skia2/resources/slides.lua

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9.7 KiB
Lua
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gShowBounds = false
gUseBlurInTransitions = false
gPath = "resources/"
function load_file(file)
local prev_path = package.path
package.path = package.path .. ";" .. gPath .. file .. ".lua"
require(file)
package.path = prev_path
end
load_file("slides_utils")
gSlides = parse_file(io.open("resources/slides_content2.lua", "r"))
function make_rect(l, t, r, b)
return { left = l, top = t, right = r, bottom = b }
end
function make_paint(typefacename, style, size, color)
local paint = Sk.newPaint();
paint:setAntiAlias(true)
paint:setSubpixelText(true)
paint:setTypeface(Sk.newTypeface(typefacename, style))
paint:setTextSize(size)
paint:setColor(color)
return paint
end
function draw_bullet(canvas, x, y, paint, indent)
if 0 == indent then
return
end
local ps = paint:getTextSize()
local cx = x - ps * .8
local cy = y - ps * .4
local radius = ps * .2
canvas:drawCircle(cx, cy, radius, paint)
end
function stroke_rect(canvas, rect, color)
local paint = Sk.newPaint()
paint:setStroke(true);
paint:setColor(color)
canvas:drawRect(rect, paint)
end
function drawSlide(canvas, slide, master_template)
if #slide == 1 then
template = master_template.title
canvas:drawText(slide[1].text, 320, 240, template[1])
return
end
template = master_template.slide
local x = template.margin_x
local y = template.margin_y
local scale = 1.25
if slide.blockstyle == "code" then
local paint = master_template.codePaint
local fm = paint:getFontMetrics()
local height = #slide * (fm.descent - fm.ascent)
y = (480 - height) / 2
for i = 1, #slide do
local node = slide[i]
y = y - fm.ascent * scale
canvas:drawText(node.text, x, y, paint)
y = y + fm.descent * scale
end
return
end
for i = 1, #slide do
local node = slide[i]
local paint = template[node.indent + 1].paint
local extra_dy = template[node.indent + 1].extra_dy
local fm = paint:getFontMetrics()
local x_offset = -fm.ascent * node.indent * 1.25
local bounds = make_rect(x + x_offset, y, 620, 640)
local blob, newBottom = Sk.newTextBlob(node.text, bounds, paint)
draw_bullet(canvas, x + x_offset, y - fm.ascent, paint, node.indent)
canvas:drawTextBlob(blob, 0, 0, paint)
y = newBottom + paint:getTextSize() * .5 + extra_dy
if gShowBounds then
bounds.bottom = newBottom
stroke_rect(canvas, bounds, {a=1,r=0,g=1,b=0})
stroke_rect(canvas, blob:bounds(), {a=1,r=1,g=0,b=0})
end
end
end
--------------------------------------------------------------------------------------
function make_tmpl(paint, extra_dy)
return { paint = paint, extra_dy = extra_dy }
end
function SkiaPoint_make_template()
normal = Sk.newFontStyle()
bold = Sk.newFontStyle(700)
local title = {
margin_x = 30,
margin_y = 100,
}
title[1] = make_paint("Arial", bold, 45, { a=1, r=1, g=1, b=1 })
title[1]:setTextAlign("center")
title[2] = make_paint("Arial", bold, 25, { a=1, r=.75, g=.75, b=.75 })
title[2]:setTextAlign("center")
local slide = {
margin_x = 20,
margin_y = 25,
}
slide[1] = make_tmpl(make_paint("Arial", bold, 35, { a=1, r=1, g=1, b=1 }), 18)
slide[2] = make_tmpl(make_paint("Arial", normal, 25, { a=1, r=1, g=1, b=1 }), 10)
slide[3] = make_tmpl(make_paint("Arial", normal, 20, { a=1, r=.9, g=.9, b=.9 }), 5)
return {
title = title,
slide = slide,
codePaint = make_paint("Courier", normal, 20, { a=1, r=.9, g=.9, b=.9 }),
}
end
gTemplate = SkiaPoint_make_template()
gRedPaint = Sk.newPaint()
gRedPaint:setAntiAlias(true)
gRedPaint:setColor{a=1, r=1, g=0, b=0 }
-- animation.proc is passed the canvas before drawing.
-- The animation.proc returns itself or another animation (which means keep animating)
-- or it returns nil, which stops the animation.
--
local gCurrAnimation
gSlideIndex = 1
-----------------------------------------------------------------------------
function new_drawable_picture(pic)
return {
picture = pic,
width = pic:width(),
height = pic:height(),
draw = function (self, canvas, x, y, paint)
canvas:drawPicture(self.picture, x, y, paint)
end
}
end
function new_drawable_image(img)
return {
image = img,
width = img:width(),
height = img:height(),
draw = function (self, canvas, x, y, paint)
canvas:drawImage(self.image, x, y, paint)
end
}
end
function convert_to_picture_drawable(slide)
local rec = Sk.newPictureRecorder()
drawSlide(rec:beginRecording(640, 480), slide, gTemplate)
return new_drawable_picture(rec:endRecording())
end
function convert_to_image_drawable(slide)
local surf = Sk.newRasterSurface(640, 480)
drawSlide(surf:getCanvas(), slide, gTemplate)
return new_drawable_image(surf:newImageSnapshot())
end
function new_drawable_slide(slide)
return {
slide = slide,
draw = function (self, canvas, x, y, paint)
if (nil == paint or ("number" == type(paint) and (1 == paint))) then
canvas:save()
else
canvas:saveLayer(paint)
end
canvas:translate(x, y)
drawSlide(canvas, self.slide, gTemplate)
canvas:restore()
end
}
end
gNewDrawableFactory = {
default = new_drawable_slide,
picture = convert_to_picture_drawable,
image = convert_to_image_drawable,
}
-----------------------------------------------------------------------------
function next_slide()
local prev = gSlides[gSlideIndex]
if gSlideIndex < #gSlides then
gSlideIndex = gSlideIndex + 1
spawn_transition(prev, gSlides[gSlideIndex], true)
end
end
function prev_slide()
local prev = gSlides[gSlideIndex]
if gSlideIndex > 1 then
gSlideIndex = gSlideIndex - 1
spawn_transition(prev, gSlides[gSlideIndex], false)
end
end
gDrawableType = "default"
load_file("slides_transitions")
function spawn_transition(prevSlide, nextSlide, is_forward)
local transition
if is_forward then
transition = gTransitionTable[nextSlide.transition]
else
transition = gTransitionTable[prevSlide.transition]
end
if not transition then
transition = fade_slide_transition
end
local prevDrawable = gNewDrawableFactory[gDrawableType](prevSlide)
local nextDrawable = gNewDrawableFactory[gDrawableType](nextSlide)
gCurrAnimation = transition(prevDrawable, nextDrawable, is_forward)
end
--------------------------------------------------------------------------------------
function spawn_rotate_animation()
gCurrAnimation = {
angle = 0,
angle_delta = 5,
pivot_x = 320,
pivot_y = 240,
proc = function (self, canvas, drawSlideProc)
if self.angle >= 360 then
drawSlideProc(canvas)
return nil
end
canvas:translate(self.pivot_x, self.pivot_y)
canvas:rotate(self.angle)
canvas:translate(-self.pivot_x, -self.pivot_y)
drawSlideProc(canvas)
self.angle = self.angle + self.angle_delta
return self
end
}
end
function spawn_scale_animation()
gCurrAnimation = {
scale = 1,
scale_delta = .95,
scale_limit = 0.2,
pivot_x = 320,
pivot_y = 240,
proc = function (self, canvas, drawSlideProc)
if self.scale < self.scale_limit then
self.scale = self.scale_limit
self.scale_delta = 1 / self.scale_delta
end
if self.scale > 1 then
drawSlideProc(canvas)
return nil
end
canvas:translate(self.pivot_x, self.pivot_y)
canvas:scale(self.scale, self.scale)
canvas:translate(-self.pivot_x, -self.pivot_y)
drawSlideProc(canvas)
self.scale = self.scale * self.scale_delta
return self
end
}
end
local bgPaint = nil
function draw_bg(canvas)
if not bgPaint then
bgPaint = Sk.newPaint()
local grad = Sk.newLinearGradient( 0, 0, { a=1, r=0, g=0, b=.3 },
640, 480, { a=1, r=0, g=0, b=.8 })
bgPaint:setShader(grad)
bgPaint:setDither(true)
end
canvas:drawPaint(bgPaint)
end
function onDrawContent(canvas, width, height)
local matrix = Sk.newMatrix()
matrix:setRectToRect(make_rect(0, 0, 640, 480), make_rect(0, 0, width, height), "center")
canvas:concat(matrix)
draw_bg(canvas)
local drawSlideProc = function(canvas)
drawSlide(canvas, gSlides[gSlideIndex], gTemplate)
end
if gCurrAnimation then
gCurrAnimation = gCurrAnimation:proc(canvas, drawSlideProc)
return true
else
drawSlideProc(canvas)
return false
end
end
function onClickHandler(x, y)
return false
end
local keyProcs = {
n = next_slide,
p = prev_slide,
r = spawn_rotate_animation,
s = spawn_scale_animation,
["="] = function () scale_text_delta(gTemplate, 1) end,
["-"] = function () scale_text_delta(gTemplate, -1) end,
b = function () gShowBounds = not gShowBounds end,
B = function () gUseBlurInTransitions = not gUseBlurInTransitions end,
["1"] = function () gDrawableType = "default" end,
["2"] = function () gDrawableType = "picture" end,
["3"] = function () gDrawableType = "image" end,
}
function onCharHandler(uni)
local proc = keyProcs[uni]
if proc then
proc()
return true
end
return false
end