Method InitFromRGBA

engine/PoseidonGL33/TextureGL33_Init.cpp:513–583

}

bool TextureGL33::InitFromRGBA(int w, int h, const void* rgba, uint32_t size, bool mipmap)
{
    if (!rgba)
        return false;

    _initialized = true;
    _dynamicMipmapped = mipmap;

    int maxLevel = 0;
    if (mipmap)
    {
        int dim = w > h ? w : h;
        while (dim > 1)
        {
            dim >>= 1;
            maxLevel++;
        }
    }
    _nMipmaps = maxLevel + 1;
    _mipmaps[0]._w = static_cast<short>(w);
    _mipmaps[0]._h = static_cast<short>(h);
    _mipmaps[0]._pitch = static_cast<short>(w * 4);
    _maxSize = w > h ? w : h;

    unsigned int tex = 0;
    glGenTextures(1, &tex);
    if (!tex)
        return false;

    _surface.SetTexture(tex);
    GL33Bind::Tex2D(EngineGL33::kUploadUnit - GL_TEXTURE0, tex);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, rgba);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, 0);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, maxLevel);
    if (mipmap)
    {
        glGenerateMipmap(GL_TEXTURE_2D);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
        // Anisotropic filter keeps tilted-surface sampling crisp — isotropic LOD
        // over-blurs because the per-fragment UV footprint is elongated.
        float maxAniso = 1.0f;
        glGetFloatv(GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, &maxAniso);
        if (maxAniso > 1.0f)
        {
            float aniso = maxAniso < 8.0f ? maxAniso : 8.0f;
            glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, aniso);
        }
    }
    else
    {
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    }
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    GL33Bind::ActiveUnit(0);