android_webview/public/browser/draw_gl.h

   1 // Copyright 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef ANDROID_WEBVIEW_PUBLIC_BROWSER_DRAW_GL_H_
   6 #define ANDROID_WEBVIEW_PUBLIC_BROWSER_DRAW_GL_H_
   7
   8 #ifdef __cplusplus
   9 extern "C" {
  10 #endif
  11
  12
  13 // 1 is L/L MR1
  14 //
  15 // 2 starts at M, and added an imperfect workaround for complex clipping by
  16 // elevating the WebView into an FBO layer. If any transform, clip, or outline
  17 // clip occurs that would either likely use the stencil buffer for clipping, or
  18 // require shader based clipping in HWUI, the WebView is drawn into an FBO (if
  19 // it fits).
  20 // This is a temporary workaround for a lack of WebView support for stencil/
  21 // shader based round rect clipping, and should be removed when webview is
  22 // capable of supporting these clips internally when drawing.
  23 static const int kAwDrawGLInfoVersion = 2;
  24
  25 // Holds the information required to trigger an OpenGL drawing operation.
  26 struct AwDrawGLInfo {
  27   int version;  // The AwDrawGLInfo this struct was built with.
  28
  29   // Input: tells the draw function what action to perform.
  30   enum Mode {
  31     kModeDraw = 0,
  32     kModeProcess,
  33     kModeProcessNoContext,
  34     kModeSync,
  35   } mode;
  36
  37   // Input: current clip rect in surface coordinates. Reflects the current state
  38   // of the OpenGL scissor rect. Both the OpenGL scissor rect and viewport are
  39   // set by the caller of the draw function and updated during View animations.
  40   int clip_left;
  41   int clip_top;
  42   int clip_right;
  43   int clip_bottom;
  44
  45   // Input: current width/height of destination surface.
  46   int width;
  47   int height;
  48
  49   // Input: is the View rendered into an independent layer.
  50   // If false, the surface is likely to hold to the full screen contents, with
  51   // the scissor box set by the caller to the actual View location and size.
  52   // Also the transformation matrix will contain at least a translation to the
  53   // position of the View to render, plus any other transformations required as
  54   // part of any ongoing View animation. View translucency (alpha) is ignored,
  55   // although the framework will set is_layer to true for non-opaque cases.
  56   // Can be requested via the View.setLayerType(View.LAYER_TYPE_NONE, ...)
  57   // Android API method.
  58   //
  59   // If true, the surface is dedicated to the View and should have its size.
  60   // The viewport and scissor box are set by the caller to the whole surface.
  61   // Animation transformations are handled by the caller and not reflected in
  62   // the provided transformation matrix. Translucency works normally.
  63   // Can be requested via the View.setLayerType(View.LAYER_TYPE_HARDWARE, ...)
  64   // Android API method.
  65   bool is_layer;
  66
  67   // Input: current transformation matrix in surface pixels.
  68   // Uses the column-based OpenGL matrix format.
  69   float transform[16];
  70 };
  71
  72 // Function to invoke a direct GL draw into the client's pre-configured
  73 // GL context. Obtained via AwContents.getDrawGLFunction() (static).
  74 // |view_context| is an opaque identifier that was returned by the corresponding
  75 // call to AwContents.getAwDrawGLViewContext().
  76 // |draw_info| carries the in and out parameters for this draw.
  77 // |spare| ignored; pass NULL.
  78 typedef void (AwDrawGLFunction)(long view_context,
  79                                 AwDrawGLInfo* draw_info,
  80                                 void* spare);
  81 enum AwMapMode {
  82   MAP_READ_ONLY,
  83   MAP_WRITE_ONLY,
  84   MAP_READ_WRITE,
  85 };
  86
  87 // Called to create a GraphicBuffer
  88 typedef long AwCreateGraphicBufferFunction(int w, int h);
  89 // Called to release a GraphicBuffer
  90 typedef void AwReleaseGraphicBufferFunction(long buffer_id);
  91 // Called to map a GraphicBuffer in |mode|.
  92 typedef int AwMapFunction(long buffer_id, AwMapMode mode, void** vaddr);
  93 // Called to unmap a GraphicBuffer
  94 typedef int AwUnmapFunction(long buffer_id);
  95 // Called to get a native buffer pointer
  96 typedef void* AwGetNativeBufferFunction(long buffer_id);
  97 // Called to get the stride of the buffer
  98 typedef unsigned int AwGetStrideFunction(long buffer_id);
  99
 100 static const int kAwDrawGLFunctionTableVersion = 1;
 101
 102 // Set of functions used in rendering in hardware mode
 103 struct AwDrawGLFunctionTable {
 104   int version;
 105   AwCreateGraphicBufferFunction* create_graphic_buffer;
 106   AwReleaseGraphicBufferFunction* release_graphic_buffer;
 107   AwMapFunction* map;
 108   AwUnmapFunction* unmap;
 109   AwGetNativeBufferFunction* get_native_buffer;
 110   AwGetStrideFunction* get_stride;
 111 };
 112
 113 #ifdef __cplusplus
 114 }  // extern "C"
 115 #endif
 116
 117 #endif  // ANDROID_WEBVIEW_PUBLIC_BROWSER_DRAW_GL_H_