Normal quotes

57-01.md

@@ -11,38 +11,38 @@ Chapter 57\
 I recently spent an hour or so learning how to shear a sheep. Among
 other things, I learned—in great detail—about the importance of
 selecting the proper comb for your shears, heard about the man who holds
-the world’s record for sheep sheared in a day (more than 600, if memory
+the world's record for sheep sheared in a day (more than 600, if memory
 serves), and discovered, Lord help me, the many and varied ways in which
 the New Zealand Sheep Shearing Board improves the approved
 sheep-shearing method every year. The fellow giving the presentation did
-his best, but let’s face it, sheep just aren’t very interesting. If you
-have children, you’ll know why I was there; if you don’t, there’s no use
+his best, but let's face it, sheep just aren't very interesting. If you
+have children, you'll know why I was there; if you don't, there's no use
 explaining.
 
 The chap doing the shearing did say one thing that stuck with me,
 although it may not sound particularly profound. (Actually, it sounds
-pretty silly, but bear with me.) He said, “You don’t get really good at
-sheep shearing for 10 years, or 10,000 sheep.” I’ll buy that. In fact,
+pretty silly, but bear with me.) He said, "You don't get really good at
+sheep shearing for 10 years, or 10,000 sheep." I'll buy that. In fact,
 to extend that morsel of wisdom to the greater, non-ovine-centric
 universe, it actually takes a good chunk of experience before you get
 good at anything worthwhile—especially graphics, for a couple of
 reasons. First, performance matters a lot in graphics, and performance
-programming is largely a matter of experience. You can’t speed up PC
+programming is largely a matter of experience. You can't speed up PC
 graphics simply by looking in a book for a better algorithm; you have to
 understand the code C compilers generate, assembly language
 optimization, VGA hardware, and the performance implications of various
 graphics-programming approaches and algorithms. Second, computer
 graphics is a matter of illusion, of convincing the eye to see what you
-want it to see, and that’s very much a black art based on experience.
+want it to see, and that's very much a black art based on experience.
 
 #### Visual Quality: A Black Hole ... Er, Art {#Heading3}
 
 Pleasing the eye with realtime computer animation is something less than
-a science, at least at the PC level, where there’s a limited color
+a science, at least at the PC level, where there's a limited color
 palette and no time for antialiasing; in fact, sometimes it can be more
 than a little frustrating. As you may recall, in the previous chapter I
 implemented texture mapping in X-Sharp. There was plenty of experience
-involved there, some of which I didn’t mention. My first implementation
+involved there, some of which I didn't mention. My first implementation
 was disappointing; the texture maps shimmied and sheared badly, like a
 loosely affiliated flock of pixels, each marching to its own drummer.
 Then, I added a control key to speed up the rotation; what a difference!
@@ -53,25 +53,25 @@ threshold into being accepted by the eye as a viewed object, rather than
 simply a collection of pixels.
 
 The obvious lesson here is that adequate speed is important to
-convincing animation. There’s another, less obvious side to this lesson,
-though. I’d been running the texture-mapping demo on a 20 MHz 386 with a
+convincing animation. There's another, less obvious side to this lesson,
+though. I'd been running the texture-mapping demo on a 20 MHz 386 with a
 slow VGA when I discovered the beneficial effects of greater animation
 speed. When, some time later, I ran the demo on a 33 MHz 486 with a fast
 VGA, I found that the faster rotation was too fast! The ball spun so
-rapidly that the eye couldn’t blend successive images together into
+rapidly that the eye couldn't blend successive images together into
 continuous motion, much like watching a badly flickering movie.
 
   ------------------- --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
-  ![](images/i.jpg)   *So the second lesson is that either too little or too much speed can destroy the illusion. Unless you’re antialiasing, you need to tune the shifting of your images so that they’re in the “sweet spot” of apparent motion, in which the eye is willing to ignore the jumping and aliasing, and blend the images together into continuous motion. Only experience can give you a feel for that sweet spot.*
+  ![](images/i.jpg)   *So the second lesson is that either too little or too much speed can destroy the illusion. Unless you're antialiasing, you need to tune the shifting of your images so that they're in the "sweet spot" of apparent motion, in which the eye is willing to ignore the jumping and aliasing, and blend the images together into continuous motion. Only experience can give you a feel for that sweet spot.*
   ------------------- --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 
 #### Fixed-Point Arithmetic, Redux {#Heading4}
 
 In the previous chapter I added texture mapping to X-Sharp, but lacked
-space to explain some of its finer points. I’ll pick up the thread now
+space to explain some of its finer points. I'll pick up the thread now
 and cover some of those points here, and discuss the visual and
-performance enhancements that previous chapter’s code needed—and which
-are now present in the version of X-Sharp in this chapter’s subdirectory
+performance enhancements that previous chapter's code needed—and which
+are now present in the version of X-Sharp in this chapter's subdirectory
 on the CD-ROM.
 
 Back in Chapter 38, I spent a good bit of time explaining exactly which
@@ -87,7 +87,7 @@ for speed and ease of use, would be unacceptable because round-off error
 would result in imprecise pixel placement.
 
 More than a year then passed between the time I wrote that statement and
-the time I implemented X-Sharp’s texture mapper, during which time my
+the time I implemented X-Sharp's texture mapper, during which time my
 long-term memory apparently suffered at least partial failure. When I
 went to implement texture mapping for the previous chapter, I decided
 that since transformed destination vertices can fall at fractional pixel
@@ -99,8 +99,8 @@ one small problem: gaps between polygons.
 
 Yes, folks, I had ignored the voice of experience (my own voice, at
 that) at my own peril. You can be assured I will not forget this
-particular lesson again: Fixed-point arithmetic is not precise. That’s
-not to say that it’s impossible to use fixed-point for drawing polygons;
+particular lesson again: Fixed-point arithmetic is not precise. That's
+not to say that it's impossible to use fixed-point for drawing polygons;
 if all adjacent edges share common start and end vertices and common
 edges are always stepped in the same direction, all polygons should
 share the same fixed-point imprecision, and edges should fit properly
@@ -120,7 +120,7 @@ appear to have shifted by one pixel at the corresponding destination
 pixel; given all the aliasing and shearing already going on in the
 texture-mapping process, a one-pixel mapping error is insignificant.
 
-Experience again: It’s the difference between knowing which flaws (like
+Experience again: It's the difference between knowing which flaws (like
 small texture shifts) can reasonably be ignored, and which (like those
 that produce gaps between polygons) must be avoided at all costs.