move rgb<->hsl sksl to common spot
We'll want to reuse these for other HSL effects, e.g. matrix filter.
Any preference where they go? New header?
Change-Id: I64534d9801b8bdecf0ef22b3517f8232de998170
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/370712
Reviewed-by: Brian Osman <brianosman@google.com>
diff --git a/src/core/SkRuntimeEffectPriv.h b/src/core/SkRuntimeEffectPriv.h
index f1ec190..b44d1e2 100644
--- a/src/core/SkRuntimeEffectPriv.h
+++ b/src/core/SkRuntimeEffectPriv.h
@@ -14,4 +14,37 @@
*/
void SkRuntimeEffect_SetInlineThreshold(int threshold);
+// This is mostly from skvm's rgb->hsl code, with some GPU-related finesse pulled from
+// GrHighContrastFilterEffect.fp, see next comment.
+constexpr char kRGB_to_HSL_sksl[] =
+ "half3 rgb_to_hsl(half3 c) {"
+ "half mx = max(max(c.r,c.g),c.b),"
+ " mn = min(min(c.r,c.g),c.b),"
+ " d = mx-mn, "
+ " invd = 1.0 / d, "
+ " g_lt_b = c.g < c.b ? 6.0 : 0.0;"
+
+ // We'd prefer to write these tests like `mx == c.r`, but on some GPUs max(x,y) is
+ // not always equal to either x or y. So we use long form, c.r >= c.g && c.r >= c.b.
+ "half h = (1/6.0) * (mx == mn ? 0.0 :"
+ " /*mx==c.r*/ c.r >= c.g && c.r >= c.b ? invd * (c.g - c.b) + g_lt_b :"
+ " /*mx==c.g*/ c.g >= c.b ? invd * (c.b - c.r) + 2.0 "
+ " /*mx==c.b*/ : invd * (c.r - c.g) + 4.0);"
+
+ "half sum = mx+mn,"
+ " l = sum * 0.5,"
+ " s = mx == mn ? 0.0"
+ " : d / (l > 0.5 ? 2.0 - sum : sum);"
+ "return half3(h,s,l);"
+ "}";
+
+//This is straight out of GrHSLToRGBFilterEffect.fp.
+constexpr char kHSL_to_RGB_sksl[] =
+ "half3 hsl_to_rgb(half3 hsl) {"
+ "half C = (1 - abs(2 * hsl.z - 1)) * hsl.y;"
+ "half3 p = hsl.xxx + half3(0, 2/3.0, 1/3.0);"
+ "half3 q = saturate(abs(fract(p) * 6 - 3) - 1);"
+ "return (q - 0.5) * C + hsl.z;"
+ "}";
+
#endif
diff --git a/src/effects/SkHighContrastFilter.cpp b/src/effects/SkHighContrastFilter.cpp
index b5d436d..874dd47 100644
--- a/src/effects/SkHighContrastFilter.cpp
+++ b/src/effects/SkHighContrastFilter.cpp
@@ -9,6 +9,7 @@
#include "include/effects/SkHighContrastFilter.h"
#include "include/effects/SkRuntimeEffect.h"
#include "include/private/SkTPin.h"
+#include "src/core/SkRuntimeEffectPriv.h"
sk_sp<SkColorFilter> SkHighContrastFilter::Make(const SkHighContrastConfig& userConfig) {
if (!userConfig.isValid()) {
@@ -26,39 +27,11 @@
SkString code{
"uniform shader input;"
"uniform half M;"
-
- //This is straight out of GrHSLToRGBFilterEffect.fp.
- "half3 hsl_to_rgb(half3 hsl) {"
- "half C = (1 - abs(2 * hsl.z - 1)) * hsl.y;"
- "half3 p = hsl.xxx + half3(0, 2/3.0, 1/3.0);"
- "half3 q = saturate(abs(fract(p) * 6 - 3) - 1);"
- "return (q - 0.5) * C + hsl.z;"
- "}"
-
- // This is mostly from skvm's rgb->hsl code, with some GPU-related finesse pulled from
- // GrHighContrastFilterEffect.fp, see next comment.
- "half3 rgb_to_hsl(half3 c) {"
- "half mx = max(max(c.r,c.g),c.b),"
- " mn = min(min(c.r,c.g),c.b),"
- " d = mx-mn, "
- " invd = 1.0 / d, "
- " g_lt_b = c.g < c.b ? 6.0 : 0.0;"
-
- // We'd prefer to write these tests like `mx == c.r`, but on some GPUs max(x,y) is
- // not always equal to either x or y. So we use long form, c.r >= c.g && c.r >= c.b.
- "half h = (1/6.0) * (mx == mn ? 0.0 :"
- " /*mx==c.r*/ c.r >= c.g && c.r >= c.b ? invd * (c.g - c.b) + g_lt_b :"
- " /*mx==c.g*/ c.g >= c.b ? invd * (c.b - c.r) + 2.0 "
- " /*mx==c.b*/ : invd * (c.r - c.g) + 4.0);"
-
- "half sum = mx+mn,"
- " l = sum * 0.5,"
- " s = mx == mn ? 0.0"
- " : d / (l > 0.5 ? 2.0 - sum : sum);"
- "return half3(h,s,l);"
- "}"
};
+ code += kRGB_to_HSL_sksl;
+ code += kHSL_to_RGB_sksl;
+
code += "half4 main() {";
if (true) {
code += "half4 c = sample(input);"; // c is linear unpremul RGBA in the dst gamut.
