axmol/core/renderer/backend/opengl/TextureGL.h

/****************************************************************************
 Copyright (c) 2018-2019 Xiamen Yaji Software Co., Ltd.

 https://axmolengine.github.io/

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#pragma once

#include <array>
#include "../Texture.h"
#include "platform/GL.h"
#include "base/EventListenerCustom.h"

NS_AX_BACKEND_BEGIN

/**
 * Store texture information.
 */
struct TextureInfoGL
{
    void applySampler(const SamplerDescriptor& desc, bool isPow2, bool hasMipmaps, GLenum target);
    void setCurrentTexParameters(GLenum target);

    TextureInfoGL() { textures.fill(0); }
    ~TextureInfoGL() { destroy(); }

    template <typename _Fty>
    void foreachTextures(const _Fty& cb) const
    {
        GLuint texID;
        int idx = 0;
        while ((texID = textures[idx]))
            cb(texID, idx++);
    }

    GLuint ensure(int index, GLenum target);
    void recreateAll(GLenum target);

    void destroy()
    {
        foreachTextures([=](GLuint texID, int) { glDeleteTextures(1, &texID); });
        textures.fill(0);
    }

    /// <summary>
    /// Apply shader texture
    /// </summary>
    /// <param name="slot">the slot in shader</param>
    /// <param name="index">the index in meta textrues</param>
    /// <param name="target">the target GL_TEXTURE_2D,GL_TEXTURE_CUBE_MAP</param>
    void apply(int slot, int index, GLenum target) const;
    GLuint getName(int index) const { return textures[0]; }

    GLint magFilterGL    = GL_LINEAR;
    GLint minFilterGL    = GL_LINEAR;
    GLint sAddressModeGL = GL_REPEAT;
    GLint tAddressModeGL = GL_REPEAT;

    // Used in glTexImage2D().
    GLint internalFormat = GL_RGBA;
    GLenum format        = GL_RGBA;
    GLenum type          = GL_UNSIGNED_BYTE;

    std::array<GLuint, AX_META_TEXTURES + 1> textures;
    int maxIdx = 0;
};

/**
 * @addtogroup _opengl
 * @{
 */

/**
 * A 2D texture
 */
class Texture2DGL : public backend::Texture2DBackend
{
public:
    /**
     * @param descirptor Specifies the texture description.
     */
    Texture2DGL(const TextureDescriptor& descriptor);
    ~Texture2DGL();

    /**
     * Update a two-dimensional texture image
     * @param data Specifies a pointer to the image data in memory.
     * @param width Specifies the width of the texture image.
     * @param height Specifies the height of the texture image.
     * @param level Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap
     * reduction image.
     */
    virtual void updateData(uint8_t* data,
                            std::size_t width,
                            std::size_t height,
                            std::size_t level,
                            int index = 0) override;

    /**
     * Update a two-dimensional texture image in a compressed format
     * @param data Specifies a pointer to the compressed image data in memory.
     * @param width Specifies the width of the texture image.
     * @param height Specifies the height of the texture image.
     * @param dataLen Specifies the totoal size of compressed image in bytes.
     * @param level Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap
     * reduction image.
     */
    virtual void updateCompressedData(uint8_t* data,
                                      std::size_t width,
                                      std::size_t height,
                                      std::size_t dataLen,
                                      std::size_t level,
                                      int index = 0) override;

    /**
     * Update a two-dimensional texture subimage
     * @param xoffset Specifies a texel offset in the x direction within the texture array.
     * @param yoffset Specifies a texel offset in the y direction within the texture array.
     * @param width Specifies the width of the texture subimage.
     * @param height Specifies the height of the texture subimage.
     * @param level Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap
     * reduction image.
     * @param data Specifies a pointer to the image data in memory.
     */
    virtual void updateSubData(std::size_t xoffset,
                               std::size_t yoffset,
                               std::size_t width,
                               std::size_t height,
                               std::size_t level,
                               uint8_t* data,
                               int index = 0) override;

    /**
     * Update a two-dimensional texture subimage in a compressed format
     * @param xoffset Specifies a texel offset in the x direction within the texture array.
     * @param yoffset Specifies a texel offset in the y direction within the texture array.
     * @param width Specifies the width of the texture subimage.
     * @param height Specifies the height of the texture subimage.
     * @param dataLen Specifies the totoal size of compressed subimage in bytes.
     * @param level Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap
     * reduction image.
     * @param data Specifies a pointer to the compressed image data in memory.
     */
    virtual void updateCompressedSubData(std::size_t xoffset,
                                         std::size_t yoffset,
                                         std::size_t width,
                                         std::size_t height,
                                         std::size_t dataLen,
                                         std::size_t level,
                                         uint8_t* data,
                                         int index = 0) override;

    /**
     * Update sampler
     * @param sampler Specifies the sampler descriptor.
     */
    virtual void updateSamplerDescriptor(const SamplerDescriptor& sampler) override;

    /**
     * Generate mipmaps.
     */
    virtual void generateMipmaps() override;

    /**
     * Update texture description.
     * @param descriptor Specifies texture and sampler descriptor.
     */
    virtual void updateTextureDescriptor(const TextureDescriptor& descriptor, int index = 0) override;

    /**
     * Get texture object.
     * @return Texture object.
     */
    uintptr_t getHandler(int index = 0) const override { return _textureInfo.textures[index]; }

    /**
     * Set texture to pipeline
     * @param index Specifies the texture image unit selector.
     */
    void apply(int slot, int index) const { _textureInfo.apply(slot, index, GL_TEXTURE_2D); }

    int getCount() const override { return _textureInfo.maxIdx + 1; }

private:
    void initWithZeros();

    TextureInfoGL _textureInfo;
    EventListener* _backToForegroundListener = nullptr;
};

/**
 * Texture cube.
 */
class TextureCubeGL : public backend::TextureCubemapBackend
{
public:
    /**
     * @param descirptor Specifies the texture description.
     */
    TextureCubeGL(const TextureDescriptor& descriptor);
    ~TextureCubeGL();

    /**
     * Update sampler
     * @param sampler Specifies the sampler descriptor.
     */
    virtual void updateSamplerDescriptor(const SamplerDescriptor& sampler) override;

    /**
     * Update texutre cube data in give slice side.
     * @param side Specifies which slice texture of cube to be update.
     * @param data Specifies a pointer to the image data in memory.
     */
    virtual void updateFaceData(TextureCubeFace side, void* data, int index = 0) override;

    /// Generate mipmaps.
    virtual void generateMipmaps() override;

    /**
     * Update texture description.
     * @param descriptor Specifies texture and sampler descriptor.
     */
    virtual void updateTextureDescriptor(const TextureDescriptor& descriptor, int index = 0) override;

    /**
     * Get texture object.
     * @return Texture object.
     */
    uintptr_t getHandler(int index = 0) const override { return _textureInfo.textures[index]; }

    /**
     * Set texture to pipeline
     * @param index Specifies the texture image unit selector.
     */
    void apply(int slot, int index) const { _textureInfo.apply(slot, index, GL_TEXTURE_CUBE_MAP); }

    int getCount() const override { return _textureInfo.maxIdx + 1; }

private:
    TextureInfoGL _textureInfo;
    EventListener* _backToForegroundListener = nullptr;
};

// end of _opengl group
/// @}
NS_AX_BACKEND_END