Nodes: Add general Combine/Separate Color nodes

Inspired by D12936 and D12929, this patch adds general purpose
"Combine Color" and "Separate Color" nodes to Geometry, Compositor,
Shader and Texture nodes.
- Within Geometry Nodes, it replaces the existing "Combine RGB" and
  "Separate RGB" nodes.
- Within Compositor Nodes, it replaces the existing
  "Combine RGBA/HSVA/YCbCrA/YUVA" and "Separate RGBA/HSVA/YCbCrA/YUVA"
  nodes.
- Within Texture Nodes, it replaces the existing "Combine RGBA" and
  "Separate RGBA" nodes.
- Within Shader Nodes, it replaces the existing "Combine RGB/HSV" and
  "Separate RGB/HSV" nodes.

Python addons have not been updated to the new nodes yet.

**New shader code**
In node_color.h, color.h and gpu_shader_material_color_util.glsl,
missing methods hsl_to_rgb and rgb_to_hsl are added by directly
converting existing C code. They always produce the same result.

**Old code**
As requested by T96219, old nodes still exist but are not displayed in
the add menu. This means Python scripts can still create them as usual.
Otherwise, versioning replaces the old nodes with the new nodes when
opening .blend files.

Differential Revision: https://developer.blender.org/D14034

4 files changed, 90 insertions, 0 deletions

diff --git a/intern/cycles/kernel/osl/shaders/CMakeLists.txt b/intern/cycles/kernel/osl/shaders/CMakeLists.txt
index 7ced21c5670..741bce7c399 100644
--- a/intern/cycles/kernel/osl/shaders/CMakeLists.txt
+++ b/intern/cycles/kernel/osl/shaders/CMakeLists.txt
@@ -16,6 +16,7 @@ set(SRC_OSL
   node_camera.osl
   node_checker_texture.osl
   node_clamp.osl
+  node_combine_color.osl
   node_combine_rgb.osl
   node_combine_hsv.osl
   node_combine_xyz.osl
@@ -68,6 +69,7 @@ set(SRC_OSL
   node_refraction_bsdf.osl
   node_rgb_curves.osl
   node_rgb_ramp.osl
+  node_separate_color.osl
   node_separate_rgb.osl
   node_separate_hsv.osl
   node_separate_xyz.osl
diff --git a/intern/cycles/kernel/osl/shaders/node_color.h b/intern/cycles/kernel/osl/shaders/node_color.h
index 388dd114e9a..06735f5b03d 100644
--- a/intern/cycles/kernel/osl/shaders/node_color.h
+++ b/intern/cycles/kernel/osl/shaders/node_color.h
@@ -148,3 +148,53 @@ color hsv_to_rgb(color hsv)
 
   return rgb;
 }
+
+color rgb_to_hsl(color rgb)
+{
+  float cmax, cmin, h, s, l;
+
+  cmax = max(rgb[0], max(rgb[1], rgb[2]));
+  cmin = min(rgb[0], min(rgb[1], rgb[2]));
+  l = min(1.0, (cmax + cmin) / 2.0);
+
+  if (cmax == cmin) {
+    h = s = 0.0; /* achromatic */
+  }
+  else {
+    float cdelta = cmax - cmin;
+    s = l > 0.5 ? cdelta / (2.0 - cmax - cmin) : cdelta / (cmax + cmin);
+    if (cmax == rgb[0]) {
+      h = (rgb[1] - rgb[2]) / cdelta + (rgb[1] < rgb[2] ? 6.0 : 0.0);
+    }
+    else if (cmax == rgb[1]) {
+      h = (rgb[2] - rgb[0]) / cdelta + 2.0;
+    }
+    else {
+      h = (rgb[0] - rgb[1]) / cdelta + 4.0;
+    }
+  }
+  h /= 6.0;
+
+  return color(h, s, l);
+}
+
+color hsl_to_rgb(color hsl)
+{
+  float nr, ng, nb, chroma, h, s, l;
+
+  h = hsl[0];
+  s = hsl[1];
+  l = hsl[2];
+
+  nr = abs(h * 6.0 - 3.0) - 1.0;
+  ng = 2.0 - abs(h * 6.0 - 2.0);
+  nb = 2.0 - abs(h * 6.0 - 4.0);
+
+  nr = clamp(nr, 0.0, 1.0);
+  nb = clamp(nb, 0.0, 1.0);
+  ng = clamp(ng, 0.0, 1.0);
+
+  chroma = (1.0 - abs(2.0 * l - 1.0)) * s;
+
+  return color((nr - 0.5) * chroma + l, (ng - 0.5) * chroma + l, (nb - 0.5) * chroma + l);
+}
diff --git a/intern/cycles/kernel/osl/shaders/node_combine_color.osl b/intern/cycles/kernel/osl/shaders/node_combine_color.osl
new file mode 100644
index 00000000000..94d624d82ad
--- /dev/null
+++ b/intern/cycles/kernel/osl/shaders/node_combine_color.osl
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: Apache-2.0
+ * Copyright 2011-2022 Blender Foundation */
+
+#include "stdcycles.h"
+
+shader node_combine_color(string color_type = "rgb", float Red = 0.0, float Green = 0.0, float Blue = 0.0, output color Color = 0.8)
+{
+  if (color_type == "rgb" || color_type == "hsv" || color_type == "hsl")
+    Color = color(color_type, Red, Green, Blue);
+  else
+    warning("%s", "Unknown color space!");
+}
diff --git a/intern/cycles/kernel/osl/shaders/node_separate_color.osl b/intern/cycles/kernel/osl/shaders/node_separate_color.osl
new file mode 100644
index 00000000000..cba2d85da05
--- /dev/null
+++ b/intern/cycles/kernel/osl/shaders/node_separate_color.osl
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: Apache-2.0
+ * Copyright 2011-2022 Blender Foundation */
+
+#include "node_color.h"
+#include "stdcycles.h"
+
+shader node_separate_color(string color_type = "rgb",
+                         color Color = 0.8,
+                         output float Red = 0.0,
+                         output float Green = 0.0,
+                         output float Blue = 0.0)
+{
+  color col;
+  if (color_type == "rgb")
+    col = Color;
+  else if (color_type == "hsv")
+    col = rgb_to_hsv(Color);
+  else if (color_type == "hsl")
+    col = rgb_to_hsl(Color);
+  else
+    warning("%s", "Unknown color space!");
+
+  Red = col[0];
+  Green = col[1];
+  Blue = col[2];
+}