From: Steinar H. Gunderson <sgunderson@bigfoot.com>
Date: Sat, 21 Feb 2015 14:33:33 +0000 (+0100)
Subject: Fix combining in ResampleEffect again.
X-Git-Tag: 1.1.3~13
X-Git-Url: https://git.sesse.net/?p=movit;a=commitdiff_plain;h=fe7a508885d19950c43e46dc60db675375f49ffb

Fix combining in ResampleEffect again.

It was completely broken after the last patch, so we'd effectively
never combine.
---

diff --git a/resample_effect_test.cpp b/resample_effect_test.cpp
index 9082b26..5b620fd 100644
--- a/resample_effect_test.cpp
+++ b/resample_effect_test.cpp
@@ -96,11 +96,11 @@ TEST(ResampleEffectTest, DownscaleByTwoGetsCorrectPixelCenters) {
 	// the texel center right (everything is nicely symmetric).
 	// The approximate magnitudes have been checked against ImageMagick.
 	float expected_data[size * size] = {
-		 0.0046, -0.0068, -0.0611, -0.0068,  0.0047,
-		-0.0068,  0.0100,  0.0895,  0.0100, -0.0068,
-		-0.0603,  0.0892,  0.7993,  0.0895, -0.0611,
-		-0.0067,  0.0100,  0.0892,  0.0100, -0.0068,
-		 0.0045, -0.0067, -0.0603, -0.0068,  0.0046,
+		 0.0045, -0.0067, -0.0599, -0.0067,  0.0045,
+		-0.0067,  0.0100,  0.0892,  0.0100, -0.0067,
+		-0.0599,  0.0890,  0.7925,  0.0892, -0.0599,
+		-0.0067,  0.0100,  0.0890,  0.0100, -0.0067,
+		 0.0045, -0.0067, -0.0599, -0.0067,  0.0045,
 	};
 	float data[size * size * 4], out_data[size * size];
 
@@ -205,7 +205,7 @@ TEST(ResampleEffectTest, HeavyResampleGetsSumRight) {
 	// Require that we are within 10-bit accuracy. Note that this limit is for
 	// one pass only, but the limit is tight enough that it should be good enough
 	// for 10-bit accuracy even after two passes.
-	expect_equal(expected_data, out_data, dwidth, dheight, 0.1 / 1023.0);
+	expect_equal(expected_data, out_data, dwidth, dheight, 0.12 / 1023.0);
 }
 
 TEST(ResampleEffectTest, ReadWholePixelFromLeft) {
diff --git a/util.cpp b/util.cpp
index 61f3e4d..7fbc67a 100644
--- a/util.cpp
+++ b/util.cpp
@@ -174,7 +174,7 @@ void combine_two_samples(float w1, float w2, float pos1, float pos2, unsigned si
 	if (rounding_behavior == COMBINE_ROUND_TO_FP16) {	
 		// Round to fp16. Note that this might take z outside the 0..1 range.
 		*offset = fp16_to_fp64(fp64_to_fp16(*offset));
-		z = (z - pos1) / (pos2 - pos1);
+		z = (*offset - pos1) / (pos2 - pos1);
 	} else {
 		assert(rounding_behavior == COMBINE_DO_NOT_ROUND);
 	}