| // 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. |
| |
| #ifndef REMOTING_CLIENT_OPENGL_GL_CANVAS_H_ |
| #define REMOTING_CLIENT_OPENGL_GL_CANVAS_H_ |
| |
| #include <array> |
| |
| #include "base/macros.h" |
| #include "base/threading/thread_checker.h" |
| #include "remoting/client/sys_opengl.h" |
| |
| namespace remoting { |
| |
| // This class holds zoom and pan configurations of the canvas and is used to |
| // draw textures on the canvas. |
| // Must be constructed after the OpenGL surface is created and destroyed before |
| // the surface is destroyed. |
| // |
| // Coordinates to be used for GlCanvas should be normalized texture coordinates. |
| // In the view of a point on the canvas, the canvas has width 1 and height 1, |
| // with the origin at the upper-left corner of the canvas. |
| class GlCanvas { |
| public: |
| // gl_version: version number of the OpenGL ES context. Either 2 or 3. |
| GlCanvas(int gl_version); |
| |
| ~GlCanvas(); |
| |
| // Sets the normalized transformation matrix. This matrix defines how the |
| // canvas should be shown on the view. |
| // 3 by 3 transformation matrix, [ m0, m1, m2, m3, m4, m5, m6, m7, m8 ]. |
| // The matrix will be multiplied with the positions (with projective space, |
| // (x, y, 1)) to draw the textures with the right zoom and pan configuration. |
| // |
| // | m0, m1, m2, | | x | |
| // | m3, m4, m5, | * | y | |
| // | m6, m7, m8 | | 1 | |
| // |
| // For a typical transformation matrix such that m1=m3=m6=m7=0 and m8=1, m0 |
| // and m4 defines the ratio of canvas width or height over view width or |
| // height. m2 and m5 defines the offset of the upper-left corner in percentage |
| // of the view's width or height. An identity matrix will stretch the canvas |
| // to fit the whole view. |
| void SetNormalizedTransformation(const std::array<float, 9>& matrix); |
| |
| // Draws the texture on the canvas. Nothing will happen if |
| // SetNormalizedTransformation() has not been called. |
| // vertex_buffer: reference to the 2x4x2 float vertex buffer. |
| // [ four (x, y) normalized vertex positions on the canvas, |
| // four (x, y) vertex positions to define the visible area ] |
| void DrawTexture(int texture_id, GLuint texture_handle, GLuint vertex_buffer); |
| |
| // Returns the version number of current OpenGL ES context. Either 2 or 3. |
| int GetGlVersion() const; |
| |
| private: |
| int gl_version_; |
| |
| // True IFF the transformation has been set. |
| bool transformation_set_ = false; |
| |
| // Handles. |
| GLuint vertex_shader_; |
| GLuint fragment_shader_; |
| GLuint program_; |
| |
| // Locations of the corresponding shader attributes. |
| GLuint transform_location_; |
| GLuint texture_location_; |
| GLuint position_location_; |
| GLuint tex_cord_location_; |
| |
| base::ThreadChecker thread_checker_; |
| |
| DISALLOW_COPY_AND_ASSIGN(GlCanvas); |
| }; |
| |
| } // namespace remoting |
| |
| #endif // REMOTING_CLIENT_OPENGL_GL_CANVAS_H_ |