Method update

3rdparty/bgfx/src/renderer_gl.cpp:5984–6102

	}

	void TextureGL::update(uint8_t _side, uint8_t _mip, const Rect& _rect, uint16_t _z, uint16_t _depth, uint16_t _pitch, const Memory* _mem)
	{
		const uint32_t bpp = bimg::getBitsPerPixel(bimg::TextureFormat::Enum(m_textureFormat) );
		const uint32_t rectpitch = _rect.m_width*bpp/8;
		uint32_t srcpitch  = UINT16_MAX == _pitch ? rectpitch : _pitch;

		GL_CHECK(glBindTexture(m_target, m_id) );
		GL_CHECK(glPixelStorei(GL_UNPACK_ALIGNMENT, 1) );

		GLenum target = isCubeMap()
			? GL_TEXTURE_CUBE_MAP_POSITIVE_X
			: m_target
			;

		const bool swizzle = true
			&& TextureFormat::BGRA8 == m_requestedFormat
			&& !s_textureFormat[m_requestedFormat].m_supported
			&& !s_renderGL->m_textureSwizzleSupport
			;
		const bool unpackRowLength = !!BGFX_CONFIG_RENDERER_OPENGL || s_extension[Extension::EXT_unpack_subimage].m_supported;
		const bool compressed      = bimg::isCompressed(bimg::TextureFormat::Enum(m_requestedFormat) );
		const bool convert         = false
			|| (compressed && m_textureFormat != m_requestedFormat)
			|| swizzle
			;

		Rect rect;
		rect.setIntersect(_rect
			, {
				0, 0,
				uint16_t(bx::max(1u, m_width  >> _mip) ),
				uint16_t(bx::max(1u, m_height >> _mip) ),
			});

		uint32_t width  = rect.m_width;
		uint32_t height = rect.m_height;

		uint8_t* temp = NULL;
		if (convert
		||  !unpackRowLength)
		{
			temp = (uint8_t*)bx::alloc(g_allocator, rectpitch*height);
		}
		else if (unpackRowLength)
		{
			GL_CHECK(glPixelStorei(GL_UNPACK_ROW_LENGTH, srcpitch*8/bpp) );
		}

		if (compressed
		&& !convert)
		{
			const uint8_t* data = _mem->data;

			if (!unpackRowLength)
			{
				bimg::imageCopy(temp, width, height, 1, bpp, srcpitch, data);
				data = temp;
			}