LibGfx+icc: Add profile connection space printing

This is a bit messy: The spec says that PCSXYZ and PCSLAB are the only
valid profile connection spaces -- except for DeviceLink profles, where
all data color spaces are valid.

So this uses the existing ColorSpace enum for profile connection spaces
instead of adding a dedicated enum, to not duplicate all the color space
parsing and printing code.  That matches what the spec does, too.
This saves about 100 lines of code, at the expense of less type
safety -- but further down the line we probably want to be able to
compare data color spaces and profile connection spaces, so the type
safety would likely get in the way then. (But if not, we can change
things around once we get to that point.)

2 files changed, 49 insertions, 10 deletions

diff --git a/Userland/Libraries/LibGfx/ICCProfile.cpp b/Userland/Libraries/LibGfx/ICCProfile.cpp
index 76963281cb..fd85534790 100644
--- a/Userland/Libraries/LibGfx/ICCProfile.cpp
+++ b/Userland/Libraries/LibGfx/ICCProfile.cpp
@@ -78,7 +78,7 @@ struct ICCHeader {
 
     BigEndian<DeviceClass> profile_device_class;
     BigEndian<ColorSpace> data_color_space;
-    BigEndian<u32> pcs; // "Profile Connection Space"
+    BigEndian<ColorSpace> profile_connection_space; // "PCS" in the spec.
 
     DateTimeNumber profile_creation_time;
 
@@ -126,10 +126,10 @@ ErrorOr<DeviceClass> parse_device_class(ICCHeader const& header)
     return Error::from_string_literal("ICC::Profile: Invalid device class");
 }
 
-ErrorOr<ColorSpace> parse_data_color_space(ICCHeader const& header)
+ErrorOr<ColorSpace> parse_color_space(ColorSpace color_space)
 {
-    // ICC v4, 7.2.6 Data colour space field
-    switch (header.data_color_space) {
+    // ICC v4, Table 19 — Data colour space signatures
+    switch (color_space) {
     case ColorSpace::nCIEXYZ:
     case ColorSpace::CIELAB:
     case ColorSpace::CIELUV:
@@ -155,9 +155,27 @@ ErrorOr<ColorSpace> parse_data_color_space(ICCHeader const& header)
     case ColorSpace::ThirteenColor:
     case ColorSpace::FourteenColor:
     case ColorSpace::FifteenColor:
-        return header.data_color_space;
+        return color_space;
     }
-    return Error::from_string_literal("ICC::Profile: Invalid data color space");
+    return Error::from_string_literal("ICC::Profile: Invalid color space");
+}
+
+ErrorOr<ColorSpace> parse_data_color_space(ICCHeader const& header)
+{
+    // ICC v4, 7.2.6 Data colour space field
+    return parse_color_space(header.data_color_space);
+}
+
+ErrorOr<ColorSpace> parse_connection_space(ICCHeader const& header)
+{
+    // ICC v4, 7.2.7 PCS field
+    //         and Annex D
+    auto space = TRY(parse_color_space(header.profile_connection_space));
+
+    if (header.profile_device_class != DeviceClass::DeviceLink && (space != ColorSpace::PCSXYZ && space != ColorSpace::PCSLAB))
+        return Error::from_string_literal("ICC::Profile: Invalid profile connection space: Non-PCS space on non-DeviceLink profile");
+
+    return space;
 }
 
 ErrorOr<RenderingIntent> parse_rendering_intent(ICCHeader const& header)
@@ -212,7 +230,7 @@ StringView device_class_name(DeviceClass device_class)
     VERIFY_NOT_REACHED();
 }
 
-StringView color_space_name(ColorSpace color_space)
+StringView data_color_space_name(ColorSpace color_space)
 {
     switch (color_space) {
     case ColorSpace::nCIEXYZ:
@@ -269,6 +287,18 @@ StringView color_space_name(ColorSpace color_space)
     VERIFY_NOT_REACHED();
 }
 
+StringView profile_connection_space_name(ColorSpace color_space)
+{
+    switch (color_space) {
+    case ColorSpace::PCSXYZ:
+        return "PCSXYZ"sv;
+    case ColorSpace::PCSLAB:
+        return "PCSLAB"sv;
+    default:
+        return data_color_space_name(color_space);
+    }
+}
+
 StringView rendering_intent_name(RenderingIntent rendering_intent)
 {
     switch (rendering_intent) {
@@ -303,6 +333,7 @@ ErrorOr<NonnullRefPtr<Profile>> Profile::try_load_from_externally_owned_memory(R
     profile->m_version = TRY(parse_version(header));
     profile->m_device_class = TRY(parse_device_class(header));
     profile->m_data_color_space = TRY(parse_data_color_space(header));
+    profile->m_connection_space = TRY(parse_connection_space(header));
     profile->m_creation_timestamp = TRY(parse_creation_date_time(header));
     profile->m_flags = Flags { header.profile_flags };
     profile->m_rendering_intent = TRY(parse_rendering_intent(header));
diff --git a/Userland/Libraries/LibGfx/ICCProfile.h b/Userland/Libraries/LibGfx/ICCProfile.h
index 11287bd375..aa35616c0c 100644
--- a/Userland/Libraries/LibGfx/ICCProfile.h
+++ b/Userland/Libraries/LibGfx/ICCProfile.h
@@ -47,8 +47,10 @@ StringView device_class_name(DeviceClass);
 
 // ICC v4, 7.2.6 Data colour space field, Table 19 — Data colour space signatures
 enum class ColorSpace : u32 {
-    nCIEXYZ = 0x58595A20,       // 'XYZ '
-    CIELAB = 0x4C616220,        // 'Lab '
+    nCIEXYZ = 0x58595A20,       // 'XYZ ', used in data color spaces.
+    PCSXYZ = nCIEXYZ,           // Used in profile connection space instead.
+    CIELAB = 0x4C616220,        // 'Lab ', used in data color spaces.
+    PCSLAB = CIELAB,            // Used in profile connection space instead.
     CIELUV = 0x4C757620,        // 'Luv '
     YCbCr = 0x59436272,         // 'YCbr'
     CIEYxy = 0x59787920,        // 'Yxy '
@@ -73,7 +75,8 @@ enum class ColorSpace : u32 {
     FourteenColor = 0x45434C52, // 'ECLR'
     FifteenColor = 0x46434C52,  // 'FCLR'
 };
-StringView color_space_name(ColorSpace);
+StringView data_color_space_name(ColorSpace);
+StringView profile_connection_space_name(ColorSpace);
 
 // ICC v4, 7.2.15 Rendering intent field
 enum class RenderingIntent {
@@ -119,6 +122,10 @@ public:
     Version version() const { return m_version; }
     DeviceClass device_class() const { return m_device_class; }
     ColorSpace data_color_space() const { return m_data_color_space; }
+
+    // For non-DeviceLink profiles, always PCSXYZ or PCSLAB.
+    ColorSpace connection_space() const { return m_connection_space; }
+
     time_t creation_timestamp() const { return m_creation_timestamp; }
     Flags flags() const { return m_flags; }
     RenderingIntent rendering_intent() const { return m_rendering_intent; }
@@ -127,6 +134,7 @@ private:
     Version m_version;
     DeviceClass m_device_class;
     ColorSpace m_data_color_space;
+    ColorSpace m_connection_space;
     time_t m_creation_timestamp;
     Flags m_flags;
     RenderingIntent m_rendering_intent;