Fix hsvColor returning a NaN hue for achromatic (grey) colors - #1454
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Sreekant13 wants to merge 1 commit into
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hsvColor() divides by Delta (max - min) when computing the hue, but only guarded against max == 0, not Delta == 0. For any grey where r == g == b > 0, Delta is 0, so the hue became 60 * 0 / 0 = NaN (e.g. hsvColor(vec3(0.5)) gave a NaN hue instead of 0). Guard the achromatic case and set the hue to 0, consistent with the reverse rgbColor() which already special-cases achromatic colors. Add a regression test covering a grey input and its round-trip.
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Hi @Groovounet, gentle nudge on this one. It fixes a NaN hue returned for achromatic colours, with a test covering it. No rush. Thank you for maintaining glm. |
Author
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Hi @Groovounet, a gentle check-in on this one whenever you have a moment.
The PR is mergeable and green. No rush, and thank you for GLM. |
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hsvColor()computes the hue by dividing byDelta = max - min, but it only guards againstmax == 0, notDelta == 0. For any achromatic color wherer == g == b > 0(a grey),Deltais0, so the hue becomes60 * 0 / 0 = NaN:The reverse function
rgbColor()already special-cases achromatic colors (if(hsv.y == 0)), so this makeshsvColor()consistent: whenDelta == 0the hue is undefined and set to0(saturation is already0). Colored inputs are unchanged.Added a regression test in test/gtx/gtx_color_space.cpp covering a grey input (hue must be
0, notNaN) and its round-trip.