bug fix in hsl GM reference impls

As written the "constants" in clip() and channel() change as we update
each channel... duh.  Thankfully this ought to make most GMs look good.

Change-Id: I904e20e8e5114c827233dd1a93c0c59f7e7790fa
Reviewed-on: https://skia-review.googlesource.com/15680
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Mike Klein <mtklein@chromium.org>

1 files changed, 11 insertions, 11 deletions

diff --git a/gm/hsl.cpp b/gm/hsl.cpp
index 120eebffe4..db604c02b9 100644
--- a/gm/hsl.cpp
+++ b/gm/hsl.cpp
@@ -46,9 +46,9 @@ static float lum(float r, float g, float b) { return r*0.30f + g*0.59f + b*0.11f
 // Both map the minimum channel to 0, maximum to s, and scale the middle proportionately.
 // The KHR version has done a better job at simplifying its math, so we use it here.
 static void set_sat(float* r, float* g, float* b, float s) {
-    auto channel = [&](float c) {
-        float mn = min(*r,*g,*b),
-              mx = max(*r,*g,*b);
+    float mn = min(*r,*g,*b),
+          mx = max(*r,*g,*b);
+    auto channel = [=](float c) {
         return mx == mn ? 0
                         : (c - mn) * s / (mx - mn);
     };
@@ -66,10 +66,10 @@ static void set_lum(float* r, float* g, float* b, float l) {
 }
 
 static void clip_color_web(float* r, float* g, float* b) {
-    auto clip = [&](float c) {
-        float l  = lum(*r,*g,*b),
-              mn = min(*r,*g,*b),
-              mx = max(*r,*g,*b);
+    float l  = lum(*r,*g,*b),
+          mn = min(*r,*g,*b),
+          mx = max(*r,*g,*b);
+    auto clip = [=](float c) {
         if (mn < 0) { c = l + (c - l) * (    l) / (l - mn); }
         if (mx > 1) { c = l + (c - l) * (1 - l) / (mx - l); }  // <--- notice "1-l"
       //SkASSERT(0 <= c);   // This may end up very slightly negative...
@@ -81,10 +81,10 @@ static void clip_color_web(float* r, float* g, float* b) {
     *b = clip(*b);
 }
 static void clip_color_KHR(float* r, float* g, float* b) {
-    auto clip = [&](float c) {
-        float l  = lum(*r,*g,*b),
-              mn = min(*r,*g,*b),
-              mx = max(*r,*g,*b);
+    float l  = lum(*r,*g,*b),
+          mn = min(*r,*g,*b),
+          mx = max(*r,*g,*b);
+    auto clip = [=](float c) {
         if (mn < 0) { c = l + (c - l) * l / (l - mn); }
         if (mx > 1) { c = l + (c - l) * l / (mx - l); }  // <--- notice "l"
       //SkASSERT(0 <= c);   // This may end up very slightly negative...