primaries: added wconv parameter

Selects between standard chromatic adaptation and full gamut conversion.

doc/fmtconv.html

@@ -959,6 +959,7 @@ <h3><a id="primaries"></a>primaries</h3>
 	wd    : float[]: opt;
 	prims : data   : opt;
 	primd : data   : opt;
+	wconv : int    : opt; (False)
 	cpuopt: int    : opt; (-1)
 )</pre></td>
 <td class="n"><pre class="proto">fmtc_primaries (
@@ -973,6 +974,7 @@ <h3><a id="primaries"></a>primaries</h3>
 	arrayf wd (undefined),
 	string prims (undefined),
 	string primd (undefined),
+	bool   wconv (False),
 	int    cpuopt (-1)
 )</pre></td>
 </tr>
@@ -1070,6 +1072,21 @@ <h4>Parameters</h4>
 <tr><td><b><code>&quot;redwide&quot;</code></b></td><td>R<br />G<br />B<br />W (D65)</td><td>0.780308,<br />0.121595,<br />0.095612,<br />0.3217,</td><td>0.304253<br />1.493994<br />&minus;0.084589<br />0.3290</td><td>REDWideGamutRGB</td></tr>
 </table>
 
+<p class="var">wconv</p>
+<p>Indicates we want a full conversion for the white point.</p>
+<p>If set to <code>False</code>, chromatic adaptation will be used, so the
+white will stay white on the destination illuminant and colors will be adapted
+to implement a real illuminant change.
+This is generally what you want when converting between gamuts: the eye adapts
+to the new white and colors should be matched accordingly.</p>
+<p>If set to <code>True</code>, the chromatic adaptation is bypassed.
+The white from the source colorspace will appear with a tint if the target
+colorspace has a different white point.
+Use this if you want to emulate what a picture displayed with a monitor using
+the source illuminant looks like on a display using the target illuminant.
+This is also what you want when converting to and from XYZ for further
+operations in this colorspace.</p>
+
 <p class="var">cpuopt</p>
 <p>Limits the CPU instruction set.
 &minus;1: automatic (no limitation),
@@ -1978,7 +1995,8 @@ <h2><a id="changelog"></a>V) Changelog</h2>
 <li><code>matrix</code>: The <code>_ColorRange</code> frame property is now set when a matrix preset is used.</li>
 <li><code>transfer</code>: Added ACEScct transfer function.</li>
 <li><code>primaries</code>: Added DCI P3+ and Cinema Gamut presets.</li>
-<li>Changed the <code>configure</<code> options to compile with Clang.</li>
+<li><code>primaries</code>: Added <var>wconv</var> parameter for full conversion.</li>
+<li>Changed the <code>configure</code> options to compile with Clang.</li>
 <li>Updated datatypes in the examples.</li>
 </ul>
 

src/fmtc/Primaries_vs.cpp

@@ -105,8 +105,10 @@ Primaries::Primaries (const ::VSMap &in, ::VSMap &out, void *user_data_ptr, ::VS
 	init (_prim_d, *this, in, out, "rd", "gd", "bd", "wd");
 	assert (_prim_d.is_ready ());
 
+	const auto     conv_flag = (get_arg_int (in, out, "wconv", 0) != 0);
+
 	const fmtcl::Mat3 mat_conv =
-		fmtcl::PrimUtil::compute_conversion_matrix (_prim_s, _prim_d);
+		fmtcl::PrimUtil::compute_conversion_matrix (_prim_s, _prim_d, conv_flag);
 	_mat_main.insert3 (mat_conv);
 	_mat_main.clean3 (1);
 

src/fmtcavs/Primaries.h

@@ -62,6 +62,7 @@ class Primaries
 		Param_WD,
 		Param_PRIMS,
 		Param_PRIMD,
+		Param_WCONV,
 		Param_CPUOPT,
 
 		Param_NBR_ELT

src/fmtcavs/Primaries_avs.cpp

@@ -110,8 +110,10 @@ Primaries::Primaries (::IScriptEnvironment &env, const ::AVSValue &args)
 	init (_prim_d, env, args, Param_RD, Param_GD, Param_BD, Param_WD);
 	assert (_prim_d.is_ready ());
 
+	const auto     conv_flag = args [Param_WCONV].AsBool (false);
+
 	const fmtcl::Mat3 mat_conv =
-		fmtcl::PrimUtil::compute_conversion_matrix (_prim_s, _prim_d);
+		fmtcl::PrimUtil::compute_conversion_matrix (_prim_s, _prim_d, conv_flag);
 	_mat_main.insert3 (mat_conv);
 	_mat_main.clean3 (1);
 

src/fmtcl/PrimUtil.cpp

@@ -45,13 +45,20 @@ constexpr int	PrimUtil::_nbr_planes;
 
 
 
-Mat3	PrimUtil::compute_conversion_matrix (const RgbSystem &prim_s, const RgbSystem &prim_d)
+// conv_flag indicates we want a full conversion, not a chromatic adatpation
+Mat3	PrimUtil::compute_conversion_matrix (const RgbSystem &prim_s, const RgbSystem &prim_d, bool conv_flag)
 {
 	assert (prim_s.is_ready ());
 	assert (prim_d.is_ready ());
 
 	const Mat3     rgb2xyz = compute_rgb2xyz (prim_s);
 	const Mat3     xyz2rgb = compute_rgb2xyz (prim_d).invert ();
+
+	if (conv_flag)
+	{
+		return xyz2rgb * rgb2xyz;
+	}
+
 	const Mat3     adapt   = compute_chroma_adapt (prim_s, prim_d);
 
 	return xyz2rgb * adapt * rgb2xyz;

src/fmtcl/PrimUtil.h

@@ -44,7 +44,7 @@ class PrimUtil
 
 	static constexpr int _nbr_planes = RgbSystem::_nbr_planes;
 
-	static Mat3    compute_conversion_matrix (const RgbSystem &prim_s, const RgbSystem &prim_d);
+	static Mat3    compute_conversion_matrix (const RgbSystem &prim_s, const RgbSystem &prim_d, bool conv_flag);
 	static Mat3    compute_rgb2xyz (const RgbSystem &prim);
 	static Mat3    compute_chroma_adapt (const RgbSystem &prim_s, const RgbSystem &prim_d);
 	static Vec3    conv_xy_to_xyz (const RgbSystem::Vec2 &xy);

src/main-avs.cpp

@@ -60,7 +60,8 @@ const char * __stdcall	AvisynthPluginInit3 (::IScriptEnvironment *env_ptr, const
 	env_ptr->AddFunction (fmtcavs_PRIMARIES,
 		"c"      "[rs].+"   "[gs].+"   "[bs].+"    // 0
 		"[ws].+" "[rd].+"   "[gd].+"   "[bd].+"    // 4
-		"[wd].+" "[prims]s" "[primd]s" "[cpuopt]i" // 8
+		"[wd].+" "[prims]s" "[primd]s" "[wconv]b"  // 8
+		"[cpuopt]i"                                // 12
 		, &main_avs_create <fmtcavs::Primaries>, nullptr
 	);
 	env_ptr->AddFunction (fmtcavs_RESAMPLE,

src/main-vs.cpp

@@ -380,6 +380,7 @@ VS_EXTERNAL_API (void) VapourSynthPluginInit2 (::VSPlugin *plugin_ptr, const ::V
 		"wd:float[]:opt;"
 		"prims:data:opt;"
 		"primd:data:opt;"
+		"wconv:int:opt;"
 		"cpuopt:int:opt;"
 	,	"clip:vnode;"
 	,	&vsutl::Redirect <fmtc::Primaries>::create, nullptr, plugin_ptr