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Vibe-HD-2D/engine/include/hd2d/Texture.h
Gabrieal Jimmy 2c99305fb0 init
2026-10-02 12:42:00 -05:00

69 lines
2.3 KiB
C++

#pragma once
#include "hd2d/GL.h"
#include <glm/glm.hpp>
#include <string>
#include <vector>
namespace hd2d {
struct Image {
int width = 0, height = 0;
std::vector<unsigned char> rgba; // row 0 = bottom (GL convention)
};
// Loads an RGBA8 image flipped to GL orientation. Colors of fully transparent
// pixels are replaced with their nearest opaque neighbour so that filtering
// never bleeds dark fringes into sprite edges.
bool loadImage(const std::string& path, Image& out);
// Decodes PNG bytes from memory. glTF images use flipY = false (their UV
// origin is top-left, which matches GL when rows are uploaded unflipped).
bool decodeImage(const unsigned char* data, size_t size, Image& out, bool flipY);
// sRGB pixel-art texture. Sampled with "sharp bilinear" in shaders, so it uses
// linear filtering with mipmaps rather than GL_NEAREST.
class Texture {
public:
Texture() = default;
Texture(const Texture&) = delete;
Texture& operator=(const Texture&) = delete;
Texture(Texture&& o) noexcept { *this = std::move(o); }
Texture& operator=(Texture&& o) noexcept;
~Texture();
bool load(const std::string& path, bool repeat = false);
bool create(const Image& image, bool repeat = false, float anisotropy = 1.0f);
void bind(GLuint unit) const { glBindTextureUnit(unit, id_); }
GLuint id() const { return id_; }
glm::ivec2 size() const { return {width_, height_}; }
// UV-space rectangle (minX, minY, maxX, maxY) of pixels with alpha >= 128.
// Billboards use minY to plant the visible feet on the ground.
glm::vec4 opaqueBounds() const { return opaqueBounds_; }
private:
GLuint id_ = 0;
int width_ = 0, height_ = 0;
glm::vec4 opaqueBounds_{0, 0, 1, 1};
};
// 2D array of equally sized sRGB layers (terrain materials).
class TextureArray {
public:
TextureArray() = default;
TextureArray(const TextureArray&) = delete;
TextureArray& operator=(const TextureArray&) = delete;
~TextureArray();
bool load(const std::vector<std::string>& paths);
void bind(GLuint unit) const { glBindTextureUnit(unit, id_); }
glm::ivec2 size() const { return {width_, height_}; }
int layers() const { return layers_; }
private:
GLuint id_ = 0;
int width_ = 0, height_ = 0, layers_ = 0;
};
} // namespace hd2d