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강사님 질문있어서 문의드립니다!

21.01.01 18:09 작성 조회수 120

0

첫번째 문제

발생현상 : 새로고침 했을 경우 간혈적으로 이런 에러 문구가 출력이 됩니다. 섹션0부분에 이미지파일은 눈으로 봤을땐 정상적으로 출력된 상황입니다.

에러문구는 하단에 붙히겠습니다.

main.js:258 Uncaught TypeError: Failed to execute 'drawImage' on 'CanvasRenderingContext2D': The provided value is not of type '(CSSImageValue or HTMLImageElement or SVGImageElement or HTMLVideoElement or HTMLCanvasElement or ImageBitmap or OffscreenCanvas)'

    at playAnimation (main.js:258)

    at scrollLoop (main.js:364)

at main.js:368

두번째 문제 

발생현상 : 이것도 간혈적으로 출력되는 문제이며

main.js:352 Uncaught TypeError: Cannot read property 'scrollHeight' of undefined

    at scrollLoop (main.js:352)

    at main.js:368

이러 한 문구가 출력이 됩니다.

정말 죄송하지만 제 코드한번 봐주실수 있을까요??

(() => {
    let yOffset = 0; //window.pageYOffset 대신 쓸 변수
    let prevScrollHeight = 0; // 현재 스크롤 위치(yOffset)보다 이전에 위치한 스크롤 섹션들의 스크롤 높이값의 합
    let currentScene = 0; // 현재 활성화된(눈 앞에 보고있는) 씬(scroll-section)
    let enterNewScene = false; // 새로운 scene이 시작된 순간 true

    const sceneInfo = [{
            // 0
            type: 'sticky',
            heightNum: 5, // 브라우저 높이의 5배로 scrollHeight 세팅
            scrollHeight: 0,
            objs: {
                container: document.querySelector('#scroll-section-0'),
                messageA: document.querySelector('#scroll-section-0 .main-message.a'),
                messageB: document.querySelector('#scroll-section-0 .main-message.b'),
                messageC: document.querySelector('#scroll-section-0 .main-message.c'),
                messageD: document.querySelector('#scroll-section-0 .main-message.d'),
                canvas: document.querySelector('#video-canvas-0'),
                context: document.querySelector('#video-canvas-0').getContext('2d'),
                videoImages: []
            },
            values: {
                videoImageCount: 300,
                imageSequence: [0, 299],
                messageA_opacity_in: [0, 1, {
                    start: 0.1,
                    end: 0.2
                }],
                messageB_opacity_in: [0, 1, {
                    start: 0.3,
                    end: 0.4
                }],
                messageC_opacity_in: [0, 1, {
                    start: 0.5,
                    end: 0.6
                }],
                messageD_opacity_in: [0, 1, {
                    start: 0.7,
                    end: 0.8
                }],
                messageA_translateY_in: [20, 0, {
                    start: 0.1,
                    end: 0.2
                }],
                messageB_translateY_in: [20, 0, {
                    start: 0.3,
                    end: 0.4
                }],
                messageC_translateY_in: [20, 0, {
                    start: 0.5,
                    end: 0.6
                }],
                messageD_translateY_in: [20, 0, {
                    start: 0.7,
                    end: 0.8
                }],
                messageA_opacity_out: [1, 0, {
                    start: 0.25,
                    end: 0.3
                }],
                messageB_opacity_out: [1, 0, {
                    start: 0.45,
                    end: 0.5
                }],
                messageC_opacity_out: [1, 0, {
                    start: 0.65,
                    end: 0.7
                }],
                messageD_opacity_out: [1, 0, {
                    start: 0.85,
                    end: 0.9
                }],
                messageA_translateY_out: [0, -20, {
                    start: 0.25,
                    end: 0.3
                }],
                messageB_translateY_out: [0, -20, {
                    start: 0.45,
                    end: 0.5
                }],
                messageC_translateY_out: [0, -20, {
                    start: 0.65,
                    end: 0.7
                }],
                messageD_translateY_out: [0, -20, {
                    start: 0.85,
                    end: 0.9
                }]
            }
        },
        {
            // 1
            type: 'normal',
            // heightNum: 5, // type normal에서는 필요 없음
            scrollHeight: 0,
            objs: {
                container: document.querySelector('#scroll-section-1'),
                content: document.querySelector('#scroll-section-1 .description')
            }
        },
        {
            // 2
            type: 'sticky',
            heightNum: 5,
            scrollHeight: 0,
            objs: {
                container: document.querySelector('#scroll-section-2'),
                messageA: document.querySelector('#scroll-section-2 .a'),
                messageB: document.querySelector('#scroll-section-2 .b'),
                messageC: document.querySelector('#scroll-section-2 .c'),
                pinB: document.querySelector('#scroll-section-2 .b .pin'),
                pinC: document.querySelector('#scroll-section-2 .c .pin')
            },
            values: {
                messageA_translateY_in: [20, 0, {
                    start: 0.15,
                    end: 0.2
                }],
                messageB_translateY_in: [30, 0, {
                    start: 0.6,
                    end: 0.65
                }],
                messageC_translateY_in: [30, 0, {
                    start: 0.87,
                    end: 0.92
                }],
                messageA_opacity_in: [0, 1, {
                    start: 0.25,
                    end: 0.3
                }],
                messageB_opacity_in: [0, 1, {
                    start: 0.6,
                    end: 0.65
                }],
                messageC_opacity_in: [0, 1, {
                    start: 0.87,
                    end: 0.92
                }],
                messageA_translateY_out: [0, -20, {
                    start: 0.4,
                    end: 0.45
                }],
                messageB_translateY_out: [0, -20, {
                    start: 0.68,
                    end: 0.73
                }],
                messageC_translateY_out: [0, -20, {
                    start: 0.95,
                    end: 1
                }],
                messageA_opacity_out: [1, 0, {
                    start: 0.4,
                    end: 0.45
                }],
                messageB_opacity_out: [1, 0, {
                    start: 0.68,
                    end: 0.73
                }],
                messageC_opacity_out: [1, 0, {
                    start: 0.95,
                    end: 1
                }],
                pinB_scaleY: [0.5, 1, {
                    start: 0.6,
                    end: 0.65
                }],
                pinC_scaleY: [0.5, 1, {
                    start: 0.87,
                    end: 0.92
                }]
            }
        },
        {
            // 3
            type: 'sticky',
            heightNum: 5,
            scrollHeight: 0,
            objs: {
                container: document.querySelector('#scroll-section-3'),
                canvasCaption: document.querySelector('.canvas-caption')
            },
            values: {

            }
        }
    ];

    function setCanvasImages() {
        for (let i = 0; i < sceneInfo[0].values.videoImageCount; i++{
            imgElem = new Image();
            imgElem.src = `./video/001/IMG_${6726 + i}.JPG`;
            sceneInfo[0].objs.videoImages.push(imgElem);
        }
    }
    setCanvasImages()

    function setLayout() {

        // 각 스크롤 섹션의 높이 세팅
        for (let i = 0; i < sceneInfo.length; i++{
            if (sceneInfo[i].type === 'sticky'{
                sceneInfo[i].scrollHeight = sceneInfo[i].heightNum * window.innerHeight;
            } else if (sceneInfo[i].type === 'normal'{
                sceneInfo[i].scrollHeight = sceneInfo[i].objs.content.offsetHeight + window.innerHeight * 0.5;
            }
            sceneInfo[i].objs.container.style.height = `${sceneInfo[i].scrollHeight}px`;
        }

        yOffset = window.pageYOffset;

        let totalScrollHeight = 0;

        for (let i = 0; i < sceneInfo.length; i++{
            totalScrollHeight += sceneInfo[i].scrollHeight;
            if (totalScrollHeight >= yOffset{
                currentScene = i;
                break;
            }
        }

        document.body.setAttribute('id', `show-scene-${currentScene}`);
    }


    function calcValues(values, currentYOffset) {
        let rv;
        //현재 씬(스크롤섹션)에서 스크롤된 범위를 비율로 구하기
        const scrollHeight = sceneInfo[currentScene].scrollHeight;
        const scrollRatio = currentYOffset / scrollHeight;
        if (values.length === 3{
            //start ~ end 사이에 애니메이션 실행
            const partScrollStart = values[2].start * scrollHeight;
            const partScrollEnd = values[2].end * scrollHeight;
            const partScrollHeight = partScrollEnd - partScrollStart;
            if (currentYOffset >= partScrollStart && currentYOffset <= partScrollEnd{
                rv = (currentYOffset - partScrollStart/ partScrollHeight * (values[1- values[0]) + values[0];
            } else if (currentYOffset < partScrollStart{
                rv = values[0];
            } else if (currentYOffset > partScrollEnd{
                rv = values[1];
            }
        } else {
            rv = scrollRatio * (values[1- values[0]) + values[0];
        }
        return rv;
    }

    function playAnimation() {
        const objs = sceneInfo[currentScene].objs;
        const values = sceneInfo[currentScene].values;
        const currentYOffset = yOffset - prevScrollHeight;
        const scrollHeight = sceneInfo[currentScene].scrollHeight;
        const scrollRatio = currentYOffset / scrollHeight;

        switch (currentScene{
            case 0:
                let sequence = Math.round(calcValues(values.imageSequence, currentYOffset));
                objs.context.drawImage(objs.videoImages[sequence], 0, 0);

                if (scrollRatio <= 0.22{
                    // in
                    objs.messageA.style.opacity = calcValues(values.messageA_opacity_in, currentYOffset);
                    objs.messageA.style.transform = `translate3d(0, ${calcValues(values.messageA_translateY_in, currentYOffset)}%, 0)`;
                } else {
                    // out
                    objs.messageA.style.opacity = calcValues(values.messageA_opacity_out, currentYOffset);
                    objs.messageA.style.transform = `translate3d(0, ${calcValues(values.messageA_translateY_out, currentYOffset)}%, 0)`;
                }

                if (scrollRatio <= 0.42{
                    // in
                    objs.messageB.style.opacity = calcValues(values.messageB_opacity_in, currentYOffset);
                    objs.messageB.style.transform = `translate3d(0, ${calcValues(values.messageB_translateY_in, currentYOffset)}%, 0)`;
                } else {
                    // out
                    objs.messageB.style.opacity = calcValues(values.messageB_opacity_out, currentYOffset);
                    objs.messageB.style.transform = `translate3d(0, ${calcValues(values.messageB_translateY_out, currentYOffset)}%, 0)`;
                }

                if (scrollRatio <= 0.62{
                    // in
                    objs.messageC.style.opacity = calcValues(values.messageC_opacity_in, currentYOffset);
                    objs.messageC.style.transform = `translate3d(0, ${calcValues(values.messageC_translateY_in, currentYOffset)}%, 0)`;
                } else {
                    // out
                    objs.messageC.style.opacity = calcValues(values.messageC_opacity_out, currentYOffset);
                    objs.messageC.style.transform = `translate3d(0, ${calcValues(values.messageC_translateY_out, currentYOffset)}%, 0)`;
                }

                if (scrollRatio <= 0.82{
                    // in
                    objs.messageD.style.opacity = calcValues(values.messageD_opacity_in, currentYOffset);
                    objs.messageD.style.transform = `translate3d(0, ${calcValues(values.messageD_translateY_in, currentYOffset)}%, 0)`;
                } else {
                    // out
                    objs.messageD.style.opacity = calcValues(values.messageD_opacity_out, currentYOffset);
                    objs.messageD.style.transform = `translate3d(0, ${calcValues(values.messageD_translateY_out, currentYOffset)}%, 0)`;
                }

                break;

            case 2:
                // console.log('2 play');
                if (scrollRatio <= 0.32{
                    // in
                    objs.messageA.style.opacity = calcValues(values.messageA_opacity_in, currentYOffset);
                    objs.messageA.style.transform = `translate3d(0, ${calcValues(values.messageA_translateY_in, currentYOffset)}%, 0)`;
                } else {
                    // out
                    objs.messageA.style.opacity = calcValues(values.messageA_opacity_out, currentYOffset);
                    objs.messageA.style.transform = `translate3d(0, ${calcValues(values.messageA_translateY_out, currentYOffset)}%, 0)`;
                }

                if (scrollRatio <= 0.67{
                    // in
                    objs.messageB.style.transform = `translate3d(0, ${calcValues(values.messageB_translateY_in, currentYOffset)}%, 0)`;
                    objs.messageB.style.opacity = calcValues(values.messageB_opacity_in, currentYOffset);
                    objs.pinB.style.transform = `scaleY(${calcValues(values.pinB_scaleY, currentYOffset)})`;
                } else {
                    // out
                    objs.messageB.style.transform = `translate3d(0, ${calcValues(values.messageB_translateY_out, currentYOffset)}%, 0)`;
                    objs.messageB.style.opacity = calcValues(values.messageB_opacity_out, currentYOffset);
                    objs.pinB.style.transform = `scaleY(${calcValues(values.pinB_scaleY, currentYOffset)})`;
                }

                if (scrollRatio <= 0.93{
                    // in
                    objs.messageC.style.transform = `translate3d(0, ${calcValues(values.messageC_translateY_in, currentYOffset)}%, 0)`;
                    objs.messageC.style.opacity = calcValues(values.messageC_opacity_in, currentYOffset);
                    objs.pinC.style.transform = `scaleY(${calcValues(values.pinC_scaleY, currentYOffset)})`;
                } else {
                    // out
                    objs.messageC.style.transform = `translate3d(0, ${calcValues(values.messageC_translateY_out, currentYOffset)}%, 0)`;
                    objs.messageC.style.opacity = calcValues(values.messageC_opacity_out, currentYOffset);
                    objs.pinC.style.transform = `scaleY(${calcValues(values.pinC_scaleY, currentYOffset)})`;
                }

                break;

            case 3:
                // console.log('3 play');
                break;
        }
    }

    function scrollLoop() {
        enterNewScene = false;
        prevScrollHeight = 0;
        for (let i = 0; i < currentScene; i++{
            prevScrollHeight += sceneInfo[i].scrollHeight;
        }
        if (yOffset > prevScrollHeight + sceneInfo[currentScene].scrollHeight{
            enterNewScene = true;
            currentScene++;
            document.body.setAttribute('id', `show-scene-${currentScene}`);
        }
        if (yOffset < prevScrollHeight{
            if (currentScene === 0return // 브라우저 바운스 효과로 인해 마이너스가 되는 것을 방지(모바일)
            enterNewScene = true;
            currentScene--;
            document.body.setAttribute('id', `show-scene-${currentScene}`);
        }
        if (enterNewScenereturn;
        playAnimation();
    }
    window.addEventListener('scroll', () => {
        yOffset = window.pageYOffset;
        scrollLoop();
    });
    //window.addEventListener('DOMContentLoaded', setLayout);
    window.addEventListener('load', setLayout);
    window.addEventListener('resize', setLayout);



})();

답변 2

·

답변을 작성해보세요.

0

mario213님의 프로필

mario213

질문자

2021.01.10

이번에도 친절한 답변 감사합니다! 음 답변내용으로 고쳐봤는데 아직까지는 그런 현상은 발생하지 않습니다!
저 현상이 이미지로드가 다 안됐을때 발생하는듯해요! 우선 나머지 강의 열심히 듣도록 하겠습니다!

0

답이 조금 시간이 걸렸네요~ 제가 체크해보니 작성하신 소스에 특별히 이상은 보이지 않는데, 혹시 지금도 해결이 안되었나요?
캔버스로 처리하는 부분은 뒤쪽 파트에 가면 좀 변경이 되는데, 그때 자연스럽게 해결이 될 수도 있을 것 같습니다.
참고로 말씀하신 오류는, drawImage에 그려질 소스가 잘못 제공되면 발생하는데요, 제일 흔한 경우가 이미지의 경로를 잘못 쓰거나 이미지의 확장자가 .JPG인데 .jpg로 쓰는 등 잘못 썼을 경우입니다.

두번째는 sceneInfo[currentScene]의 값을 제대로 못가져와서 발생하는 버그인데, currentScene의 값이 잘못 들어갔을 경우로 생각됩니다.

if (currentScene === 0) return // 브라우저 바운스 효과로 인해 마이너스가 되는 것을 방지(모바일)
enterNewScene = true;

이 부분의 순서가 강의에서 작성하는 코드랑 다른데요, enterNewScene이 true가 되기 전에 리턴이 되어 문제가 생겼을 수 있을 것 같아요. 이 부분을

enterNewScene = true;
if
(currentScene === 0) return // 브라우저 바운스 효과로 인해 마이너스가 되는 것을 방지(모바일)

이렇게 한번 바꾸어보세요~