/* -*- Mode: C++; tab-width: 20; 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 "WebGLUniformLocation.h"

#include "GLContext.h"
#include "mozilla/dom/ToJSValue.h"
#include "mozilla/dom/WebGLRenderingContextBinding.h"
#include "WebGLActiveInfo.h"
#include "WebGLContext.h"
#include "WebGLProgram.h"

namespace mozilla {

WebGLUniformLocation::WebGLUniformLocation(
    WebGLContext* webgl, const webgl::LinkedProgramInfo* linkInfo,
    webgl::UniformInfo* info, GLuint loc, size_t arrayIndex)
    : WebGLContextBoundObject(webgl),
      mLinkInfo(linkInfo),
      mInfo(info),
      mLoc(loc),
      mArrayIndex(arrayIndex) {}

WebGLUniformLocation::~WebGLUniformLocation() {}

bool WebGLUniformLocation::ValidateForProgram(const WebGLProgram* prog,
                                              const char* funcName) const {
  // Check the weak-pointer.
  if (!mLinkInfo) {
    mContext->ErrorInvalidOperation(
        "%s: This uniform location is obsolete because"
        " its program has been successfully relinked.",
        funcName);
    return false;
  }

  if (mLinkInfo->prog != prog) {
    mContext->ErrorInvalidOperation(
        "%s: This uniform location corresponds to a"
        " different program.",
        funcName);
    return false;
  }

  return true;
}

static bool IsUniformSetterTypeValid(GLenum setterType, GLenum uniformType) {
  // The order in this switch matches table 2.10 from OpenGL ES
  // 3.0.4 (Aug 27, 2014) es_spec_3.0.4.pdf
  switch (uniformType) {
    case LOCAL_GL_FLOAT:
    case LOCAL_GL_FLOAT_VEC2:
    case LOCAL_GL_FLOAT_VEC3:
    case LOCAL_GL_FLOAT_VEC4:
      return setterType == LOCAL_GL_FLOAT;

    case LOCAL_GL_INT:
    case LOCAL_GL_INT_VEC2:
    case LOCAL_GL_INT_VEC3:
    case LOCAL_GL_INT_VEC4:
      return setterType == LOCAL_GL_INT;

    case LOCAL_GL_UNSIGNED_INT:
    case LOCAL_GL_UNSIGNED_INT_VEC2:
    case LOCAL_GL_UNSIGNED_INT_VEC3:
    case LOCAL_GL_UNSIGNED_INT_VEC4:
      return setterType == LOCAL_GL_UNSIGNED_INT;

      /* bool can be set via any function: 0, 0.0f -> FALSE, _ -> TRUE */
    case LOCAL_GL_BOOL:
    case LOCAL_GL_BOOL_VEC2:
    case LOCAL_GL_BOOL_VEC3:
    case LOCAL_GL_BOOL_VEC4:
      return (setterType == LOCAL_GL_INT || setterType == LOCAL_GL_FLOAT ||
              setterType == LOCAL_GL_UNSIGNED_INT);

    case LOCAL_GL_FLOAT_MAT2:
    case LOCAL_GL_FLOAT_MAT3:
    case LOCAL_GL_FLOAT_MAT4:
    case LOCAL_GL_FLOAT_MAT2x3:
    case LOCAL_GL_FLOAT_MAT2x4:
    case LOCAL_GL_FLOAT_MAT3x2:
    case LOCAL_GL_FLOAT_MAT3x4:
    case LOCAL_GL_FLOAT_MAT4x2:
    case LOCAL_GL_FLOAT_MAT4x3:
      return setterType == LOCAL_GL_FLOAT;

      /* Samplers can only be set via Uniform1i */
    case LOCAL_GL_SAMPLER_2D:
    case LOCAL_GL_SAMPLER_3D:
    case LOCAL_GL_SAMPLER_CUBE:
    case LOCAL_GL_SAMPLER_2D_SHADOW:
    case LOCAL_GL_SAMPLER_2D_ARRAY:
    case LOCAL_GL_SAMPLER_2D_ARRAY_SHADOW:
    case LOCAL_GL_SAMPLER_CUBE_SHADOW:

    case LOCAL_GL_INT_SAMPLER_2D:
    case LOCAL_GL_INT_SAMPLER_3D:
    case LOCAL_GL_INT_SAMPLER_CUBE:
    case LOCAL_GL_INT_SAMPLER_2D_ARRAY:

    case LOCAL_GL_UNSIGNED_INT_SAMPLER_2D:
    case LOCAL_GL_UNSIGNED_INT_SAMPLER_3D:
    case LOCAL_GL_UNSIGNED_INT_SAMPLER_CUBE:
    case LOCAL_GL_UNSIGNED_INT_SAMPLER_2D_ARRAY:
      return setterType == LOCAL_GL_INT;

    default:
      MOZ_CRASH("GFX: Bad `uniformType`.");
  }
}

bool WebGLUniformLocation::ValidateSizeAndType(uint8_t setterElemSize,
                                               GLenum setterType,
                                               const char* funcName) const {
  MOZ_ASSERT(mLinkInfo);

  const auto& uniformElemSize = mInfo->mActiveInfo->mElemSize;
  if (setterElemSize != uniformElemSize) {
    mContext->ErrorInvalidOperation(
        "%s: Function used differs from uniform size: %i", funcName,
        uniformElemSize);
    return false;
  }

  const auto& uniformElemType = mInfo->mActiveInfo->mElemType;
  if (!IsUniformSetterTypeValid(setterType, uniformElemType)) {
    mContext->ErrorInvalidOperation(
        "%s: Function used is incompatible with uniform"
        " type: %i",
        funcName, uniformElemType);
    return false;
  }

  return true;
}

bool WebGLUniformLocation::ValidateArrayLength(uint8_t setterElemSize,
                                               size_t setterArraySize,
                                               const char* funcName) const {
  MOZ_ASSERT(mLinkInfo);

  if (setterArraySize == 0 || setterArraySize % setterElemSize) {
    mContext->ErrorInvalidValue(
        "%s: Expected an array of length a multiple of %d,"
        " got an array of length %zu.",
        funcName, setterElemSize, setterArraySize);
    return false;
  }

  /* GLES 2.0.25, Section 2.10, p38
   *   When loading `N` elements starting at an arbitrary position `k` in a
   * uniform declared as an array, elements `k` through `k + N - 1` in the array
   * will be replaced with the new values. Values for any array element that
   * exceeds the highest array element index used, as reported by
   * `GetActiveUniform`, will be ignored by GL.
   */
  if (!mInfo->mActiveInfo->mIsArray && setterArraySize != setterElemSize) {
    mContext->ErrorInvalidOperation(
        "%s: Expected an array of length exactly %d"
        " (since this uniform is not an array uniform),"
        " got an array of length %zu.",
        funcName, setterElemSize, setterArraySize);
    return false;
  }

  return true;
}

JS::Value WebGLUniformLocation::GetUniform(JSContext* js) const {
  MOZ_ASSERT(mLinkInfo);

  const uint8_t elemSize = mInfo->mActiveInfo->mElemSize;
  static const uint8_t kMaxElemSize = 16;
  MOZ_ASSERT(elemSize <= kMaxElemSize);

  GLuint prog = mLinkInfo->prog->mGLName;

  gl::GLContext* gl = mContext->GL();

  switch (mInfo->mActiveInfo->mElemType) {
    case LOCAL_GL_INT:
    case LOCAL_GL_INT_VEC2:
    case LOCAL_GL_INT_VEC3:
    case LOCAL_GL_INT_VEC4:
    case LOCAL_GL_SAMPLER_2D:
    case LOCAL_GL_SAMPLER_3D:
    case LOCAL_GL_SAMPLER_CUBE:
    case LOCAL_GL_SAMPLER_2D_SHADOW:
    case LOCAL_GL_SAMPLER_2D_ARRAY:
    case LOCAL_GL_SAMPLER_2D_ARRAY_SHADOW:
    case LOCAL_GL_SAMPLER_CUBE_SHADOW:
    case LOCAL_GL_INT_SAMPLER_2D:
    case LOCAL_GL_INT_SAMPLER_3D:
    case LOCAL_GL_INT_SAMPLER_CUBE:
    case LOCAL_GL_INT_SAMPLER_2D_ARRAY:
    case LOCAL_GL_UNSIGNED_INT_SAMPLER_2D:
    case LOCAL_GL_UNSIGNED_INT_SAMPLER_3D:
    case LOCAL_GL_UNSIGNED_INT_SAMPLER_CUBE:
    case LOCAL_GL_UNSIGNED_INT_SAMPLER_2D_ARRAY: {
      GLint buffer[kMaxElemSize] = {0};
      gl->fGetUniformiv(prog, mLoc, buffer);

      if (elemSize == 1) return JS::Int32Value(buffer[0]);

      JSObject* obj = dom::Int32Array::Create(js, mContext, elemSize, buffer);
      if (!obj) {
        mContext->ErrorOutOfMemory("getUniform: Out of memory.");
        return JS::NullValue();
      }
      return JS::ObjectOrNullValue(obj);
    }

    case LOCAL_GL_BOOL:
    case LOCAL_GL_BOOL_VEC2:
    case LOCAL_GL_BOOL_VEC3:
    case LOCAL_GL_BOOL_VEC4: {
      GLint buffer[kMaxElemSize] = {0};
      gl->fGetUniformiv(prog, mLoc, buffer);

      if (elemSize == 1) return JS::BooleanValue(buffer[0]);

      bool boolBuffer[kMaxElemSize];
      for (uint8_t i = 0; i < kMaxElemSize; i++) boolBuffer[i] = buffer[i];

      JS::RootedValue val(js);
      // Be careful: we don't want to convert all of |uv|!
      if (!dom::ToJSValue(js, boolBuffer, elemSize, &val)) {
        mContext->ErrorOutOfMemory("getUniform: Out of memory.");
        return JS::NullValue();
      }
      return val;
    }

    case LOCAL_GL_FLOAT:
    case LOCAL_GL_FLOAT_VEC2:
    case LOCAL_GL_FLOAT_VEC3:
    case LOCAL_GL_FLOAT_VEC4:
    case LOCAL_GL_FLOAT_MAT2:
    case LOCAL_GL_FLOAT_MAT3:
    case LOCAL_GL_FLOAT_MAT4:
    case LOCAL_GL_FLOAT_MAT2x3:
    case LOCAL_GL_FLOAT_MAT2x4:
    case LOCAL_GL_FLOAT_MAT3x2:
    case LOCAL_GL_FLOAT_MAT3x4:
    case LOCAL_GL_FLOAT_MAT4x2:
    case LOCAL_GL_FLOAT_MAT4x3: {
      GLfloat buffer[16] = {0.0f};
      gl->fGetUniformfv(prog, mLoc, buffer);

      if (elemSize == 1) return JS::DoubleValue(buffer[0]);

      JSObject* obj = dom::Float32Array::Create(js, mContext, elemSize, buffer);
      if (!obj) {
        mContext->ErrorOutOfMemory("getUniform: Out of memory.");
        return JS::NullValue();
      }
      return JS::ObjectOrNullValue(obj);
    }

    case LOCAL_GL_UNSIGNED_INT:
    case LOCAL_GL_UNSIGNED_INT_VEC2:
    case LOCAL_GL_UNSIGNED_INT_VEC3:
    case LOCAL_GL_UNSIGNED_INT_VEC4: {
      GLuint buffer[kMaxElemSize] = {0};
      gl->fGetUniformuiv(prog, mLoc, buffer);

      if (elemSize == 1)
        return JS::DoubleValue(
            buffer[0]);  // This is Double because only Int32 is special cased.

      JSObject* obj = dom::Uint32Array::Create(js, mContext, elemSize, buffer);
      if (!obj) {
        mContext->ErrorOutOfMemory("getUniform: Out of memory.");
        return JS::NullValue();
      }
      return JS::ObjectOrNullValue(obj);
    }

    default:
      MOZ_CRASH("GFX: Invalid elemType.");
  }
}

////////////////////////////////////////////////////////////////////////////////

JSObject* WebGLUniformLocation::WrapObject(JSContext* js,
                                           JS::Handle<JSObject*> givenProto) {
  return dom::WebGLUniformLocationBinding::Wrap(js, this, givenProto);
}

NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_0(WebGLUniformLocation)

NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(WebGLUniformLocation, AddRef)
NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(WebGLUniformLocation, Release)

}  // namespace mozilla