/* -*- 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,
                                           GLuint loc, const WebGLActiveInfo* activeInfo)
    : WebGLContextBoundObject(webgl)
    , mLinkInfo(linkInfo)
    , mLoc(loc)
    , mActiveInfo(activeInfo)
{ }

WebGLUniformLocation::~WebGLUniformLocation()
{ }

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ErrorInvalidOperation("%s: This uniform location is obsolete because its"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

    if (mLinkInfo->prog != prog) {
        webgl->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("Bad `uniformType`.");
    }
}

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

    if (setterElemSize != mActiveInfo->mElemSize) {
        webgl->ErrorInvalidOperation("%s: Bad uniform size: %i", funcName,
                                     mActiveInfo->mElemSize);
        return false;
    }

    if (!IsUniformSetterTypeValid(setterType, mActiveInfo->mElemType)) {
        webgl->ErrorInvalidOperation("%s: Bad uniform type: %i", funcName,
                                     mActiveInfo->mElemSize);
        return false;
    }

    return true;
}

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

    if (setterArraySize == 0 ||
        setterArraySize % setterElemSize)
    {
        webgl->ErrorInvalidValue("%s: expected an array of length a multiple of"
                                 " %d, got an array of length %d.",
                                 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 (!mActiveInfo->mIsArray &&
        setterArraySize != setterElemSize)
    {
        webgl->ErrorInvalidOperation("%s: expected an array of length exactly %d"
                                     " (since this uniform is not an array"
                                     " uniform), got an array of length %d.",
                                     funcName, setterElemSize, setterArraySize);
        return false;
    }

    return true;
}

bool
WebGLUniformLocation::ValidateSamplerSetter(GLint value, WebGLContext* webgl,
                                            const char* funcName) const
{
    MOZ_ASSERT(mLinkInfo);

    if (mActiveInfo->mElemType != LOCAL_GL_SAMPLER_2D &&
        mActiveInfo->mElemType != LOCAL_GL_SAMPLER_CUBE)
    {
        return true;
    }

    if (value >= 0 && value < (GLint)webgl->GLMaxTextureUnits())
        return true;

    webgl->ErrorInvalidValue("%s: This uniform location is a sampler, but %d is not a"
                             " valid texture unit.",
                             funcName, value);
    return false;
}

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

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

    GLuint prog = mLinkInfo->prog->mGLName;

    gl::GLContext* gl = webgl->GL();
    gl->MakeCurrent();

    switch (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_CUBE:
        {
            GLint buffer[kMaxElemSize] = {0};
            gl->fGetUniformiv(prog, mLoc, buffer);

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

            JSObject* obj = dom::Int32Array::Create(js, webgl, elemSize, buffer);
            if (!obj) {
                webgl->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)) {
                webgl->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:
        {
            GLfloat buffer[16] = {0.0f};
            gl->fGetUniformfv(prog, mLoc, buffer);

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

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

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

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

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

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