diff --git a/spec/fake-lines-yardstick.coffee b/spec/fake-lines-yardstick.coffee
index 3d2ebe7d5..a8a624970 100644
--- a/spec/fake-lines-yardstick.coffee
+++ b/spec/fake-lines-yardstick.coffee
@@ -31,7 +31,7 @@ class FakeLinesYardstick
     targetColumn = screenPosition.column
     baseCharacterWidth = @model.getDefaultCharWidth()
 
-    top = @lineTopIndex.bottomPixelPositionForRow(targetRow)
+    top = @lineTopIndex.pixelPositionForRow(targetRow)
     left = 0
     column = 0
 
@@ -61,14 +61,14 @@ class FakeLinesYardstick
     {top, left}
 
   pixelRectForScreenRange: (screenRange) ->
+    top = @lineTopIndex.pixelPositionForRow(screenRange.start.row)
     if screenRange.end.row > screenRange.start.row
-      top = @pixelPositionForScreenPosition(screenRange.start).top
       left = 0
-      height = @lineTopIndex.topPixelPositionForRow(screenRange.end.row + 1) - top
+      height = @lineTopIndex.pixelPositionForRow(screenRange.end.row) - top + @model.getLineHeightInPixels()
       width = @presenter.getScrollWidth()
     else
-      {top, left} = @pixelPositionForScreenPosition(screenRange.start, false)
-      height = @lineTopIndex.topPixelPositionForRow(screenRange.end.row + 1) - top
+      {left} = @pixelPositionForScreenPosition(screenRange.start, false)
+      height = @lineTopIndex.pixelPositionForRow(screenRange.end.row) - top + @model.getLineHeightInPixels()
       width = @pixelPositionForScreenPosition(screenRange.end, false).left - left
 
     {top, left, width, height}
diff --git a/spec/line-top-index-spec.js b/spec/line-top-index-spec.js
deleted file mode 100644
index 62d3e1839..000000000
--- a/spec/line-top-index-spec.js
+++ /dev/null
@@ -1,189 +0,0 @@
-/** @babel */
-
-const LineTopIndex = require('../src/linear-line-top-index')
-
-describe("LineTopIndex", function () {
-  let lineTopIndex
-
-  beforeEach(function () {
-    lineTopIndex = new LineTopIndex()
-    lineTopIndex.setDefaultLineHeight(10)
-    lineTopIndex.setMaxRow(12)
-  })
-
-  describe("::topPixelPositionForRow(row)", function () {
-    it("performs the simple math when there are no block decorations", function () {
-      expect(lineTopIndex.topPixelPositionForRow(0)).toBe(0)
-      expect(lineTopIndex.topPixelPositionForRow(4)).toBe(40)
-      expect(lineTopIndex.topPixelPositionForRow(5)).toBe(50)
-      expect(lineTopIndex.topPixelPositionForRow(12)).toBe(120)
-      expect(lineTopIndex.topPixelPositionForRow(13)).toBe(120)
-      expect(lineTopIndex.topPixelPositionForRow(14)).toBe(120)
-
-      lineTopIndex.splice(0, 2, 3)
-
-      expect(lineTopIndex.topPixelPositionForRow(0)).toBe(0)
-      expect(lineTopIndex.topPixelPositionForRow(4)).toBe(40)
-      expect(lineTopIndex.topPixelPositionForRow(5)).toBe(50)
-      expect(lineTopIndex.topPixelPositionForRow(12)).toBe(120)
-      expect(lineTopIndex.topPixelPositionForRow(13)).toBe(130)
-      expect(lineTopIndex.topPixelPositionForRow(14)).toBe(130)
-    })
-
-    it("takes into account inserted and removed blocks", function () {
-      let block1 = lineTopIndex.insertBlock(0, 10)
-      let block2 = lineTopIndex.insertBlock(3, 20)
-      let block3 = lineTopIndex.insertBlock(5, 20)
-
-      expect(lineTopIndex.topPixelPositionForRow(0)).toBe(0)
-      expect(lineTopIndex.topPixelPositionForRow(1)).toBe(20)
-      expect(lineTopIndex.topPixelPositionForRow(2)).toBe(30)
-      expect(lineTopIndex.topPixelPositionForRow(3)).toBe(40)
-      expect(lineTopIndex.topPixelPositionForRow(4)).toBe(70)
-      expect(lineTopIndex.topPixelPositionForRow(5)).toBe(80)
-      expect(lineTopIndex.topPixelPositionForRow(6)).toBe(110)
-
-      lineTopIndex.removeBlock(block1)
-      lineTopIndex.removeBlock(block3)
-
-      expect(lineTopIndex.topPixelPositionForRow(0)).toBe(0)
-      expect(lineTopIndex.topPixelPositionForRow(1)).toBe(10)
-      expect(lineTopIndex.topPixelPositionForRow(2)).toBe(20)
-      expect(lineTopIndex.topPixelPositionForRow(3)).toBe(30)
-      expect(lineTopIndex.topPixelPositionForRow(4)).toBe(60)
-      expect(lineTopIndex.topPixelPositionForRow(5)).toBe(70)
-      expect(lineTopIndex.topPixelPositionForRow(6)).toBe(80)
-    })
-
-    it("moves blocks down/up when splicing regions", function () {
-      let block1 = lineTopIndex.insertBlock(3, 20)
-      let block2 = lineTopIndex.insertBlock(5, 30)
-
-      lineTopIndex.splice(0, 0, 4)
-
-      expect(lineTopIndex.topPixelPositionForRow(0)).toBe(0)
-      expect(lineTopIndex.topPixelPositionForRow(6)).toBe(60)
-      expect(lineTopIndex.topPixelPositionForRow(7)).toBe(70)
-      expect(lineTopIndex.topPixelPositionForRow(8)).toBe(100)
-      expect(lineTopIndex.topPixelPositionForRow(9)).toBe(110)
-      expect(lineTopIndex.topPixelPositionForRow(10)).toBe(150)
-      expect(lineTopIndex.topPixelPositionForRow(11)).toBe(160)
-
-      lineTopIndex.splice(0, 6, 2)
-
-      expect(lineTopIndex.topPixelPositionForRow(0)).toBe(0)
-      expect(lineTopIndex.topPixelPositionForRow(3)).toBe(30)
-      expect(lineTopIndex.topPixelPositionForRow(4)).toBe(60)
-      expect(lineTopIndex.topPixelPositionForRow(5)).toBe(70)
-      expect(lineTopIndex.topPixelPositionForRow(6)).toBe(110)
-
-      lineTopIndex.splice(2, 4, 0)
-
-      expect(lineTopIndex.topPixelPositionForRow(0)).toBe(0)
-      expect(lineTopIndex.topPixelPositionForRow(1)).toBe(10)
-      expect(lineTopIndex.topPixelPositionForRow(2)).toBe(20)
-      expect(lineTopIndex.topPixelPositionForRow(3)).toBe(80)
-      expect(lineTopIndex.topPixelPositionForRow(4)).toBe(90)
-      expect(lineTopIndex.topPixelPositionForRow(5)).toBe(100)
-      expect(lineTopIndex.topPixelPositionForRow(6)).toBe(110)
-      expect(lineTopIndex.topPixelPositionForRow(7)).toBe(120)
-      expect(lineTopIndex.topPixelPositionForRow(8)).toBe(130)
-      expect(lineTopIndex.topPixelPositionForRow(9)).toBe(130)
-    })
-  })
-
-  describe("::rowForTopPixelPosition(top)", function () {
-    it("performs the simple math when there are no block decorations", function () {
-      expect(lineTopIndex.rowForTopPixelPosition(0)).toBe(0)
-      expect(lineTopIndex.rowForTopPixelPosition(40)).toBe(4)
-      expect(lineTopIndex.rowForTopPixelPosition(44)).toBe(4)
-      expect(lineTopIndex.rowForTopPixelPosition(46)).toBe(4)
-      expect(lineTopIndex.rowForTopPixelPosition(50)).toBe(5)
-      expect(lineTopIndex.rowForTopPixelPosition(120)).toBe(12)
-      expect(lineTopIndex.rowForTopPixelPosition(130)).toBe(12)
-      expect(lineTopIndex.rowForTopPixelPosition(140)).toBe(12)
-      expect(lineTopIndex.rowForTopPixelPosition(145)).toBe(12)
-
-      lineTopIndex.splice(0, 2, 3)
-
-      expect(lineTopIndex.rowForTopPixelPosition(0)).toBe(0)
-      expect(lineTopIndex.rowForTopPixelPosition(40)).toBe(4)
-      expect(lineTopIndex.rowForTopPixelPosition(50)).toBe(5)
-      expect(lineTopIndex.rowForTopPixelPosition(120)).toBe(12)
-      expect(lineTopIndex.rowForTopPixelPosition(130)).toBe(13)
-      expect(lineTopIndex.rowForTopPixelPosition(140)).toBe(13)
-    })
-
-    it("takes into account inserted and removed blocks", function () {
-      let block1 = lineTopIndex.insertBlock(0, 10)
-      let block2 = lineTopIndex.insertBlock(3, 20)
-      let block3 = lineTopIndex.insertBlock(5, 20)
-
-      expect(lineTopIndex.rowForTopPixelPosition(0)).toBe(0)
-      expect(lineTopIndex.rowForTopPixelPosition(6)).toBe(0)
-      expect(lineTopIndex.rowForTopPixelPosition(10)).toBe(0)
-      expect(lineTopIndex.rowForTopPixelPosition(12)).toBe(0)
-      expect(lineTopIndex.rowForTopPixelPosition(17)).toBe(0)
-      expect(lineTopIndex.rowForTopPixelPosition(20)).toBe(1)
-      expect(lineTopIndex.rowForTopPixelPosition(30)).toBe(2)
-      expect(lineTopIndex.rowForTopPixelPosition(40)).toBe(3)
-      expect(lineTopIndex.rowForTopPixelPosition(70)).toBe(4)
-      expect(lineTopIndex.rowForTopPixelPosition(80)).toBe(5)
-      expect(lineTopIndex.rowForTopPixelPosition(90)).toBe(5)
-      expect(lineTopIndex.rowForTopPixelPosition(95)).toBe(5)
-      expect(lineTopIndex.rowForTopPixelPosition(106)).toBe(5)
-      expect(lineTopIndex.rowForTopPixelPosition(110)).toBe(6)
-      expect(lineTopIndex.rowForTopPixelPosition(160)).toBe(11)
-      expect(lineTopIndex.rowForTopPixelPosition(166)).toBe(11)
-      expect(lineTopIndex.rowForTopPixelPosition(170)).toBe(12)
-      expect(lineTopIndex.rowForTopPixelPosition(240)).toBe(12)
-
-      lineTopIndex.removeBlock(block1)
-      lineTopIndex.removeBlock(block3)
-
-      expect(lineTopIndex.rowForTopPixelPosition(0)).toBe(0)
-      expect(lineTopIndex.rowForTopPixelPosition(10)).toBe(1)
-      expect(lineTopIndex.rowForTopPixelPosition(20)).toBe(2)
-      expect(lineTopIndex.rowForTopPixelPosition(30)).toBe(3)
-      expect(lineTopIndex.rowForTopPixelPosition(60)).toBe(4)
-      expect(lineTopIndex.rowForTopPixelPosition(70)).toBe(5)
-      expect(lineTopIndex.rowForTopPixelPosition(80)).toBe(6)
-    })
-
-    it("moves blocks down/up when splicing regions", function () {
-      let block1 = lineTopIndex.insertBlock(3, 20)
-      let block2 = lineTopIndex.insertBlock(5, 30)
-
-      lineTopIndex.splice(0, 0, 4)
-
-      expect(lineTopIndex.rowForTopPixelPosition(0)).toBe(0)
-      expect(lineTopIndex.rowForTopPixelPosition(60)).toBe(6)
-      expect(lineTopIndex.rowForTopPixelPosition(70)).toBe(7)
-      expect(lineTopIndex.rowForTopPixelPosition(100)).toBe(8)
-      expect(lineTopIndex.rowForTopPixelPosition(110)).toBe(9)
-      expect(lineTopIndex.rowForTopPixelPosition(150)).toBe(10)
-      expect(lineTopIndex.rowForTopPixelPosition(160)).toBe(11)
-
-      lineTopIndex.splice(0, 6, 2)
-
-      expect(lineTopIndex.rowForTopPixelPosition(0)).toBe(0)
-      expect(lineTopIndex.rowForTopPixelPosition(30)).toBe(3)
-      expect(lineTopIndex.rowForTopPixelPosition(60)).toBe(4)
-      expect(lineTopIndex.rowForTopPixelPosition(70)).toBe(5)
-      expect(lineTopIndex.rowForTopPixelPosition(110)).toBe(6)
-
-      lineTopIndex.splice(2, 4, 0)
-
-      expect(lineTopIndex.rowForTopPixelPosition(0)).toBe(0)
-      expect(lineTopIndex.rowForTopPixelPosition(10)).toBe(1)
-      expect(lineTopIndex.rowForTopPixelPosition(20)).toBe(2)
-      expect(lineTopIndex.rowForTopPixelPosition(80)).toBe(3)
-      expect(lineTopIndex.rowForTopPixelPosition(90)).toBe(4)
-      expect(lineTopIndex.rowForTopPixelPosition(100)).toBe(5)
-      expect(lineTopIndex.rowForTopPixelPosition(110)).toBe(6)
-      expect(lineTopIndex.rowForTopPixelPosition(120)).toBe(7)
-      expect(lineTopIndex.rowForTopPixelPosition(130)).toBe(8)
-      expect(lineTopIndex.rowForTopPixelPosition(130)).toBe(8)
-    })
-  })
-})
diff --git a/spec/lines-yardstick-spec.coffee b/spec/lines-yardstick-spec.coffee
index 44267699e..791385d64 100644
--- a/spec/lines-yardstick-spec.coffee
+++ b/spec/lines-yardstick-spec.coffee
@@ -57,9 +57,10 @@ describe "LinesYardstick", ->
           textNodes
 
       editor.setLineHeightInPixels(14)
-      lineTopIndex = new LineTopIndex()
-      lineTopIndex.setDefaultLineHeight(editor.getLineHeightInPixels())
-      lineTopIndex.setMaxRow(editor.getScreenLineCount())
+      lineTopIndex = new LineTopIndex({
+        maxRow: editor.getScreenLineCount(),
+        defaultLineHeight: editor.getLineHeightInPixels()
+      })
       linesYardstick = new LinesYardstick(editor, mockPresenter, mockLineNodesProvider, lineTopIndex, atom.grammars)
 
   afterEach ->
diff --git a/spec/text-editor-presenter-spec.coffee b/spec/text-editor-presenter-spec.coffee
index fdcb8a418..87c32475d 100644
--- a/spec/text-editor-presenter-spec.coffee
+++ b/spec/text-editor-presenter-spec.coffee
@@ -27,7 +27,10 @@ describe "TextEditorPresenter", ->
       buffer.destroy()
 
     buildPresenterWithoutMeasurements = (params={}) ->
-      lineTopIndex = new LineTopIndex
+      lineTopIndex = new LineTopIndex({
+        maxRow: editor.getScreenLineCount(),
+        defaultLineHeight: editor.getLineHeightInPixels()
+      })
       _.defaults params,
         model: editor
         config: atom.config
@@ -526,8 +529,6 @@ describe "TextEditorPresenter", ->
           presenter = buildPresenter(scrollTop: 0, lineHeight: 10)
           expect(presenter.getState().verticalScrollbar.scrollHeight).toBe editor.getScreenLineCount() * 10
 
-          # Setting `null` as the DOM element, as it doesn't really matter here.
-          # Maybe a signal that we should separate models from views?
           blockDecoration1 = editor.addBlockDecorationForScreenRow(0, null)
           blockDecoration2 = editor.addBlockDecorationForScreenRow(3, null)
           blockDecoration3 = editor.addBlockDecorationForScreenRow(7, null)
@@ -719,8 +720,6 @@ describe "TextEditorPresenter", ->
           presenter = buildPresenter(scrollTop: 0, lineHeight: 10)
           expect(presenter.getState().verticalScrollbar.scrollHeight).toBe editor.getScreenLineCount() * 10
 
-          # Setting `null` as the DOM element, as it doesn't really matter here.
-          # Maybe a signal that we should separate models from views?
           blockDecoration1 = editor.addBlockDecorationForScreenRow(0, null)
           blockDecoration2 = editor.addBlockDecorationForScreenRow(3, null)
           blockDecoration3 = editor.addBlockDecorationForScreenRow(7, null)
@@ -3041,8 +3040,8 @@ describe "TextEditorPresenter", ->
             presenter.setBlockDecorationDimensions(blockDecoration3, 0, 7)
 
             decorationState = getContentForGutterWithName(presenter, 'test-gutter')
-            expect(decorationState[decoration1.id].top).toBe lineHeight * marker1.getScreenRange().start.row
-            expect(decorationState[decoration1.id].height).toBe lineHeight * marker1.getScreenRange().getRowCount() + 3
+            expect(decorationState[decoration1.id].top).toBe lineHeight * marker1.getScreenRange().start.row + 3
+            expect(decorationState[decoration1.id].height).toBe lineHeight * marker1.getScreenRange().getRowCount()
             expect(decorationState[decoration1.id].item).toBe decorationItem
             expect(decorationState[decoration1.id].class).toBe 'test-class'
             expect(decorationState[decoration2.id].top).toBe lineHeight * marker2.getScreenRange().start.row + 3 + 5
@@ -3286,8 +3285,6 @@ describe "TextEditorPresenter", ->
             presenter = buildPresenter(scrollTop: 0, lineHeight: 10)
             expect(presenter.getState().verticalScrollbar.scrollHeight).toBe editor.getScreenLineCount() * 10
 
-            # Setting `null` as the DOM element, as it doesn't really matter here.
-            # Maybe a signal that we should separate models from views?
             blockDecoration1 = editor.addBlockDecorationForScreenRow(0, null)
             blockDecoration2 = editor.addBlockDecorationForScreenRow(3, null)
             blockDecoration3 = editor.addBlockDecorationForScreenRow(7, null)
diff --git a/src/block-decorations-presenter.js b/src/block-decorations-presenter.js
index bfe08dd63..7f7258226 100644
--- a/src/block-decorations-presenter.js
+++ b/src/block-decorations-presenter.js
@@ -31,9 +31,6 @@ class BlockDecorationsPresenter {
   }
 
   observeModel () {
-    this.lineTopIndex.setMaxRow(this.model.getScreenLineCount())
-    this.lineTopIndex.setDefaultLineHeight(this.model.getLineHeightInPixels())
-
     this.disposables.add(this.model.onDidAddDecoration(this.observeDecoration.bind(this)))
     this.disposables.add(this.model.onDidChange((changeEvent) => {
       let oldExtent = changeEvent.end - changeEvent.start
@@ -54,11 +51,10 @@ class BlockDecorationsPresenter {
   setDimensionsForDecoration (decoration, width, height) {
     let block = this.blocksByDecoration.get(decoration)
     if (block) {
-      this.lineTopIndex.resizeBlock(block, height)
+      this.lineTopIndex.resizeBlock(decoration.getMarker().id, height)
     } else {
       this.observeDecoration(decoration)
-      block = this.blocksByDecoration.get(decoration)
-      this.lineTopIndex.resizeBlock(block, height)
+      this.lineTopIndex.resizeBlock(decoration.getMarker().id, height)
     }
 
     this.measuredDecorations.add(decoration)
@@ -124,9 +120,9 @@ class BlockDecorationsPresenter {
 
   didAddDecoration (decoration) {
     let screenRow = decoration.getMarker().getHeadScreenPosition().row
-    let block = this.lineTopIndex.insertBlock(screenRow, 0)
-    this.decorationsByBlock.set(block, decoration)
-    this.blocksByDecoration.set(decoration, block)
+    this.lineTopIndex.insertBlock(decoration.getMarker().id, screenRow, 0)
+    this.decorationsByBlock.set(decoration.getMarker().id, decoration)
+    this.blocksByDecoration.set(decoration, decoration.getMarker().id)
     this.emitter.emit('did-update-state')
   }
 
@@ -136,16 +132,15 @@ class BlockDecorationsPresenter {
       return
     }
 
-    let block = this.blocksByDecoration.get(decoration)
     let newScreenRow = decoration.getMarker().getHeadScreenPosition().row
-    this.lineTopIndex.moveBlock(block, newScreenRow)
+    this.lineTopIndex.moveBlock(decoration.getMarker().id, newScreenRow)
     this.emitter.emit('did-update-state')
   }
 
   didDestroyDecoration (decoration) {
     let block = this.blocksByDecoration.get(decoration)
     if (block) {
-      this.lineTopIndex.removeBlock(block)
+      this.lineTopIndex.removeBlock(decoration.getMarker().id)
       this.blocksByDecoration.delete(decoration)
       this.decorationsByBlock.delete(block)
     }
diff --git a/src/linear-line-top-index.js b/src/linear-line-top-index.js
index 3fe501ec9..aad947dd8 100644
--- a/src/linear-line-top-index.js
+++ b/src/linear-line-top-index.js
@@ -1,27 +1,23 @@
-'use strict'
+"use babel"
 
-module.exports =
-class LineTopIndex {
-  constructor () {
-    this.idCounter = 1
+export default class LineTopIndex {
+  constructor (params = {}) {
     this.blocks = []
-    this.maxRow = 0
-    this.defaultLineHeight = 0
+    this.maxRow = params.maxRow || 0
+    this.setDefaultLineHeight(params.defaultLineHeight || 0)
   }
 
   setDefaultLineHeight (lineHeight) {
     this.defaultLineHeight = lineHeight
   }
 
-  setMaxRow (maxRow) {
-    this.maxRow = maxRow
+  getMaxRow () {
+    return this.maxRow
   }
 
-  insertBlock (row, height) {
-    let id = this.idCounter++
+  insertBlock (id, row, height) {
     this.blocks.push({id, row, height})
     this.blocks.sort((a, b) => a.row - b.row)
-    return id
   }
 
   resizeBlock (id, height) {
@@ -62,26 +58,21 @@ class LineTopIndex {
           block.row += newExtent - oldExtent
         } else {
           block.row = startRow + newExtent
-          // invalidate marker?
         }
       }
     })
 
-    this.setMaxRow(this.maxRow + newExtent - oldExtent)
+    this.maxRow = this.maxRow + newExtent - oldExtent
   }
 
-  topPixelPositionForRow (row) {
+  pixelPositionForRow (row) {
     row = Math.min(row, this.maxRow)
     let linesHeight = row * this.defaultLineHeight
-    let blocksHeight = this.blocks.filter((block) => block.row < row).reduce((a, b) => a + b.height, 0)
+    let blocksHeight = this.blocks.filter((block) => block.row <= row).reduce((a, b) => a + b.height, 0)
     return linesHeight + blocksHeight
   }
 
-  bottomPixelPositionForRow (row) {
-    return this.topPixelPositionForRow(row + 1) - this.defaultLineHeight
-  }
-
-  rowForTopPixelPosition (top, strategy) {
+  rowForPixelPosition (top, strategy) {
     const roundingStrategy = strategy || 'floor'
     let blocksHeight = 0
     let lastRow = 0
diff --git a/src/lines-yardstick.coffee b/src/lines-yardstick.coffee
index 847ebfd46..e6454989a 100644
--- a/src/lines-yardstick.coffee
+++ b/src/lines-yardstick.coffee
@@ -22,7 +22,7 @@ class LinesYardstick
     targetTop = pixelPosition.top
     targetLeft = pixelPosition.left
     defaultCharWidth = @model.getDefaultCharWidth()
-    row = @lineTopIndex.rowForTopPixelPosition(targetTop, 'floor')
+    row = @lineTopIndex.rowForPixelPosition(targetTop, 'floor')
     targetLeft = 0 if targetTop < 0
     targetLeft = Infinity if row > @model.getLastScreenRow()
     row = Math.min(row, @model.getLastScreenRow())
@@ -91,7 +91,7 @@ class LinesYardstick
 
     @prepareScreenRowsForMeasurement([targetRow]) unless measureVisibleLinesOnly
 
-    top = @lineTopIndex.bottomPixelPositionForRow(targetRow)
+    top = @lineTopIndex.pixelPositionForRow(targetRow)
     left = @leftPixelPositionForScreenPosition(targetRow, targetColumn)
 
     @clearScreenRowsForMeasurement() unless measureVisibleLinesOnly
@@ -174,14 +174,14 @@ class LinesYardstick
     left + width - offset
 
   pixelRectForScreenRange: (screenRange, measureVisibleLinesOnly) ->
+    top = @lineTopIndex.pixelPositionForRow(screenRange.start.row)
     if screenRange.end.row > screenRange.start.row
-      top = @pixelPositionForScreenPosition(screenRange.start, true, measureVisibleLinesOnly).top
       left = 0
-      height = @lineTopIndex.topPixelPositionForRow(screenRange.end.row + 1) - top
+      height = @lineTopIndex.pixelPositionForRow(screenRange.end.row) - top + @model.getLineHeightInPixels()
       width = @presenter.getScrollWidth()
     else
-      {top, left} = @pixelPositionForScreenPosition(screenRange.start, false, measureVisibleLinesOnly)
-      height = @lineTopIndex.topPixelPositionForRow(screenRange.end.row + 1) - top
+      {left} = @pixelPositionForScreenPosition(screenRange.start, false, measureVisibleLinesOnly)
+      height = @lineTopIndex.pixelPositionForRow(screenRange.end.row) - top + @model.getLineHeightInPixels()
       width = @pixelPositionForScreenPosition(screenRange.end, false, measureVisibleLinesOnly).left - left
 
     {top, left, width, height}
diff --git a/src/text-editor-component.coffee b/src/text-editor-component.coffee
index c35139d7c..3e644a084 100644
--- a/src/text-editor-component.coffee
+++ b/src/text-editor-component.coffee
@@ -50,7 +50,10 @@ class TextEditorComponent
     @observeConfig()
     @setScrollSensitivity(@config.get('editor.scrollSensitivity'))
 
-    lineTopIndex = new LineTopIndex(@editor)
+    lineTopIndex = new LineTopIndex({
+      maxRow: @editor.getScreenLineCount(),
+      defaultLineHeight: @editor.getLineHeightInPixels()
+    })
     @presenter = new TextEditorPresenter
       model: @editor
       tileSize: tileSize
diff --git a/src/text-editor-presenter.coffee b/src/text-editor-presenter.coffee
index 5b1f01b35..ca05ea36a 100644
--- a/src/text-editor-presenter.coffee
+++ b/src/text-editor-presenter.coffee
@@ -442,8 +442,8 @@ class TextEditorPresenter
 
       continue if rowsWithinTile.length is 0
 
-      top = Math.round(@lineTopIndex.topPixelPositionForRow(tileStartRow))
-      bottom = Math.round(@lineTopIndex.topPixelPositionForRow(tileEndRow))
+      top = Math.round(@lineTopIndex.pixelPositionForRow(tileStartRow - 1) + @lineHeight)
+      bottom = Math.round(@lineTopIndex.pixelPositionForRow(tileEndRow - 1) + @lineHeight)
       height = bottom - top
 
       tile = @state.content.tiles[tileStartRow] ?= {}
@@ -659,8 +659,8 @@ class TextEditorPresenter
 
       continue unless @gutterIsVisible(gutter)
       for decorationId, {properties, screenRange} of @customGutterDecorationsByGutterName[gutterName]
-        top = @lineTopIndex.topPixelPositionForRow(screenRange.start.row)
-        bottom = @lineTopIndex.topPixelPositionForRow(screenRange.end.row + 1)
+        top = @lineTopIndex.pixelPositionForRow(screenRange.start.row)
+        bottom = @lineTopIndex.pixelPositionForRow(screenRange.end.row) + @lineHeight
         @customGutterDecorations[gutterName][decorationId] =
           top: top
           height: bottom - top
@@ -724,12 +724,12 @@ class TextEditorPresenter
   updateStartRow: ->
     return unless @scrollTop? and @lineHeight?
 
-    @startRow = Math.max(0, @lineTopIndex.rowForTopPixelPosition(@scrollTop, "floor"))
+    @startRow = Math.max(0, @lineTopIndex.rowForPixelPosition(@scrollTop, "floor"))
 
   updateEndRow: ->
     return unless @scrollTop? and @lineHeight? and @height?
 
-    @endRow = @lineTopIndex.rowForTopPixelPosition(@scrollTop + @height + @lineHeight, 'ceil')
+    @endRow = @lineTopIndex.rowForPixelPosition(@scrollTop + @height + @lineHeight, 'ceil')
 
   updateRowsPerPage: ->
     rowsPerPage = Math.floor(@getClientHeight() / @lineHeight)
@@ -761,7 +761,7 @@ class TextEditorPresenter
   updateVerticalDimensions: ->
     if @lineHeight?
       oldContentHeight = @contentHeight
-      @contentHeight = Math.round(@lineTopIndex.topPixelPositionForRow(Infinity))
+      @contentHeight = Math.round(@lineTopIndex.pixelPositionForRow(Infinity))
 
     if @contentHeight isnt oldContentHeight
       @updateHeight()
@@ -1340,7 +1340,7 @@ class TextEditorPresenter
       screenRange.end.column = 0
 
   repositionRegionWithinTile: (region, tileStartRow) ->
-    region.top  += @scrollTop - @lineTopIndex.topPixelPositionForRow(tileStartRow)
+    region.top  += @scrollTop - (@lineTopIndex.pixelPositionForRow(tileStartRow - 1) + @lineHeight)
     region.left += @scrollLeft
 
   buildHighlightRegions: (screenRange) ->
@@ -1495,7 +1495,7 @@ class TextEditorPresenter
     @emitDidUpdateState()
 
   didChangeFirstVisibleScreenRow: (screenRow) ->
-    @updateScrollTop(@lineTopIndex.topPixelPositionForRow(screenRow))
+    @updateScrollTop(@lineTopIndex.pixelPositionForRow(screenRow))
 
   getVerticalScrollMarginInPixels: ->
     Math.round(@model.getVerticalScrollMargin() * @lineHeight)
@@ -1516,8 +1516,8 @@ class TextEditorPresenter
 
     verticalScrollMarginInPixels = @getVerticalScrollMarginInPixels()
 
-    top = @lineTopIndex.bottomPixelPositionForRow(screenRange.start.row)
-    bottom = @lineTopIndex.bottomPixelPositionForRow(screenRange.end.row + 1)
+    top = @lineTopIndex.pixelPositionForRow(screenRange.start.row)
+    bottom = @lineTopIndex.pixelPositionForRow(screenRange.end.row) + @lineHeight
 
     if options?.center
       desiredScrollCenter = (top + bottom) / 2
@@ -1589,7 +1589,7 @@ class TextEditorPresenter
 
   restoreScrollTopIfNeeded: ->
     unless @scrollTop?
-      @updateScrollTop(@lineTopIndex.topPixelPositionForRow(@model.getFirstVisibleScreenRow()))
+      @updateScrollTop(@lineTopIndex.pixelPositionForRow(@model.getFirstVisibleScreenRow()))
 
   restoreScrollLeftIfNeeded: ->
     unless @scrollLeft?