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// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <array>
#include <memory>
#include "base/macros.h"
#include "base/memory/weak_ptr.h"
#include "base/threading/thread_checker.h"
#include "remoting/client/display/sys_opengl.h"
namespace remoting {
class Canvas;
// This class is for drawing a texture on the canvas. Must be deleted before the
// canvas is deleted.
class GlRenderLayer {
static const int kBytesPerPixel = 4;
// texture_id: An integer in range [0, GL_MAX_TEXTURE_IMAGE_UNITS], defining
// which slot to store the texture.
GlRenderLayer(int texture_id, base::WeakPtr<Canvas> canvas);
// Sets the texture (RGBA 8888) to be drawn. Please use UpdateTexture() if the
// texture size isn't changed.
// stride: byte distance between two rows in |subtexture|.
// If |stride| is 0 or |stride| == |width|*kBytesPerPixel, |subtexture| will
// be treated as tightly packed.
void SetTexture(const uint8_t* texture, int width, int height, int stride);
// Updates a subregion (RGBA 8888) of the texture. Can only be called after
// SetTexture() has been called.
// stride: See SetTexture().
void UpdateTexture(const uint8_t* subtexture,
int offset_x,
int offset_y,
int width,
int height,
int stride);
// Sets the positions of four vertices of the texture in pixel with respect to
// the canvas.
// positions: [ x_upperleft, y_upperleft, x_lowerleft, y_lowerleft,
// x_upperright, y_upperright, x_lowerright, y_lowerright ]
void SetVertexPositions(const std::array<float, 8>& positions);
// Sets the visible area of the texture in percentage of the width and height
// of the texture. The default values are (0, 0), (0, 1), (1, 0), (1, 1),
// i.e. showing the whole texture.
// positions: [ x_upperleft, y_upperleft, x_lowerleft, y_lowerleft,
// x_upperright, y_upperright, x_lowerright, y_lowerright ]
void SetTextureVisibleArea(const std::array<float, 8>& positions);
// Draws the texture on the canvas. Texture must be set before calling Draw().
void Draw(float alpha_multiplier);
// true if the texture is already set by calling SetTexture().
bool is_texture_set() { return texture_set_; }
// Returns pointer to the texture buffer that can be used by glTexImage2d or
// glTexSubImage2d. The returned value will be |data| if the texture can be
// used without manual packing, otherwise the data will be manually packed and
// the pointer to |update_buffer_| will be returned.
// should_reset_row_length: Pointer to a bool that will be set by the
// function. If this is true, the user need to call
// glPixelStorei(GL_UNPACK_ROW_LENGTH, 0) after
// updating the texture to reset the stride.
const uint8_t* PrepareTextureBuffer(const uint8_t* data,
int width,
int height,
int stride,
bool* should_reset_row_length);
int texture_id_;
base::WeakPtr<Canvas> canvas_;
GLuint texture_handle_;
GLuint buffer_handle_;
bool texture_set_ = false;
bool vertex_position_set_ = false;
// Used in OpenGL ES 2 context which doesn't support GL_UNPACK_ROW_LENGTH to
// tightly pack dirty regions before sending them to GPU.
std::unique_ptr<uint8_t[]> update_buffer_;
int update_buffer_size_ = 0;
base::ThreadChecker thread_checker_;
} // namespace remoting