image.h

/**************************************************************************/
/*  image.h                                                               */
/**************************************************************************/
/*                         This file is part of:                          */
/*                             GODOT ENGINE                               */
/*                        https://godotengine.org                         */
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/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
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#pragma once

#include "core/io/resource.h"
#include "core/math/color.h"

/**
 * Image storage class. This is used to store an image in user memory, as well as
 * providing some basic methods for image manipulation.
 * Images can be loaded from a file, or registered into the Render object as textures.
 */

class Image;

// Function pointer prototypes.

typedef Error (*SavePNGFunc)(const String &p_path, const Ref<Image> &p_img);
typedef Vector<uint8_t> (*SavePNGBufferFunc)(const Ref<Image> &p_img);

typedef Error (*SaveJPGFunc)(const String &p_path, const Ref<Image> &p_img, float p_quality);
typedef Vector<uint8_t> (*SaveJPGBufferFunc)(const Ref<Image> &p_img, float p_quality);

typedef Ref<Image> (*ImageMemLoadFunc)(const uint8_t *p_data, int p_size);
typedef Ref<Image> (*ScalableImageMemLoadFunc)(const uint8_t *p_data, int p_size, float p_scale);

typedef Error (*SaveWebPFunc)(const String &p_path, const Ref<Image> &p_img, const bool p_lossy, const float p_quality);
typedef Vector<uint8_t> (*SaveWebPBufferFunc)(const Ref<Image> &p_img, const bool p_lossy, const float p_quality);

typedef Error (*SaveEXRFunc)(const String &p_path, const Ref<Image> &p_img, bool p_grayscale);
typedef Vector<uint8_t> (*SaveEXRBufferFunc)(const Ref<Image> &p_img, bool p_grayscale);

typedef Error (*SaveDDSFunc)(const String &p_path, const Ref<Image> &p_img);
typedef Vector<uint8_t> (*SaveDDSBufferFunc)(const Ref<Image> &p_img);

class Image : public Resource {
	GDCLASS(Image, Resource);

public:
	enum {
		MAX_WIDTH = (1 << 24), // Force a limit somehow.
		MAX_HEIGHT = (1 << 24), // Force a limit somehow.
		MAX_PIXELS = 268435456 // 16384 ^ 2
	};

	enum Format : int32_t {
		FORMAT_L8, // Luminance
		FORMAT_LA8, // Luminance-Alpha
		FORMAT_R8,
		FORMAT_RG8,
		FORMAT_RGB8,
		FORMAT_RGBA8,
		FORMAT_RGBA4444,
		FORMAT_RGB565,
		FORMAT_RF, // Float
		FORMAT_RGF,
		FORMAT_RGBF,
		FORMAT_RGBAF,
		FORMAT_RH, // Half
		FORMAT_RGH,
		FORMAT_RGBH,
		FORMAT_RGBAH,
		FORMAT_RGBE9995,
		FORMAT_DXT1, // BC1
		FORMAT_DXT3, // BC2
		FORMAT_DXT5, // BC3
		FORMAT_RGTC_R, // BC4
		FORMAT_RGTC_RG, // BC5
		FORMAT_BPTC_RGBA, // BC7
		FORMAT_BPTC_RGBF, // BC6 Signed
		FORMAT_BPTC_RGBFU, // BC6 Unsigned
		FORMAT_ETC, // ETC1
		FORMAT_ETC2_R11,
		FORMAT_ETC2_R11S, // Signed, NOT srgb.
		FORMAT_ETC2_RG11,
		FORMAT_ETC2_RG11S, // Signed, NOT srgb.
		FORMAT_ETC2_RGB8,
		FORMAT_ETC2_RGBA8,
		FORMAT_ETC2_RGB8A1,
		FORMAT_ETC2_RA_AS_RG, // ETC2 RGBA with a RA-RG swizzle for normal maps.
		FORMAT_DXT5_RA_AS_RG, // BC3 with a RA-RG swizzle for normal maps.
		FORMAT_ASTC_4x4,
		FORMAT_ASTC_4x4_HDR,
		FORMAT_ASTC_8x8,
		FORMAT_ASTC_8x8_HDR,
		FORMAT_MAX
	};

	static const char *format_names[FORMAT_MAX];

	enum Interpolation {
		INTERPOLATE_NEAREST,
		INTERPOLATE_BILINEAR,
		INTERPOLATE_CUBIC,
		INTERPOLATE_TRILINEAR,
		INTERPOLATE_LANCZOS,
		// INTERPOLATE_TRICUBIC,
		// INTERPOLATE_GAUSS
	};

	// Used for obtaining optimal compression quality.
	enum UsedChannels {
		USED_CHANNELS_L,
		USED_CHANNELS_LA,
		USED_CHANNELS_R,
		USED_CHANNELS_RG,
		USED_CHANNELS_RGB,
		USED_CHANNELS_RGBA,
	};

	// ASTC supports block formats other than 4x4.
	enum ASTCFormat {
		ASTC_FORMAT_4x4,
		ASTC_FORMAT_8x8,
	};

	enum RoughnessChannel {
		ROUGHNESS_CHANNEL_R,
		ROUGHNESS_CHANNEL_G,
		ROUGHNESS_CHANNEL_B,
		ROUGHNESS_CHANNEL_A,
		ROUGHNESS_CHANNEL_L,
	};

	enum Image3DValidateError {
		VALIDATE_3D_OK,
		VALIDATE_3D_ERR_IMAGE_EMPTY,
		VALIDATE_3D_ERR_MISSING_IMAGES,
		VALIDATE_3D_ERR_EXTRA_IMAGES,
		VALIDATE_3D_ERR_IMAGE_SIZE_MISMATCH,
		VALIDATE_3D_ERR_IMAGE_FORMAT_MISMATCH,
		VALIDATE_3D_ERR_IMAGE_HAS_MIPMAPS,
	};

	enum CompressMode {
		COMPRESS_S3TC,
		COMPRESS_ETC,
		COMPRESS_ETC2,
		COMPRESS_BPTC,
		COMPRESS_ASTC,
		COMPRESS_MAX,
	};

	enum CompressSource {
		COMPRESS_SOURCE_GENERIC,
		COMPRESS_SOURCE_SRGB,
		COMPRESS_SOURCE_NORMAL,
		COMPRESS_SOURCE_MAX,
	};

	enum AlphaMode {
		ALPHA_NONE,
		ALPHA_BIT,
		ALPHA_BLEND
	};

	struct BasisUniversalPackerParams {
		int uastc_level = 0;
		float rdo_quality_loss = 0;
	};

	// External saver function pointers.

	static inline SavePNGFunc save_png_func = nullptr;
	static inline SaveJPGFunc save_jpg_func = nullptr;
	static inline SaveEXRFunc save_exr_func = nullptr;
	static inline SaveWebPFunc save_webp_func = nullptr;
	static inline SaveDDSFunc save_dds_func = nullptr;
	static inline SavePNGBufferFunc save_png_buffer_func = nullptr;
	static inline SaveEXRBufferFunc save_exr_buffer_func = nullptr;
	static inline SaveJPGBufferFunc save_jpg_buffer_func = nullptr;
	static inline SaveWebPBufferFunc save_webp_buffer_func = nullptr;
	static inline SaveDDSBufferFunc save_dds_buffer_func = nullptr;

	// External loader function pointers.

	static inline ImageMemLoadFunc _png_mem_loader_func = nullptr;
	static inline ImageMemLoadFunc _png_mem_unpacker_func = nullptr;
	static inline ImageMemLoadFunc _jpg_mem_loader_func = nullptr;
	static inline ImageMemLoadFunc _webp_mem_loader_func = nullptr;
	static inline ImageMemLoadFunc _tga_mem_loader_func = nullptr;
	static inline ImageMemLoadFunc _bmp_mem_loader_func = nullptr;
	static inline ScalableImageMemLoadFunc _svg_scalable_mem_loader_func = nullptr;
	static inline ImageMemLoadFunc _ktx_mem_loader_func = nullptr;
	static inline ImageMemLoadFunc _dds_mem_loader_func = nullptr;

	// External VRAM compression function pointers.

	static void (*_image_compress_bc_func)(Image *, UsedChannels p_channels);
	static void (*_image_compress_bptc_func)(Image *, UsedChannels p_channels);
	static void (*_image_compress_etc1_func)(Image *);
	static void (*_image_compress_etc2_func)(Image *, UsedChannels p_channels);
	static void (*_image_compress_astc_func)(Image *, ASTCFormat p_format);

	static Error (*_image_compress_bptc_rd_func)(Image *, UsedChannels p_channels);
	static Error (*_image_compress_bc_rd_func)(Image *, UsedChannels p_channels);

	// External VRAM decompression function pointers.

	static void (*_image_decompress_bc)(Image *);
	static void (*_image_decompress_bptc)(Image *);
	static void (*_image_decompress_etc1)(Image *);
	static void (*_image_decompress_etc2)(Image *);
	static void (*_image_decompress_astc)(Image *);

	// External packer function pointers.

	static Vector<uint8_t> (*webp_lossy_packer)(const Ref<Image> &p_image, float p_quality);
	static Vector<uint8_t> (*webp_lossless_packer)(const Ref<Image> &p_image);
	static Vector<uint8_t> (*png_packer)(const Ref<Image> &p_image);
	static Vector<uint8_t> (*basis_universal_packer)(const Ref<Image> &p_image, UsedChannels p_channels, const BasisUniversalPackerParams &p_basisu_params);

	static Ref<Image> (*webp_unpacker)(const Vector<uint8_t> &p_buffer);
	static Ref<Image> (*png_unpacker)(const Vector<uint8_t> &p_buffer);
	static Ref<Image> (*basis_universal_unpacker)(const Vector<uint8_t> &p_buffer);
	static Ref<Image> (*basis_universal_unpacker_ptr)(const uint8_t *p_data, int p_size);

protected:
	virtual Ref<Resource> _duplicate(const DuplicateParams &p_params) const override;

	static void _bind_methods();

private:
	Format format = FORMAT_L8;
	Vector<uint8_t> data;
	int width = 0;
	int height = 0;
	bool mipmaps = false;

	void _copy_internals_from(const Image &p_image);

	_FORCE_INLINE_ Color _get_color_at_ofs(const uint8_t *ptr, uint32_t ofs) const;
	_FORCE_INLINE_ void _set_color_at_ofs(uint8_t *ptr, uint32_t ofs, const Color &p_color);

	_FORCE_INLINE_ void _get_mipmap_offset_and_size(int p_mipmap, int64_t &r_offset, int &r_width, int &r_height) const; // Get where the mipmap begins in data.

	static int64_t _get_dst_image_size(int p_width, int p_height, Format p_format, int &r_mipmaps, int p_mipmaps = -1, int *r_mm_width = nullptr, int *r_mm_height = nullptr);

	_FORCE_INLINE_ void _get_clipped_src_and_dest_rects(const Ref<Image> &p_src, const Rect2i &p_src_rect, const Point2i &p_dest, Rect2i &r_clipped_src_rect, Rect2i &r_clipped_dest_rect) const;

	_FORCE_INLINE_ void _put_pixelb(int p_x, int p_y, uint32_t p_pixel_size, uint8_t *p_data, const uint8_t *p_pixel);
	_FORCE_INLINE_ void _get_pixelb(int p_x, int p_y, uint32_t p_pixel_size, const uint8_t *p_data, uint8_t *p_pixel);

	_FORCE_INLINE_ void _repeat_pixel_over_subsequent_memory(uint8_t *p_pixel, int p_pixel_size, int p_count);

	void _set_data(const Dictionary &p_data);
	Dictionary _get_data() const;

	Error _load_from_buffer(const Vector<uint8_t> &p_array, ImageMemLoadFunc p_loader);

	_FORCE_INLINE_ void _generate_mipmap_from_format(Image::Format p_format, const uint8_t *p_src, uint8_t *p_dst, uint32_t p_width, uint32_t p_height, bool p_renormalize = false);

	static void average_4_uint8(uint8_t &p_out, const uint8_t &p_a, const uint8_t &p_b, const uint8_t &p_c, const uint8_t &p_d);
	static void average_4_float(float &p_out, const float &p_a, const float &p_b, const float &p_c, const float &p_d);
	static void average_4_half(uint16_t &p_out, const uint16_t &p_a, const uint16_t &p_b, const uint16_t &p_c, const uint16_t &p_d);
	static void average_4_rgbe9995(uint32_t &p_out, const uint32_t &p_a, const uint32_t &p_b, const uint32_t &p_c, const uint32_t &p_d);
	static void renormalize_uint8(uint8_t *p_rgb);
	static void renormalize_float(float *p_rgb);
	static void renormalize_half(uint16_t *p_rgb);
	static void renormalize_rgbe9995(uint32_t *p_rgb);

public:
	int get_width() const;
	int get_height() const;
	Size2i get_size() const;
	bool has_mipmaps() const;
	int get_mipmap_count() const;

	// Convert the image to another format, conversion only to raw byte format.
	void convert(Format p_new_format);

	Format get_format() const;

	// Get where the mipmap begins in data.
	int64_t get_mipmap_offset(int p_mipmap) const;
	void get_mipmap_offset_and_size(int p_mipmap, int64_t &r_ofs, int64_t &r_size) const;
	void get_mipmap_offset_size_and_dimensions(int p_mipmap, int64_t &r_ofs, int64_t &r_size, int &w, int &h) const;

	static Image3DValidateError validate_3d_image(Format p_format, int p_width, int p_height, int p_depth, bool p_mipmaps, const Vector<Ref<Image>> &p_images);
	static String get_3d_image_validation_error_text(Image3DValidateError p_error);

	// Resize the image, using the preferred interpolation method.
	void resize_to_po2(bool p_square = false, Interpolation p_interpolation = INTERPOLATE_BILINEAR);
	void resize(int p_width, int p_height, Interpolation p_interpolation = INTERPOLATE_BILINEAR);
	void shrink_x2();
	bool is_size_po2() const;

	// Crop the image to a specific size, if larger, then the image is filled by black.
	void crop_from_point(int p_x, int p_y, int p_width, int p_height);
	void crop(int p_width, int p_height);

	void rotate_90(ClockDirection p_direction);
	void rotate_180();

	void flip_x();
	void flip_y();

	// Generate a mipmap chain of an image (creates an image 1/4 the size, with averaging of 4->1).
	Error generate_mipmaps(bool p_renormalize = false);

	Error generate_mipmap_roughness(RoughnessChannel p_roughness_channel, const Ref<Image> &p_normal_map);

	void clear_mipmaps();
	void normalize();

	// Creates new internal image data of a given size and format. Current image will be lost.
	void initialize_data(int p_width, int p_height, bool p_use_mipmaps, Format p_format);
	void initialize_data(int p_width, int p_height, bool p_use_mipmaps, Format p_format, const Vector<uint8_t> &p_data);
	void initialize_data(const char **p_xpm);

	// Returns true when the image is empty (0,0) in size.
	bool is_empty() const;

	Vector<uint8_t> get_data() const;

	Error load(const String &p_path);
	static Ref<Image> load_from_file(const String &p_path);
	Error save_png(const String &p_path) const;
	Error save_jpg(const String &p_path, float p_quality = 0.75) const;
	Error save_dds(const String &p_path) const;
	Vector<uint8_t> save_png_to_buffer() const;
	Vector<uint8_t> save_jpg_to_buffer(float p_quality = 0.75) const;
	Vector<uint8_t> save_exr_to_buffer(bool p_grayscale = false) const;
	Vector<uint8_t> save_dds_to_buffer() const;
	Error save_exr(const String &p_path, bool p_grayscale = false) const;
	Error save_webp(const String &p_path, const bool p_lossy = false, const float p_quality = 0.75f) const;
	Vector<uint8_t> save_webp_to_buffer(const bool p_lossy = false, const float p_quality = 0.75f) const;

	static Ref<Image> create_empty(int p_width, int p_height, bool p_use_mipmaps, Format p_format);
	static Ref<Image> create_from_data(int p_width, int p_height, bool p_use_mipmaps, Format p_format, const Vector<uint8_t> &p_data);
	void set_data(int p_width, int p_height, bool p_use_mipmaps, Format p_format, const Vector<uint8_t> &p_data);

	Image() = default; // Create an empty image.
	Image(int p_width, int p_height, bool p_use_mipmaps, Format p_format); // Create an empty image of a specific size and format.
	Image(int p_width, int p_height, bool p_mipmaps, Format p_format, const Vector<uint8_t> &p_data); // Import an image of a specific size and format from a byte vector.
	Image(const uint8_t *p_mem_png_jpg, int p_len = -1); // Import either a png or jpg from a pointer.
	Image(const char **p_xpm); // Import an XPM image.

	~Image() {}

	AlphaMode detect_alpha() const;
	bool is_invisible() const;

	static int get_format_pixel_size(Format p_format);
	static int get_format_pixel_rshift(Format p_format);
	static int get_format_block_size(Format p_format);
	static void get_format_min_pixel_size(Format p_format, int &r_w, int &r_h);

	static int64_t get_image_data_size(int p_width, int p_height, Format p_format, bool p_mipmaps = false);
	static int get_image_required_mipmaps(int p_width, int p_height, Format p_format);
	static Size2i get_image_mipmap_size(int p_width, int p_height, Format p_format, int p_mipmap);
	static int64_t get_image_mipmap_offset(int p_width, int p_height, Format p_format, int p_mipmap);
	static int64_t get_image_mipmap_offset_and_dimensions(int p_width, int p_height, Format p_format, int p_mipmap, int &r_w, int &r_h);

	Error compress(CompressMode p_mode, CompressSource p_source = COMPRESS_SOURCE_GENERIC, ASTCFormat p_astc_format = ASTC_FORMAT_4x4);
	Error compress_from_channels(CompressMode p_mode, UsedChannels p_channels, ASTCFormat p_astc_format = ASTC_FORMAT_4x4);
	Error decompress();
	bool is_compressed() const;
	static bool is_format_compressed(Format p_format);

	static bool can_decompress(const String &p_format_tag);

	void fix_alpha_edges();
	void premultiply_alpha();
	void srgb_to_linear();
	void linear_to_srgb();
	void normal_map_to_xy();
	Ref<Image> rgbe_to_srgb();
	Ref<Image> get_image_from_mipmap(int p_mipmap) const;
	void bump_map_to_normal_map(float bump_scale = 1.0);

	bool detect_signed(bool p_include_mips = true) const;

	void blit_rect(const Ref<Image> &p_src, const Rect2i &p_src_rect, const Point2i &p_dest);
	void blit_rect_mask(const Ref<Image> &p_src, const Ref<Image> &p_mask, const Rect2i &p_src_rect, const Point2i &p_dest);
	void blend_rect(const Ref<Image> &p_src, const Rect2i &p_src_rect, const Point2i &p_dest);
	void blend_rect_mask(const Ref<Image> &p_src, const Ref<Image> &p_mask, const Rect2i &p_src_rect, const Point2i &p_dest);
	void fill(const Color &p_color);
	void fill_rect(const Rect2i &p_rect, const Color &p_color);

	Rect2i get_used_rect() const;
	Ref<Image> get_region(const Rect2i &p_area) const;

	static String get_format_name(Format p_format);
	static uint32_t get_format_component_mask(Format p_format);

	Error load_png_from_buffer(const Vector<uint8_t> &p_array);
	Error load_jpg_from_buffer(const Vector<uint8_t> &p_array);
	Error load_webp_from_buffer(const Vector<uint8_t> &p_array);
	Error load_tga_from_buffer(const Vector<uint8_t> &p_array);
	Error load_bmp_from_buffer(const Vector<uint8_t> &p_array);
	Error load_ktx_from_buffer(const Vector<uint8_t> &p_array);
	Error load_dds_from_buffer(const Vector<uint8_t> &p_array);

	Error load_svg_from_buffer(const Vector<uint8_t> &p_array, float scale = 1.0);
	Error load_svg_from_string(const String &p_svg_str, float scale = 1.0);

	void convert_rg_to_ra_rgba8();
	void convert_ra_rgba8_to_rg();
	void convert_rgba8_to_bgra8();

	UsedChannels detect_used_channels(CompressSource p_source = COMPRESS_SOURCE_GENERIC) const;
	void optimize_channels();

	Color get_pixelv(const Point2i &p_point) const;
	Color get_pixel(int p_x, int p_y) const;
	void set_pixelv(const Point2i &p_point, const Color &p_color);
	void set_pixel(int p_x, int p_y, const Color &p_color);

	const uint8_t *ptr() const;
	uint8_t *ptrw();
	int64_t get_data_size() const;

	void adjust_bcs(float p_brightness, float p_contrast, float p_saturation);

	void set_as_black();

	void copy_internals_from(const Ref<Image> &p_image);

	Dictionary compute_image_metrics(const Ref<Image> p_compared_image, bool p_luma_metric = true);
};

VARIANT_ENUM_CAST(Image::Format)
VARIANT_ENUM_CAST(Image::Interpolation)
VARIANT_ENUM_CAST(Image::CompressMode)
VARIANT_ENUM_CAST(Image::CompressSource)
VARIANT_ENUM_CAST(Image::UsedChannels)
VARIANT_ENUM_CAST(Image::AlphaMode)
VARIANT_ENUM_CAST(Image::RoughnessChannel)
VARIANT_ENUM_CAST(Image::ASTCFormat)