DRM_FORMAT_UYVY:
	case DRM_FORMAT_VYUY:
	case DRM_FORMAT_YUYV:
	case DRM_FORMAT_YVYU:
		return fill_tiles_yuv_packed(info, planes[0],
					     width, height, stride);

	case DRM_FORMAT_NV12:
	case DRM_FORMAT_NV21:
	case DRM_FORMAT_NV16:
	case DRM_FORMAT_NV61:
		u = info->yuv.order & YUV_YCbCr ? planes[1] : planes[1] + 1;
		v = info->yuv.order & YUV_YCrCb ? planes[1] : planes[1] + 1;
		return fill_tiles_yuv_planar(info, planes[0], u, v,
					     width, height, stride);

	case DRM_FORMAT_YUV420:
		return fill_tiles_yuv_planar(info, planes[0], planes[1],
					     planes[2], width, height, stride);

	case DRM_FORMAT_YVU420:
		return fill_tiles_yuv_planar(info, planes[0], planes[2],
					     planes[1], width, height, stride);

	case DRM_FORMAT_ARGB4444:
	case DRM_FORMAT_XRGB4444:
	case DRM_FORMAT_ABGR4444:
	case DRM_FORMAT_XBGR4444:
	case DRM_FORMAT_RGBA4444:
	case DRM_FORMAT_RGBX4444:
	case DRM_FORMAT_BGRA4444:
	case DRM_FORMAT_BGRX4444:
	case DRM_FORMAT_RGB565:
	case DRM_FORMAT_BGR565:
	case DRM_FORMAT_ARGB1555:
	case DRM_FORMAT_XRGB1555:
	case DRM_FORMAT_ABGR1555:
	case DRM_FORMAT_XBGR1555:
	case DRM_FORMAT_RGBA5551:
	case DRM_FORMAT_RGBX5551:
	case DRM_FORMAT_BGRA5551:
	case DRM_FORMAT_BGRX5551:
		return fill_tiles_rgb16(info, planes[0],
					width, height, stride);

	case DRM_FORMAT_BGR888:
	case DRM_FORMAT_RGB888:
		return fill_tiles_rgb24(info, planes[0],
					width, height, stride);
	case DRM_FORMAT_ARGB8888:
	case DRM_FORMAT_XRGB8888:
	case DRM_FORMAT_ABGR8888:
	case DRM_FORMAT_XBGR8888:
	case DRM_FORMAT_RGBA8888:
	case DRM_FORMAT_RGBX8888:
	case DRM_FORMAT_BGRA8888:
	case DRM_FORMAT_BGRX8888:
	case DRM_FORMAT_ARGB2101010:
	case DRM_FORMAT_XRGB2101010:
	case DRM_FORMAT_ABGR2101010:
	case DRM_FORMAT_XBGR2101010:
	case DRM_FORMAT_RGBA1010102:
	case DRM_FORMAT_RGBX1010102:
	case DRM_FORMAT_BGRA1010102:
	case DRM_FORMAT_BGRX1010102:
		return fill_tiles_rgb32(info, planes[0],
					width, height, stride);

	case DRM_FORMAT_XRGB16161616F:
	case DRM_FORMAT_XBGR16161616F:
	case DRM_FORMAT_ARGB16161616F:
	case DRM_FORMAT_ABGR16161616F:
		return fill_tiles_rgb16fp(info, planes[0],
					  width, height, stride);
	}
}

static void fill_plain(const struct util_format_info *info, void *planes[3],
		       unsigned int height,
		       unsigned int stride)
{
	switch (info->format) {
	case DRM_FORMAT_XRGB16161616F:
	case DRM_FORMAT_XBGR16161616F:
	case DRM_FORMAT_ARGB16161616F:
	case DRM_FORMAT_ABGR16161616F:
		/* 0x3838 = 0.5273 */
		memset(planes[0], 0x38, stride * height);
		break;
	default:
		memset(planes[0], 0x77, stride * height);
		break;
	}
}

static void fill_gradient_rgb32(const struct util_rgb_info *rgb,
				void *mem,
				unsigned int width, unsigned int height,
				unsigned int stride)
{
	int i, j;

	for (i = 0; i < height / 2; i++) {
		uint32_t *row = mem;

		for (j = 0; j < width / 2; j++) {
			uint32_t value = MAKE_RGBA10(rgb, j & 0x3ff, j & 0x3ff, j & 0x3ff, 0);
			row[2*j] = row[2*j+1] = value;
		}
		mem += stride;
	}

	for (; i < height; i++) {
		uint32_t *row = mem;

		for (j = 0; j < width / 2; j++) {
			uint32_t value = MAKE_RGBA10(rgb, j & 0x3fc, j & 0x3fc, j & 0x3fc, 0);
			row[2*j] = row[2*j+1] = value;
		}
		mem += stride;
	}
}

static void fill_gradient_rgb16fp(const struct util_rgb_info *rgb,
				  void *mem,
				  unsigned int width, unsigned int height,
				  unsigned int stride)
{
	int i, j;

	for (i = 0; i < height / 2; i++) {
		uint64_t *row = mem;

		for (j = 0; j < width / 2; j++) {
			uint64_t value = MAKE_RGBA10FP16(rgb, j & 0x3ff, j & 0x3ff, j & 0x3ff, 0);
			row[2*j] = row[2*j+1] = value;
		}
		mem += stride;
	}

	for (; i < height; i++) {
		uint64_t *row = mem;

		for (j = 0; j < width / 2; j++) {
			uint64_t value = MAKE_RGBA10FP16(rgb, j & 0x3fc, j & 0x3fc, j & 0x3fc, 0);
			row[2*j] = row[2*j+1] = value;
		}
		mem += stride;
	}
}

/* The gradient pattern creates two horizontal gray gradients, split
 * into two halves. The top half has 10bpc precision, the bottom half
 * has 8bpc precision. When using with a 10bpc fb format, there are 3
 * possible outcomes:
 *
 *  - Pixel data is encoded as 8bpc to the display, no dithering. This
 *    would lead to the top and bottom halves looking identical.
 *
 *  - Pixel data is encoded as 8bpc to the display, with dithering. This
 *    would lead to there being a visible difference between the two halves,
 *    but the top half would look a little speck-y due to the dithering.
 *
 *  - Pixel data is encoded at 10bpc+ to the display (which implies
 *    the display is able to show this level of depth). This should
 *    lead to the top half being a very clean gradient, and visibly different
 *    from the bottom half.
 *
 * Once we support additional fb formats, this approach could be extended
 * to distinguish even higher bpc precisions.
 *
 * Note that due to practical size considerations, for the screens
 * where this matters, the pattern actually emits stripes 2-pixels
 * wide for each gradient color. Otherwise the difference may be a bit
 * hard to notice.
 */
static void fill_gradient(const struct util_format_info *info, void *planes[3],
			  unsigned int width, unsigned int height,
			  unsigned int stride)
{
	switch (info->format) {
	case DRM_FORMAT_ARGB8888:
	case DRM_FORMAT_XRGB8888:
	case DRM_FORMAT_ABGR8888:
	case DRM_FORMAT_XBGR8888:
	case DRM_FORMAT_RGBA8888:
	case DRM_FORMAT_RGBX8888:
	case DRM_FORMAT_BGRA8888:
	case DRM_FORMAT_BGRX8888:
	case DRM_FORMAT_ARGB2101010:
	case DRM_FORMAT_XRGB2101010:
	case DRM_FORMAT_ABGR2101010:
	case DRM_FORMAT_XBGR2101010:
	case DRM_FORMAT_RGBA1010102:
	case DRM_FORMAT_RGBX1010102:
	case DRM_FORMAT_BGRA1010102:
	case DRM_FORMAT_BGRX1010102:
		return fill_gradient_rgb32(&info->rgb, planes[0],
					   width, height, stride);

	case DRM_FORMAT_XRGB16161616F:
	case DRM_FORMAT_XBGR16161616F:
	case DRM_FORMAT_ARGB16161616F:
	case DRM_FORMAT_ABGR16161616F:
		return fill_gradient_rgb16fp(&info->rgb, planes[0],
					     width, height, stride);
	}
}

/*
 * util_fill_pattern - Fill a buffer with a test pattern
 * @format: Pixel format
 * @pattern: Test pattern
 * @planes: Array of buffers
 * @width: Width in pixels
 * @height: Height in pixels
 * @stride: Line stride (pitch) in bytes
 *
 * Fill the buffers with the test pattern specified by the pattern parameter.
 * Supported formats vary depending on the selected pattern.
 */
void util_fill_pattern(uint32_t format, enum util_fill_pattern pattern,
		       void *planes[3], unsigned int width,
		       unsigned int height, unsigned int stride)
{
	const struct util_format_info *info;

	info = util_format_info_find(format);
	if (info == NULL)
		return;

	switch (pattern) {
	case UTIL_PATTERN_TILES:
		return fill_tiles(info, planes, width, height, stride);

	case UTIL_PATTERN_SMPTE:
		return fill_smpte(info, planes, width, height, stride);

	case UTIL_PATTERN_PLAIN:
		return fill_plain(info, planes, height, stride);

	case UTIL_PATTERN_GRADIENT:
		return fill_gradient(info, planes, width, height, stride);

	default:
		printf("Error: unsupported test pattern %u.\n", pattern);
		break;
	}
}

static const char *pattern_names[] = {
	[UTIL_PATTERN_TILES] = "tiles",
	[UTIL_PATTERN_SMPTE] = "smpte",
	[UTIL_PATTERN_PLAIN] = "plain",
	[UTIL_PATTERN_GRADIENT] = "gradient",
};

enum util_fill_pattern util_pattern_enum(const char *name)
{
	unsigned int i;

	for (i = 0; i < ARRAY_SIZE(pattern_names); i++)
		if (!strcmp(pattern_names[i], name))
			return (enum util_fill_pattern)i;

	printf("Error: unsupported test pattern %s.\n", name);
	return UTIL_PATTERN_SMPTE;
}