Texture.hpp

#ifndef TEXTURE_HPP
#define TEXTURE_HPP

#include <cstdint>
#include <vector>
#include "Shader.hpp"
#include "Config.hpp"

namespace Renderer
{
    /// @brief How out-of-range UVs are resolved.
    enum TextureAddressMode
    {
        WRAP,   ///< UVs wrap (tile).
        CLAMP,  ///< UVs are clamped to the [0,1) range.
        ZERO    ///< Out-of-range UVs return colour 0.
    };

    /// @brief Static 2D image used for diffuse / reflection / screen-space sampling.
    class Texture
    {
    public:
        int width;                          ///< Width in pixels.
        int height;                         ///< Height in pixels.
        uint16_t *data;                     ///< Pixel data; RGB565 unless `palette` is set, in which case it is paletted indices.
        bool hasAlpha;                      ///< When true, pixels equal to `alphaColor` are treated as transparent.
        uint16_t alphaColor;                ///< Colour key sampled as fully transparent.
        bool screenSpace;                   ///< When true, the texture is sampled in screen space rather than UV space.
        TextureAddressMode addressMode;     ///< UV addressing mode.
        uint16_t *palette;                  ///< Optional 256-entry palette; when non-null `data` is treated as indices.

        bool reflectionMap = false;         ///< When true, sampled via reflected view direction instead of UV.
        char* name = nullptr;               ///< Optional name for asset lookup.

        /// @brief Construct a texture.
        /// @param w Width in pixels.
        /// @param h Height in pixels.
        /// @param data Pixel data (caller-owned).
        /// @param hasAlpha Enable colour-key transparency.
        /// @param alphaColor Colour to treat as transparent when `hasAlpha` is true.
        /// @param screenSpace Sample in screen space instead of UV.
        /// @param addressMode UV addressing mode (WRAP/CLAMP/ZERO).
        /// @param palette Optional palette (caller-owned).
        Texture(int w, int h, uint16_t *data, bool hasAlpha = false, uint16_t alphaColor = 0, bool screenSpace = false, TextureAddressMode addressMode = WRAP, uint16_t *palette = nullptr);

        /// @brief Sample the texture at a UV coordinate.
        /// @param u Fixed-point U coordinate.
        /// @param v Fixed-point V coordinate.
        /// @return Sampled RGB565 colour.
        uint16_t getPixel(int u, int v);
    };

} // namespace Renderer

#endif // TEXTURE_HPP