dom/canvas/WebGLVertexArrayFake.cpp

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "WebGLVertexArrayFake.h"
   7
   8 #include "GLContext.h"
   9 #include "WebGLBuffer.h"
  10 #include "WebGLContext.h"
  11
  12 namespace mozilla {
  13
  14 static void BindBuffer(gl::GLContext* const gl, const GLenum target,
  15                        WebGLBuffer* const buffer) {
  16   gl->fBindBuffer(target, buffer ? buffer->mGLName : 0);
  17 }
  18
  19 WebGLVertexArrayFake::WebGLVertexArrayFake(WebGLContext* webgl)
  20     : WebGLVertexArray(webgl) {}
  21
  22 void WebGLVertexArray::DoVertexAttrib(const uint32_t index,
  23                                       const uint32_t vertOffset) const {
  24   const auto& gl = mContext->gl;
  25
  26   const bool useDivisor =
  27       mContext->IsWebGL2() ||
  28       mContext->IsExtensionEnabled(WebGLExtensionID::ANGLE_instanced_arrays);
  29
  30   const auto& binding = mBindings.at(index);
  31   const auto& desc = mDescs.at(index);
  32
  33   if (binding.layout.isArray) {
  34     gl->fEnableVertexAttribArray(index);
  35   } else {
  36     gl->fDisableVertexAttribArray(index);
  37   }
  38
  39   if (useDivisor) {
  40     gl->fVertexAttribDivisor(index, binding.layout.divisor);
  41   }
  42
  43   static_assert(IsBufferTargetLazilyBound(LOCAL_GL_ARRAY_BUFFER));
  44   BindBuffer(gl, LOCAL_GL_ARRAY_BUFFER, binding.buffer);
  45
  46   auto desc2 = desc;
  47   if (!binding.layout.divisor) {
  48     desc2.byteOffset += binding.layout.byteStride * vertOffset;
  49   }
  50   DoVertexAttribPointer(*gl, index, desc2);
  51
  52   BindBuffer(gl, LOCAL_GL_ARRAY_BUFFER, nullptr);
  53 }
  54
  55 void WebGLVertexArrayFake::BindVertexArray() {
  56   // Go through and re-bind all buffers and setup all
  57   // vertex attribute pointers
  58   const auto& gl = mContext->gl;
  59
  60   mContext->mBoundVertexArray = this;
  61
  62   static_assert(IsBufferTargetLazilyBound(LOCAL_GL_ARRAY_BUFFER));
  63   static_assert(!IsBufferTargetLazilyBound(LOCAL_GL_ELEMENT_ARRAY_BUFFER));
  64
  65   BindBuffer(gl, LOCAL_GL_ELEMENT_ARRAY_BUFFER, mElementArrayBuffer);
  66
  67   for (const auto i : IntegerRange(mContext->MaxVertexAttribs())) {
  68     DoVertexAttrib(i);
  69   }
  70 }
  71
  72 }  // namespace mozilla