diff options
| -rw-r--r-- | README.md | 13 | ||||
| -rw-r--r-- | js/reveal.js | 38 |
2 files changed, 41 insertions, 10 deletions
@@ -175,6 +175,10 @@ Reveal.initialize({ // Parallax background size parallaxBackgroundSize: '' // CSS syntax, e.g. "2100px 900px" + // Amount to move parallax background (horizontal and vertical) on slide change + // Number, e.g. 100 + parallaxBackgroundHorizontal: '', + parallaxBackgroundVertical: '' }); ``` @@ -440,7 +444,7 @@ Backgrounds transition using a fade animation by default. This can be changed to ### Parallax Background -If you want to use a parallax scrolling background, set the two following config properties when initializing reveal.js (the third one is optional). +If you want to use a parallax scrolling background, set the first two config properties below when initializing reveal.js (the other two are optional). ```javascript Reveal.initialize({ @@ -451,8 +455,11 @@ Reveal.initialize({ // Parallax background size parallaxBackgroundSize: '', // CSS syntax, e.g. "2100px 900px" - currently only pixels are supported (don't use % or auto) - // This slide transition gives best results: - transition: 'slide' + // Amount of pixels to move the parallax background per slide step, + // a value of 0 disables movement along the given axis + // These are optional, if they aren't specified they'll be calculated automatically + parallaxBackgroundHorizontal: 200, + parallaxBackgroundVertical: 50 }); ``` diff --git a/js/reveal.js b/js/reveal.js index 3c06f8d..0e60745 100644 --- a/js/reveal.js +++ b/js/reveal.js @@ -136,6 +136,10 @@ // Parallax background size parallaxBackgroundSize: '', // CSS syntax, e.g. "3000px 2000px" + // Amount of pixels to move the parallax background per slide step + parallaxBackgroundHorizontal: null, + parallaxBackgroundVertical: null, + // Number of slides away from the current that are visible viewDistance: 3, @@ -2672,15 +2676,35 @@ backgroundHeight = parseInt( backgroundSize[1], 10 ); } - var slideWidth = dom.background.offsetWidth; - var horizontalSlideCount = horizontalSlides.length; - var horizontalOffset = -( backgroundWidth - slideWidth ) / ( horizontalSlideCount-1 ) * indexh; + var slideWidth = dom.background.offsetWidth, + horizontalSlideCount = horizontalSlides.length, + horizontalOffsetMultiplier, + horizontalOffset; + + if( typeof config.parallaxBackgroundHorizontal === 'number' ) { + horizontalOffsetMultiplier = config.parallaxBackgroundHorizontal; + } + else { + horizontalOffsetMultiplier = ( backgroundWidth - slideWidth ) / ( horizontalSlideCount-1 ); + } + + horizontalOffset = horizontalOffsetMultiplier * indexh * -1; + + var slideHeight = dom.background.offsetHeight, + verticalSlideCount = verticalSlides.length, + verticalOffsetMultiplier, + verticalOffset; + + if( typeof config.parallaxBackgroundVertical === 'number' ) { + verticalOffsetMultiplier = config.parallaxBackgroundVertical; + } + else { + verticalOffsetMultiplier = ( backgroundHeight - slideHeight ) / ( verticalSlideCount-1 ); + } - var slideHeight = dom.background.offsetHeight; - var verticalSlideCount = verticalSlides.length; - var verticalOffset = verticalSlideCount > 1 ? -( backgroundHeight - slideHeight ) / ( verticalSlideCount-1 ) * indexv : 0; + verticalOffset = verticalSlideCount > 0 ? verticalOffsetMultiplier * indexv * 1 : 0; - dom.background.style.backgroundPosition = horizontalOffset + 'px ' + verticalOffset + 'px'; + dom.background.style.backgroundPosition = horizontalOffset + 'px ' + -verticalOffset + 'px'; } |