our_dick/include/graphics/texture.hpp

/**
	This file is a part of our_dick
	Copyright (C) 2020-2022 rexy712

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU Affero General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU Affero General Public License for more details.

	You should have received a copy of the GNU Affero General Public License
	along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef OUR_DICK_GRAPHICS_TEXTURE_HPP
#define OUR_DICK_GRAPHICS_TEXTURE_HPP

#include "engine/image.hpp"
#include "gl_include.hpp"
#include "math/vec.hpp"

namespace gfx{

	class texture;

	class weak_texture_handle
	{
	private:
		const texture* m_texture;

	public:
		weak_texture_handle(const texture& tex);
		weak_texture_handle(const weak_texture_handle&) = default;
		weak_texture_handle(weak_texture_handle&&) = default;
		~weak_texture_handle(void) = default;

		weak_texture_handle& operator=(const weak_texture_handle&) = default;
		weak_texture_handle& operator=(weak_texture_handle&&) = default;

		GLuint raw(void)const;
		GLsizei get_width(void)const;
		GLsizei get_height(void)const;

		void bind(void)const;
		void bind_unit(GLuint tunit)const;
	};

	//class representing an opengl 2D texture
	class texture
	{
	public:
		//all available wrapping styles as a strongly typed enum
		enum class wrap : GLint{
			CLAMP_EDGE = GL_CLAMP_TO_EDGE,
			CLAMP_BORDER = GL_CLAMP_TO_BORDER,
			MIRROR_REPEAT = GL_MIRRORED_REPEAT,
			REPEAT = GL_REPEAT,
			MIRROR_CLAMP_EDGE = GL_MIRROR_CLAMP_TO_EDGE,
		};
		//all available minfilter styles as a strongly typed enum
		enum class minfilter : GLint{
			NEAREST = GL_NEAREST,
			LINEAR = GL_LINEAR,
			NMIPMAP_NEAREST = GL_NEAREST_MIPMAP_NEAREST,
			LMIPMAP_NEAREST = GL_LINEAR_MIPMAP_NEAREST,
			NMIPMAP_LINEAR = GL_NEAREST_MIPMAP_LINEAR,
			LMIPMAP_LINEAR = GL_LINEAR_MIPMAP_LINEAR,
		};
		//all available magfilter styles as a strongly typed enum
		enum class magfilter : GLint{
			NEAREST = GL_NEAREST,
			LINEAR = GL_LINEAR,
		};
	private:
		GLuint m_tex_id = 0; //handle to texture object
		GLsizei m_width = 0;
		GLsizei m_height = 0;
		GLenum m_format = 0;
		GLenum m_type = GL_UNSIGNED_BYTE;
		bool m_mipmapped = true;

	public:
		//create the texture with no image data
		texture(void);
		texture(const unsigned char* data, GLenum format, GLsizei w, GLsizei h, GLenum type, bool mipmap = true);
		texture(GLenum format, GLsizei w, GLsizei h, GLenum type, bool mipmap = true);
		//create the texture with image data from 'i'
		texture(const egn::image& i, bool mipmap = true);
		texture(const egn::deferred_image& i, bool mipmap = true);
		texture(const texture&);
		texture(texture&&);
		~texture(void);

		texture& operator=(const texture&);
		texture& operator=(texture&&);

		GLuint raw(void)const;

		//overwrite the current image data with 'i'
		bool set_image(const unsigned char* data, GLenum format, GLsizei w, GLsizei h, GLenum type);
		bool set_image(const egn::image& i);
		bool set_image(const egn::deferred_image& i);

		bool set_subimage(const unsigned char* data, GLenum format, GLenum type,
		                  GLsizei xoffset, GLsizei yoffset, GLsizei w, GLsizei h);
		bool set_subimage(const egn::image& i, GLsizei xoffset, GLsizei yoffset);
		bool set_subimage(const egn::deferred_image& i, GLsizei xoffset, GLsizei yoffset);

		//change wrap mode for both x and y
		void set_wrap_mode(wrap w);
		void set_wrap_mode(wrap w, wrap h);
		//change wrap mode for one direction
		void set_wrap_x(wrap w);
		void set_wrap_y(wrap h);

		void set_border_color(GLfloat r, GLfloat g, GLfloat b, GLfloat a = 1.0f);
		void set_filter(minfilter min, magfilter mag);
		void set_mag_filter(magfilter m);
		void set_min_filter(minfilter m);

		magfilter get_mag_filter(void)const;
		minfilter get_min_filter(void)const;
		math::vec4<GLfloat> get_border_color(void)const;

		wrap get_wrap_x(void)const;
		wrap get_wrap_y(void)const;

		GLsizei get_width(void)const;
		GLsizei get_height(void)const;

		void enable_auto_mipmap(bool enable);
		void generate_mipmap(void);

		//release ownership of this texture object
		GLuint release(void);

		//bind to GL_TEXTURE_2D
		void bind(void)const;
		//bind to given texture unit and load into given program uniform location
		void bind_unit(GLuint tunit)const;

		weak_texture_handle create_handle(void)const;

	private:
		bool create_texture_storage_(void);
	};

}

#endif