Fix T54225: Blur node stopped working when Map Range was fed with image

The issue was happening with fast Gaussian blur, and caused by NaN value pixels
in the input buffer.

Now made it so Map Range output does not produce NaN, by returning arbitrary
value of 0. Still better than NaN!

1 files changed, 5 insertions, 0 deletions

diff --git a/source/blender/compositor/operations/COM_MapRangeOperation.cpp b/source/blender/compositor/operations/COM_MapRangeOperation.cpp
index 7a89ba91b4c..7a38d066122 100644
--- a/source/blender/compositor/operations/COM_MapRangeOperation.cpp
+++ b/source/blender/compositor/operations/COM_MapRangeOperation.cpp
@@ -65,6 +65,11 @@ void MapRangeOperation::executePixelSampled(float output[4], float x, float y, P
 	dest_min = inputs[3];
 	dest_max = inputs[4];
 
+	if (fabsf(source_max - source_min) < 1e-6f) {
+		output[0] = 0.0f;
+		return;
+	}
+
 	if (value >= -BLENDER_ZMAX && value <= BLENDER_ZMAX) {
 		value = (value - source_min) / (source_max - source_min);
 		value = dest_min + value * (dest_max - dest_min);