PALETTE: added cvar to control the 6bit palette color behavior of the…

… RGBPalette format

this improves upon issue #519 to also allow to write such a 6bit palette as it is used in c&c

src/modules/core/GameConfig.h

@@ -69,6 +69,7 @@ constexpr const char *MetricFlavor = "metric_flavor";
 constexpr const char *MetricUUID = "metric_uuid";
 
 constexpr const char *VoxelPalette = "palette";
+constexpr const char *PalformatRGB6Bit = "palformat_rgb6bit";
 constexpr const char *VoxelCreatePalette = "voxformat_createpalette";
 constexpr const char *VoxformatMergequads = "voxformat_mergequads";
 constexpr const char *VoxformatReusevertices = "voxformat_reusevertices";

src/modules/io/FormatDescription.cpp

@@ -56,6 +56,10 @@ FormatDescription gimpPalette() {
 	return {"Gimp Palette", {"gpl"}, {}, FORMAT_FLAG_SAVE};
 }
 
+FormatDescription palPalette() {
+	return {"RGB Palette", {"pal"}, {}, FORMAT_FLAG_SAVE};
+}
+
 const FormatDescription *palettes() {
 	// clang-format: off
 	static thread_local FormatDescription desc[] = {
@@ -64,7 +68,7 @@ const FormatDescription *palettes() {
 		jascPalette(),
 		{"Adobe Swatch Exchange", {"ase"}, {"ASEF"}, FORMAT_FLAG_SAVE},
 		{"Photoshop Palette", {"aco", "8bco"}, {}, FORMAT_FLAG_SAVE},
-		{"RGB Palette", {"pal"}, {}, FORMAT_FLAG_SAVE},
+		palPalette(),
 		{"CSV Palette", {"csv"}, {}, FORMAT_FLAG_SAVE},
 		{"Paint.NET Palette", {"txt"}, {}, FORMAT_FLAG_SAVE},
 		{"Portable Network Graphics", {"png"}, {"\x89PNG"}, FORMAT_FLAG_SAVE},

src/modules/io/FormatDescription.h

@@ -122,6 +122,7 @@ const FormatDescription* palettes();
 FormatDescription png();
 FormatDescription jascPalette();
 FormatDescription gimpPalette();
+FormatDescription palPalette();
 
 } // namespace format
 

src/modules/palette/private/RGBPalette.cpp

@@ -5,6 +5,7 @@
 #include "RGBPalette.h"
 #include "core/Log.h"
 #include "core/StringUtil.h"
+#include "core/Var.h"
 
 namespace palette {
 
@@ -36,7 +37,7 @@ bool RGBPalette::load(const core::String &filename, io::SeekableReadStream &stre
 		maxColor = core_max(rgba.b, maxColor);
 	}
 	const bool is6Bit = maxColor <= 63;
-	if (is6Bit) {
+	if (is6Bit && core::Var::getSafe(cfg::PalformatRGB6Bit)->boolVal()) {
 		const float scale = (255.0f / 63.0f);
 		for (int i = 0; i < PaletteMaxColors; ++i) {
 			core::RGBA rgba = palette.color(i);
@@ -51,11 +52,19 @@ bool RGBPalette::load(const core::String &filename, io::SeekableReadStream &stre
 }
 
 bool RGBPalette::save(const palette::Palette &palette, const core::String &filename, io::SeekableWriteStream &stream) {
+	const bool to6Bit = core::Var::getSafe(cfg::PalformatRGB6Bit)->boolVal();
+	const float scale = (255.0f / 63.0f);
 	for (size_t i = 0; i < palette.size(); ++i) {
-		const core::RGBA color = palette.color(i);
-		stream.writeUInt8(color.r);
-		stream.writeUInt8(color.g);
-		stream.writeUInt8(color.b);
+		core::RGBA color = palette.color(i);
+		if (to6Bit) {
+			stream.writeUInt8((uint8_t)((float)color.r / scale));
+			stream.writeUInt8((uint8_t)((float)color.g / scale));
+			stream.writeUInt8((uint8_t)((float)color.b / scale));
+		} else {
+			stream.writeUInt8(color.r);
+			stream.writeUInt8(color.g);
+			stream.writeUInt8(color.b);
+		}
 	}
 	return true;
 }

src/modules/voxelformat/FormatConfig.cpp

@@ -109,6 +109,10 @@ bool FormatConfig::init() {
 				   "Import the image as volume for both sides", core::Var::boolValidator);
 	core::Var::get(cfg::VoxformatImageImportType, "0", core::CV_NOPERSIST, "0 = plane, 1 = heightmap, 2 = volume",
 				   core::Var::minMaxValidator<0, 2>);
+
+	core::Var::get(cfg::PalformatRGB6Bit, "false", core::CV_NOPERSIST, "Use 6 bit color values for the palette (0-63) - used e.g. in C&C pal files",
+				   core::Var::boolValidator);
+
 	return true;
 }
 

src/tools/voxedit/modules/voxedit-ui/FileDialogOptions.cpp

@@ -18,6 +18,10 @@ void fileDialogOptions(video::OpenFileMode mode, const io::FormatDescription *de
 		return;
 	}
 
+	if (*desc == io::format::palPalette()) {
+		ImGui::CheckboxVar(_("6 bit color values"), cfg::PalformatRGB6Bit);
+	}
+
 	const bool forceApplyOptions = (desc->flags & FORMAT_FLAG_ALL) == FORMAT_FLAG_ALL;
 	const bool meshFormat = voxelformat::isMeshFormat(*desc);
 	if (forceApplyOptions || meshFormat) {