Add new ImageId struct

src/openrct2/drawing/Drawing.cpp

@@ -15,6 +15,7 @@
 #include "../core/Guard.hpp"
 #include "../object/Object.h"
 #include "../platform/platform.h"
+#include "../sprites.h"
 #include "../util/Util.h"
 #include "../world/Water.h"
 
@@ -465,6 +466,32 @@ const translucent_window_palette TranslucentWindowPalettes[COLOUR_COUNT] = {
 };
 // clang-format on
 
+ImageCatalogue ImageId::GetCatalogue() const
+{
+    auto index = GetIndex();
+    if (index == SPR_TEMP)
+    {
+        return ImageCatalogue::TEMPORARY;
+    }
+    else if (index < SPR_RCTC_G1_END)
+    {
+        return ImageCatalogue::G1;
+    }
+    else if (index < SPR_G2_END)
+    {
+        return ImageCatalogue::G2;
+    }
+    else if (index < SPR_CSG_END)
+    {
+        return ImageCatalogue::CSG;
+    }
+    else if (index < SPR_IMAGE_LIST_END)
+    {
+        return ImageCatalogue::OBJECT;
+    }
+    return ImageCatalogue::UNKNOWN;
+}
+
 void (*mask_fn)(
     int32_t width, int32_t height, const uint8_t* RESTRICT maskSrc, const uint8_t* RESTRICT colourSrc, uint8_t* RESTRICT dst,
     int32_t maskWrap, int32_t colourWrap, int32_t dstWrap)

src/openrct2/drawing/Drawing.h

@@ -230,6 +230,92 @@ struct rct_size16
     int16_t height;
 };
 
+enum class ImageCatalogue
+{
+    UNKNOWN,
+    G1,
+    G2,
+    CSG,
+    OBJECT,
+    TEMPORARY,
+};
+
+/**
+ * Represents a specific image from a catalogue such as G1, G2, CSG etc. with remap
+ * colours and flags.
+ *
+ * This is currently all stored as a single 32-bit integer, but will allow easy
+ * extension to 64-bits or higher so that more images can be used.
+ */
+struct ImageId
+{
+private:
+    // clang-format off
+    static constexpr uint32_t MASK_INDEX       = 0b00000000000001111111111111111111;
+    static constexpr uint32_t MASK_PRIMARY     = 0b00000000111110000000000000000000;
+    static constexpr uint32_t MASK_SECONDARY   = 0b00011111000000000000000000000000;
+    static constexpr uint32_t FLAG_PRIMARY     = 0b00100000000000000000000000000000;
+    static constexpr uint32_t FLAG_TRANSPARENT = 0b01000000000000000000000000000000;
+    static constexpr uint32_t FLAG_SECONDARY   = 0b10000000000000000000000000000000;
+    static constexpr uint32_t SHIFT_PRIMARY    = 19;
+    static constexpr uint32_t SHIFT_SECONDARY  = 24;
+    // clang-format on
+
+    uint32_t _value;
+
+public:
+    ImageId(uint32_t index)
+        : _value(index & MASK_INDEX)
+    {
+    }
+
+    ImageId(uint32_t index, colour_t primaryColour)
+        : ImageId(ImageId(index).WithPrimary(primaryColour))
+    {
+    }
+
+    ImageId(uint32_t index, colour_t primaryColour, colour_t secondaryColour)
+        : ImageId(ImageId(index).WithPrimary(primaryColour).WithSecondary(secondaryColour))
+    {
+    }
+
+    uint32_t ToUInt32() const
+    {
+        return _value;
+    }
+
+    uint32_t GetIndex() const
+    {
+        return _value & MASK_INDEX;
+    }
+
+    colour_t GetPrimary() const
+    {
+        return _value & MASK_PRIMARY;
+    }
+
+    colour_t GetSecondary() const
+    {
+        return _value & MASK_SECONDARY;
+    }
+
+    ImageCatalogue GetCatalogue() const;
+
+    ImageId WithPrimary(colour_t colour)
+    {
+        ImageId result = *this;
+        result._value = (_value & ~MASK_PRIMARY) | ((colour << SHIFT_PRIMARY) & MASK_PRIMARY) | FLAG_PRIMARY;
+        return result;
+    }
+
+    ImageId WithSecondary(colour_t colour)
+    {
+        ImageId result = *this;
+        result._value = (_value & ~MASK_SECONDARY) | ((colour << SHIFT_SECONDARY) & MASK_SECONDARY) | FLAG_SECONDARY;
+        return result;
+    }
+};
+
 #define SPRITE_ID_PALETTE_COLOUR_1(colourId) (IMAGE_TYPE_REMAP | ((colourId) << 19))
 #define SPRITE_ID_PALETTE_COLOUR_2(primaryId, secondaryId)                                                                     \
     (IMAGE_TYPE_REMAP_2_PLUS | IMAGE_TYPE_REMAP | (((primaryId) << 19) | ((secondaryId) << 24)))