dom/canvas/WebGLVertexAttribData.cpp
author Sylvestre Ledru <sledru@mozilla.com>
Thu, 17 Aug 2017 11:13:01 +0200
changeset 648192 c236dfe7dc98c387219d7cb45d0693560db708fd
parent 454938 aa8818f7704553cadb3e3285913dd73c36d8c61f
child 489671 05d9746016f47666c00390aacc9f9d62c8ffffb4
permissions -rw-r--r--
indent all (with js specific coding style) MozReview-Commit-ID: LU1md2wyB8

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "WebGLVertexAttribData.h"

#include "GLContext.h"
#include "WebGLBuffer.h"

namespace mozilla {

static uint8_t
CalcBytesPerVertex(GLenum type, uint8_t size)
{
  uint8_t bytesPerType;
  switch (type) {
    case LOCAL_GL_INT_2_10_10_10_REV:
    case LOCAL_GL_UNSIGNED_INT_2_10_10_10_REV:
      return 4;

    case LOCAL_GL_BYTE:
    case LOCAL_GL_UNSIGNED_BYTE:
      bytesPerType = 1;
      break;

    case LOCAL_GL_HALF_FLOAT:
    case LOCAL_GL_SHORT:
    case LOCAL_GL_UNSIGNED_SHORT:
      bytesPerType = 2;
      break;

    case LOCAL_GL_FIXED: // GLES 3.0.4 p9: 32-bit signed, with 16 fractional bits.
    case LOCAL_GL_FLOAT:
    case LOCAL_GL_INT:
    case LOCAL_GL_UNSIGNED_INT:
      bytesPerType = 4;
      break;

    default:
      MOZ_CRASH("Bad `type`.");
  }

  return bytesPerType * size;
}

static GLenum
AttribPointerBaseType(bool integerFunc, GLenum type)
{
  if (!integerFunc)
    return LOCAL_GL_FLOAT;

  switch (type) {
    case LOCAL_GL_BYTE:
    case LOCAL_GL_SHORT:
    case LOCAL_GL_INT:
      return LOCAL_GL_INT;

    case LOCAL_GL_UNSIGNED_BYTE:
    case LOCAL_GL_UNSIGNED_SHORT:
    case LOCAL_GL_UNSIGNED_INT:
      return LOCAL_GL_UNSIGNED_INT;

    default:
      MOZ_CRASH();
  }
}

void
WebGLVertexAttribData::VertexAttribPointer(bool integerFunc,
                                           WebGLBuffer* buf,
                                           uint8_t size,
                                           GLenum type,
                                           bool normalized,
                                           uint32_t stride,
                                           uint64_t byteOffset)
{
  mIntegerFunc = integerFunc;
  WebGLBuffer::SetSlot(0, buf, &mBuf);
  mType = type;
  mBaseType = AttribPointerBaseType(integerFunc, type);
  mSize = size;
  mBytesPerVertex = CalcBytesPerVertex(mType, mSize);
  mNormalized = normalized;
  mStride = stride;
  mExplicitStride = (mStride ? mStride : mBytesPerVertex);
  mByteOffset = byteOffset;
}

void
WebGLVertexAttribData::DoVertexAttribPointer(gl::GLContext* gl,
                                             GLuint index) const
{
  if (mIntegerFunc) {
    gl->fVertexAttribIPointer(
      index, mSize, mType, mStride, (const void*)mByteOffset);
  } else {
    gl->fVertexAttribPointer(
      index, mSize, mType, mNormalized, mStride, (const void*)mByteOffset);
  }
}

} // namespace mozilla