tests/color-icc-output: compare_float() to rgb_diff_stat

compare_float() was an ad hoc max error logger with optional debug
logging.

Now that we have rgb_diff_stat, we can get the same statistics and more
with less code. It looks like we would lose the pixel index x, but that
can be recovered from the dump file line number.

This patch takes care to keep the test condition exactly the same as it
was before. The statistics print-out has more details now.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>

tests/color-icc-output-test.c

@@ -27,6 +27,7 @@
 
 #include <math.h>
 #include <string.h>
+#include <stdio.h>
 #include <linux/limits.h>
 
 #include <lcms2.h>
@@ -513,67 +514,32 @@ gen_ramp_rgb(pixman_image_t *image, int bitwidth, int width_bar)
 }
 
 static bool
-compare_float(float ref, float dst, int x, const char *chan,
-	      float *max_diff, float max_allow_diff)
+process_pipeline_comparison(const struct buffer *src_buf,
+			    const struct buffer *shot_buf,
+			    const struct setup_args * arg)
 {
+	FILE *dump = NULL;
 #if 0
 	/*
-	 * This file can be loaded in Octave for visualization.
-	 *
-	 * S = load('compare_float_dump.txt');
+	 * This file can be loaded in Octave for visualization. Find the script
+	 * in tests/visualization/weston_plot_rgb_diff_stat.m and call it with
 	 *
-	 * rvec = S(S(:,1)==114, 2:3);
-	 * gvec = S(S(:,1)==103, 2:3);
-	 * bvec = S(S(:,1)==98, 2:3);
-	 *
-	 * figure
-	 * subplot(3, 1, 1);
-	 * plot(rvec(:,1), rvec(:,2) .* 255, 'r');
-	 * subplot(3, 1, 2);
-	 * plot(gvec(:,1), gvec(:,2) .* 255, 'g');
-	 * subplot(3, 1, 3);
-	 * plot(bvec(:,1), bvec(:,2) .* 255, 'b');
+	 * weston_plot_rgb_diff_stat('opaque_pixel_conversion-f05-dump.txt')
 	 */
-	static FILE *fp = NULL;
-
-	if (!fp)
-		fp = fopen("compare_float_dump.txt", "w");
-	fprintf(fp, "%d %d %f\n", chan[0], x, dst - ref);
-	fflush(fp);
+	dump = fopen_dump_file("dump");
 #endif
 
-	float diff  = fabsf(ref - dst);
-
-	if (diff > *max_diff)
-		*max_diff = diff;
-
-	if (diff <= max_allow_diff)
-		return true;
-
-	testlog("x=%d %s: ref %f != dst %f, delta %f\n",
-			x, chan, ref, dst, dst - ref);
-
-	return false;
-}
-
-static bool
-process_pipeline_comparison(const struct buffer *src_buf,
-			    const struct buffer *shot_buf,
-			    const struct setup_args * arg)
-{
-	const char *const chan_name[COLOR_CHAN_NUM] = { "r", "g", "b" };
 	const float max_pixel_value = 255.0;
-	struct color_float max_diff_pipeline = { .rgb = { 0.0f, 0.0f, 0.0f } };
 	float max_allow_diff = arg->tolerance / max_pixel_value;
-	float max_err = 0.0f;
 	bool ok = true;
 	struct image_header ih_src = image_header_from(src_buf->image);
 	struct image_header ih_shot = image_header_from(shot_buf->image);
 	int y, x;
-	int chan;
+	unsigned i;
 	struct color_float pix_src;
 	struct color_float pix_src_pipeline;
 	struct color_float pix_shot;
+	struct rgb_diff_stat diffstat = { .dump = dump };
 
 	/* no point to compare different images */
 	assert(ih_src.width == ih_shot.width);
@@ -586,33 +552,34 @@ process_pipeline_comparison(const struct buffer *src_buf,
 		for (x = 0; x < ih_src.width; x++) {
 			pix_src = a8r8g8b8_to_float(row_ptr[x]);
 			pix_shot = a8r8g8b8_to_float(row_ptr_shot[x]);
-			/* do pipeline processing */
+
 			process_pixel_using_pipeline(arg->pipeline->pre_fn,
 						     &arg->pipeline->mat,
 						     arg->pipeline->post_fn,
 						     &pix_src, &pix_src_pipeline);
 
-			/* check if pipeline matches to shader variant */
-			for (chan = 0; chan < COLOR_CHAN_NUM; chan++) {
-				ok &= compare_float(pix_src_pipeline.rgb[chan],
-						    pix_shot.rgb[chan],
-						    x, chan_name[chan],
-						    &max_diff_pipeline.rgb[chan],
-						    max_allow_diff);
-			}
+			rgb_diff_stat_update(&diffstat,
+					     &pix_src_pipeline, &pix_shot,
+					     &pix_src);
 		}
 	}
 
-	for (chan = 0; chan < COLOR_CHAN_NUM; chan++)
-		max_err = MAX(max_err, max_diff_pipeline.rgb[chan]);
+	for (i = 0; i < COLOR_CHAN_NUM; i++) {
+		if (diffstat.rgb[i].min < -max_allow_diff ||
+		    diffstat.rgb[i].max > max_allow_diff)
+			ok = false;
+	}
 
-	testlog("%s %s %s tol_req %d, tol_cal %f, max diff: r=%f, g=%f, b=%f %s\n",
-		__func__, ok == true? "SUCCESS":"FAILURE",
+	testlog("%s %s %s tol_req %d %s\n", __func__,
+		ok ? "SUCCESS" : "FAILURE",
 		arg->meta.name, arg->tolerance,
-		max_err * max_pixel_value,
-		max_diff_pipeline.r, max_diff_pipeline.g, max_diff_pipeline.b,
 		arg->type == PTYPE_MATRIX_SHAPER ? "matrix-shaper" : "cLUT");
 
+	rgb_diff_stat_print(&diffstat, __func__, 8);
+
+	if (dump)
+		fclose(dump);
+
 	return ok;
 }