update slide content

BUG=skia:
TBR=

Review URL: https://codereview.chromium.org/698563004

resources/slides.lua

@@ -27,6 +27,32 @@ function make_paint(typefacename, stylebits, size, color)
     return paint
 end
 
+function center_rect(sw, sh, dst)
+    local dw = dst.right - dst.left
+    local dh = dst.bottom - dst.top
+
+    local rw, rh
+
+    if sw / sh > dw / dh then
+        rw = dw
+        rh = sh * dw / sw
+    else
+        rh = dh
+        rw = sw * dh / sh
+    end
+
+    local x = dst.left + ((sw - rw) / 2)
+    local y = dst.top  + ((sh - rh) / 2)
+    return make_rect(x, y, x + rw, y + rh)
+end
+
+function draw_image_centered(canvas, image)
+    local sw = image:width()
+    local sh = image:height()
+    local dstR = center_rect(image:width(), image:height(), make_rect(20, 20, 620, 460))
+    canvas:drawImageRect(image, nil, dstR)
+end
+
 function draw_bullet(canvas, x, y, paint, indent)
     if 0 == indent then
         return
@@ -46,7 +72,14 @@ function stroke_rect(canvas, rect, color)
 end
 
 function drawSlide(canvas, slide, master_template)
-    template = master_template.slide   -- need to sniff the slide to know if we're title or slide
+
+    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
@@ -173,23 +206,19 @@ end
 function next_slide()
     local prev = gSlides[gSlideIndex]
 
-    gSlideIndex = gSlideIndex + 1
+    if gSlideIndex < #gSlides then
-    if gSlideIndex > #gSlides then
+        gSlideIndex = gSlideIndex + 1
-        gSlideIndex = 1
+        spawn_transition(prev, gSlides[gSlideIndex], true)
     end
-
-    spawn_transition(prev, gSlides[gSlideIndex], true)
 end
 
 function prev_slide()
     local prev = gSlides[gSlideIndex]
 
-    gSlideIndex = gSlideIndex - 1
+    if gSlideIndex > 1 then
-    if gSlideIndex < 1 then
+        gSlideIndex = gSlideIndex - 1
-        gSlideIndex = #gSlides
+        spawn_transition(prev, gSlides[gSlideIndex], false)
     end
-
-    spawn_transition(prev, gSlides[gSlideIndex], false)
 end
 
 function convert_to_picture_drawable(slide)
@@ -204,7 +233,6 @@ function convert_to_image_drawable(slide)
     return new_drawable_image(surf:newImageSnapshot())
 end
 
--- gMakeDrawable = convert_to_picture_drawable
 gMakeDrawable = new_drawable_slide
 
 load_file("slides_transitions")
@@ -285,6 +313,7 @@ function draw_bg(canvas)
         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)

resources/slides_content2.lua

@@ -2,80 +2,29 @@ Skia Update
 
 Skia : Overview
 - portable 2D graphics engine
-- src: geometry, images, text
+- src : geometry, images, text
-- dst : raster, gpu, pdf, displaylist, *user-defined
+- attr: shaders, filters, antialiasing, blending
-- attr: shaders, filters, antialiasing, blending, *user-defined
+- dst : raster, gpu, pdf, picture
-
-Skia : Clients
-- Blink : direct and via GraphicsContext
-- Chrome : ui/gfx and compositor
-- Android framework
-- third parties : e.g. Mozilla
-- code.google.com/p/skia
 
 Skia : Porting
 - C++ and some SIMD assembly
-- Fonts : CoreText, FreeType, GDI, DirectWrite, *user-define
+- Fonts : CoreText, FreeType, GDI, DirectWrite
 - Threads : wrappers for native apis
 - Memory : wrappers for [new, malloc, discardable]
 
-Skia : API
+Skia : Clients
-- SkCanvas
+- Blink : under the GraphicsContext hood
--- save, saveLayer, restore
+- Chrome : ui/gfx and compositor
--- translate, scale, rotate, concat
+- Android framework
--- clipRect, clipPath
+- third parties : e.g. Mozilla
-- SkPaint
+- sites.google.com/site/skiadocs
--- color, stroking, antialiasing, filtering
--- typeface, textSize, text-flags
--- effects: shader, color-filter, image-filter, mask-filter, xfermode
 
-<blockstyle = code>
+Skia In Blink
-void onDraw(SkCanvas* canvas) {
-    SkPaint paint;
-    paint.setFoo(...);
-    canvas->drawRect(..., paint);
-    paint.setBar(...);
-    canvas->drawOval(..., paint);
-}
-
-<blockstyle = code>
-void onDraw(SkCanvas* canvas) {
-    canvas->drawRect(..., fPaint0);
-    canvas->drawOval(..., fPaint1);
-}
-
-Skia In Blink : GraphicsContext
-- Similar
--- rects, paths, images, text
--- matrices, clips
-- Different
--- save/restore affect matrix+clip PLUS all paint settings
--- both fill and stroke settings are specified
--- hence: fillRect(), strokeRect(), drawRect()
-
-<blockstyle = code>
-void onDraw(GraphicsContext* gc) {
-    gc->save();
-    gc->setFoo(...);
-    gc->fillRect(...);
-    gc->setBar(...);
-    gc->fillOval(...);
-    gc->restore();
-}
-
-Skia In Blink : more than GraphicsContext
-- Simple wrappers
--- FloatRect -- SkRect
--- Path -- SkPath
-- Font.h + 21 others
--- SkTypeface + flags
-- Image.h + 25 others
--- SkBitmap, SkImage
 
 Skia In Blink : Fonts
-- Assist with code-sharing between platforms
+- SkTypeface and SkFontMgr : platform agnostic
 - Runtime switch between GDI and DirectWrite
-- Add SkFontMgr for selection
+- SkTextBlob to encapsulate runs of text
 - Push LCD decision-making out of Blink
 
 Skia In Blink : Record-Time-Rasterization
@@ -89,8 +38,52 @@ Skia In Blink : Record-Time-Rasterization
 
 Skia In Blink : RTR response
 - SkImageFilter w/ CPU and GPU implementations
-- SkPaint::FilterLevel : none, low, medium (mipmaps), high
+- FilterLevel : none, low, medium (mipmaps), high
 - SkPicture for caching SVG
 - SkPicture + saveLayer() for masks
 -- PathOps for resolving complex paths
 - SkPictureShader for device-independent patterns
+
+Skia In Blink : Recording
+- GraphicsContext usuaually backed by SkPicture
+-- draw commands are recorded for later playback
+-- all parameters must be copied or (safely) ref'd
+-- may record more than is currently visible
+- Resulting picture may be replayed multiple times
+
+Skia In Blink : Recording response
+- New implementation
+- Optimized for recording speed
+-- shallow copies whenever possible
+-- rearchitect all Skia effects to be immutable
+- Reentrant-safe for playback in multiple threads
+-- also affected effect subclasses
+
+Skia In Blink : Playback
+- Separate pass for optimizations (optional)
+-- peep-holes rewrites
+-- compute bounding-box hierarchy for faster tiling
+-- can be done outside of Blink thread
+- GPU optimizations
+-- layer "hoisting"
+-- distance field fonts
+
+Skia : Roadmap
+
+Skia In Blink : Roadmap
+- GPU performance
+-- extended OpenGL features (e.g. geometry shaders)
+-- reordering for increased batching
+-- support for new low-level OpenGL APIs
+- Cross process support
+-- immediate mode ala SkGPipe
+-- serialize pictures
+
+Skia API Roadmap
+- Direct support for sRGB
+- Stable C API / ABI
+-- bindings for JS, Go, Python, Lua
+- Robust file format
+
+Demo
+

resources/slides_utils.lua

@@ -54,12 +54,17 @@ function pretty_print_slides(slides)
     io.write("}\n")
 end
 
-function parse_transition_type(s)
+function parse_attr(s, lvalue)
-    return s:match("^<%s*transition%s*=%s*(%a+)%s*>$")
+    local ts = "^<%s*" .. lvalue .. "%s*=%s*(%a+)%s*>$"
+    return s:match(ts)
 end
 
-function parse_blockstyle_type(s)
+function flush(slides, block)
-    return s:match("^<%s*blockstyle%s*=%s*(%a+)%s*>$")
+    if #block > 0 then
+        slides[#slides + 1] = block
+        return {}
+    end
+    return block
 end
 
 function parse_file(file)
@@ -69,13 +74,10 @@ function parse_file(file)
     for line in file:lines() do
         local s = trim_ws(line)
         if #s == 0 then   -- done with a block
-            if #block > 0 then
+            block = flush(slides, block)
-                slides[#slides + 1] = block
-                block = {}
-            end
         else
-            local transition_type = parse_transition_type(s)
+            local transition_type = parse_attr(s, "transition")
-            local blockstyle = parse_blockstyle_type(s)
+            local blockstyle = parse_attr(s, "blockstyle")
             if transition_type then
                 block["transition"] = transition_type
             elseif blockstyle then

src/utils/SkLua.cpp

@@ -761,6 +761,11 @@ static int lpaint_isDither(lua_State* L) {
     return 1;
 }
 
+static int lpaint_setDither(lua_State* L) {
+    get_obj<SkPaint>(L, 1)->setDither(lua2bool(L, 2));
+    return 0;
+}
+
 static int lpaint_isUnderlineText(lua_State* L) {
     lua_pushboolean(L, get_obj<SkPaint>(L, 1)->isUnderlineText());
     return 1;
@@ -1061,6 +1066,7 @@ static const struct luaL_Reg gSkPaint_Methods[] = {
     { "isAntiAlias", lpaint_isAntiAlias },
     { "setAntiAlias", lpaint_setAntiAlias },
     { "isDither", lpaint_isDither },
+    { "setDither", lpaint_setDither },
     { "isUnderlineText", lpaint_isUnderlineText },
     { "isStrikeThruText", lpaint_isStrikeThruText },
     { "isFakeBoldText", lpaint_isFakeBoldText },