/* -*- 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 "WebGL2Context.h"

#include "GLContext.h"
#include "WebGLFramebuffer.h"

namespace mozilla {

bool WebGL2Context::ValidateClearBuffer(const char* funcName, GLenum buffer,
                                        GLint drawBuffer, size_t availElemCount,
                                        GLuint elemOffset, GLenum funcType) {
  if (elemOffset > availElemCount) {
    ErrorInvalidValue("%s: Offset too big for list.", funcName);
    return false;
  }
  availElemCount -= elemOffset;

  ////

  size_t requiredElements;
  GLint maxDrawBuffer;
  switch (buffer) {
    case LOCAL_GL_COLOR:
      requiredElements = 4;
      maxDrawBuffer = mGLMaxDrawBuffers - 1;
      break;

    case LOCAL_GL_DEPTH:
    case LOCAL_GL_STENCIL:
      requiredElements = 1;
      maxDrawBuffer = 0;
      break;

    case LOCAL_GL_DEPTH_STENCIL:
      requiredElements = 2;
      maxDrawBuffer = 0;
      break;

    default:
      ErrorInvalidEnumInfo(funcName, buffer);
      return false;
  }

  if (drawBuffer < 0 || drawBuffer > maxDrawBuffer) {
    ErrorInvalidValue(
        "%s: Invalid drawbuffer %d. This buffer only supports"
        " `drawbuffer` values between 0 and %u.",
        funcName, drawBuffer, maxDrawBuffer);
    return false;
  }

  if (availElemCount < requiredElements) {
    ErrorInvalidValue("%s: Not enough elements. Require %zu. Given %zu.",
                      funcName, requiredElements, availElemCount);
    return false;
  }

  ////

  if (!BindCurFBForDraw(funcName)) return false;

  const auto& fb = mBoundDrawFramebuffer;
  if (fb) {
    if (!fb->ValidateClearBufferType(funcName, buffer, drawBuffer, funcType))
      return false;
  } else if (buffer == LOCAL_GL_COLOR) {
    if (drawBuffer != 0) return true;

    if (mDefaultFB_DrawBuffer0 == LOCAL_GL_NONE) return true;

    if (funcType != LOCAL_GL_FLOAT) {
      ErrorInvalidOperation(
          "%s: For default framebuffer, COLOR is always of type"
          " FLOAT.",
          funcName);
      return false;
    }
  }

  return true;
}

////

void WebGL2Context::ClearBufferfv(GLenum buffer, GLint drawBuffer,
                                  const Float32Arr& src, GLuint srcElemOffset) {
  const char funcName[] = "clearBufferfv";
  if (IsContextLost()) return;

  if (buffer != LOCAL_GL_COLOR && buffer != LOCAL_GL_DEPTH) {
    ErrorInvalidEnum("%s: buffer must be COLOR or DEPTH.", funcName);
    return;
  }

  if (!ValidateClearBuffer(funcName, buffer, drawBuffer, src.elemCount,
                           srcElemOffset, LOCAL_GL_FLOAT)) {
    return;
  }

  if (!mBoundDrawFramebuffer && buffer == LOCAL_GL_DEPTH && mNeedsFakeNoDepth) {
    return;
  }

  ScopedDrawCallWrapper wrapper(*this);
  const auto ptr = src.elemBytes + srcElemOffset;
  gl->fClearBufferfv(buffer, drawBuffer, ptr);
}

void WebGL2Context::ClearBufferiv(GLenum buffer, GLint drawBuffer,
                                  const Int32Arr& src, GLuint srcElemOffset) {
  const char funcName[] = "clearBufferiv";
  if (IsContextLost()) return;

  if (buffer != LOCAL_GL_COLOR && buffer != LOCAL_GL_STENCIL) {
    ErrorInvalidEnum("%s: buffer must be COLOR or STENCIL.", funcName);
    return;
  }

  if (!ValidateClearBuffer(funcName, buffer, drawBuffer, src.elemCount,
                           srcElemOffset, LOCAL_GL_INT)) {
    return;
  }

  if (!mBoundDrawFramebuffer && buffer == LOCAL_GL_STENCIL &&
      mNeedsFakeNoStencil) {
    return;
  }

  ScopedDrawCallWrapper wrapper(*this);
  const auto ptr = src.elemBytes + srcElemOffset;
  gl->fClearBufferiv(buffer, drawBuffer, ptr);
}

void WebGL2Context::ClearBufferuiv(GLenum buffer, GLint drawBuffer,
                                   const Uint32Arr& src, GLuint srcElemOffset) {
  const char funcName[] = "clearBufferuiv";
  if (IsContextLost()) return;

  if (buffer != LOCAL_GL_COLOR)
    return ErrorInvalidEnum("%s: buffer must be COLOR.", funcName);

  if (!ValidateClearBuffer(funcName, buffer, drawBuffer, src.elemCount,
                           srcElemOffset, LOCAL_GL_UNSIGNED_INT)) {
    return;
  }

  ScopedDrawCallWrapper wrapper(*this);
  const auto ptr = src.elemBytes + srcElemOffset;
  gl->fClearBufferuiv(buffer, drawBuffer, ptr);
}

////

void WebGL2Context::ClearBufferfi(GLenum buffer, GLint drawBuffer,
                                  GLfloat depth, GLint stencil) {
  const char funcName[] = "clearBufferfi";
  if (IsContextLost()) return;

  if (buffer != LOCAL_GL_DEPTH_STENCIL)
    return ErrorInvalidEnum("%s: buffer must be DEPTH_STENCIL.", funcName);

  if (!ValidateClearBuffer(funcName, buffer, drawBuffer, 2, 0, 0)) return;

  auto driverDepth = depth;
  auto driverStencil = stencil;
  if (!mBoundDrawFramebuffer) {
    if (mNeedsFakeNoDepth) {
      driverDepth = 1.0f;
    } else if (mNeedsFakeNoStencil) {
      driverStencil = 0;
    }
  }

  ScopedDrawCallWrapper wrapper(*this);
  gl->fClearBufferfi(buffer, drawBuffer, driverDepth, driverStencil);
}

}  // namespace mozilla