Normal quotes

42-01.md

@@ -3,24 +3,24 @@
   ------------------------ --------------------------------- --------------------
 
 Chapter 42\
- Wu’ed in Haste; Fried, Stewed at Leisure {#Heading1}
+ Wu'ed in Haste; Fried, Stewed at Leisure {#Heading1}
 -----------------------------------------
 
-### Fast Antialiased Lines Using Wu’s Algorithm {#Heading2}
+### Fast Antialiased Lines Using Wu's Algorithm {#Heading2}
 
 The thought first popped into my head as I unenthusiastically picked
-through the salad bar at a local “family” restaurant, trying to decide
+through the salad bar at a local "family" restaurant, trying to decide
 whether the meatballs, the fried clams, or the lasagna was likely to
 shorten my life the least. I decided on the chicken in mystery sauce.
 
-The thought recurred when my daughter asked, “Dad, is that fried
-chicken?”
+The thought recurred when my daughter asked, "Dad, is that fried
+chicken?"
 
-“I don’t think so,” I said. “I think it’s stewed chicken.”
+"I don't think so," I said. "I think it's stewed chicken."
 
-“It looks like fried chicken.”
+"It looks like fried chicken."
 
-“Maybe it’s fried, stewed chicken,” my wife volunteered hopefully. I
+"Maybe it's fried, stewed chicken," my wife volunteered hopefully. I
 took a bite. It was, indeed, fried, stewed chicken. I can now,
 unhesitatingly and without reservation, recommend that you avoid fried,
 stewed chicken at all costs.
@@ -32,15 +32,15 @@ Schumacher, is *appropriate technology*. For a family on a budget, with
 a small child, tired of staring at each other over the kitchen table,
 this was a perfect place to eat. It was cheap, it had greasy food and
 ice cream, no one cared if children dropped things or talked loudly or
-walked around, and, most important of all, it wasn’t home. So what if
+walked around, and, most important of all, it wasn't home. So what if
 the food was lousy? Good food was a luxury, a bonus; everything on the
 above list was necessary. A family restaurant was the appropriate
 dining-out technology, given the parameters within which we had to work.
 
 When I read through SIGGRAPH proceedings and other state-of-the-art
-computer-graphics material, all too often I feel like I’m dining at a
+computer-graphics material, all too often I feel like I'm dining at a
 four-star restaurant with two-year-old triplets and an empty wallet.
-We’re talking incredibly inappropriate technology for PC graphics here.
+We're talking incredibly inappropriate technology for PC graphics here.
 Sure, I say to myself as I read about an antialiasing technique, that
 sounds wonderful—if I had 24-bpp color, and dedicated hardware to do the
 processing, and all day to wait to generate one image. Yes, I think,
@@ -50,31 +50,31 @@ Graphics* is riveting, but, alas, pretty much useless on PCs. When an
 x86 has to do all the work, speed becomes the overriding parameter,
 especially for real-time graphics.
 
-Literature that’s applicable to fast PC graphics is hard enough to find,
-but what we’d really like is above-average image quality combined with
-terrific speed, and there’s almost no literature of that sort around.
+Literature that's applicable to fast PC graphics is hard enough to find,
+but what we'd really like is above-average image quality combined with
+terrific speed, and there's almost no literature of that sort around.
 There is some, however, and you folks are right on top of it. For
 example, alert reader Michael Chaplin, of San Diego, wrote to suggest
 that I might enjoy the line-antialiasing algorithm presented in Xiaolin
-Wu’s article, “An Efficient Antialiasing Technique,” in the July 1991
+Wu's article, "An Efficient Antialiasing Technique," in the July 1991
 issue of *Computer Graphics*. Michael was dead-on right. This is a great
 algorithm, combining excellent antialiased line quality with speed
-that’s close to that of non-antialiased Bresenham’s line drawing. This
+that's close to that of non-antialiased Bresenham's line drawing. This
 is the sort of algorithm that makes you want to go out and write a
 wire-frame animation program, just so you can see how good those smooth
 lines look in motion. Wu antialiasing is a wonderful example of what can
 be accomplished on inexpensive, mass-market hardware with the proper
-programming perspective. In short, it’s a splendid example of
+programming perspective. In short, it's a splendid example of
 appropriate technology for PCs.
 
 ### Wu Antialiasing {#Heading3}
 
-Antialiasing, as we’ve been discussing for the past few chapters, is the
+Antialiasing, as we've been discussing for the past few chapters, is the
 process of smoothing lines and edges so that they appear less jagged.
 Antialiasing is partly an aesthetic issue, because it makes images more
-attractive. It’s also partly an accuracy issue, because it makes it
+attractive. It's also partly an accuracy issue, because it makes it
 possible to position and draw images with effectively more precision
-than the resolution of the display. Finally, it’s partly a flat-out
+than the resolution of the display. Finally, it's partly a flat-out
 necessity, to avoid the horrible, crawling, jagged edges of temporal
 aliasing when performing animation.
 
@@ -83,8 +83,8 @@ the algorithm steps one pixel unit at a time along the major (longer)
 axis of a line, it draws the two pixels bracketing the line along the
 minor axis at each point. Each of the two bracketing pixels is drawn
 with a weighted fraction of the full intensity of the drawing color,
-with the weighting for each pixel equal to one minus the pixel’s
-distance along the minor axis from the ideal line. Yes, it’s a mouthful,
+with the weighting for each pixel equal to one minus the pixel's
+distance along the minor axis from the ideal line. Yes, it's a mouthful,
 but Figure 42.1 illustrates the concept.
 
 The intensities of the two pixels that bracket the line are selected so
@@ -100,7 +100,7 @@ jagged collection of pixel pairs, but as a smooth line centered on the
 ideal line. Thus, by weighting the bracketing pixels properly at each
 step, we can readily produce what looks like a smooth line at precisely
 the right location, rather than the jagged pattern of line segments that
-non-antialiased line-drawing algorithms such as Bresenham’s (see
+non-antialiased line-drawing algorithms such as Bresenham's (see
 Chapters 35, 36, and 37) trace out.
 
 ![](images/42-01.jpg)\
@@ -114,7 +114,7 @@ calculations involve only a few shifts, XORs, and adds; for all
 practical purposes, tracing and weighting are rolled into one step—and a
 very fast step it is. How fast is it? On a 33-MHz 486 with a fast VGA, a
 good but not maxed-out assembly implementation of Wu antialiasing draws
-a more than respectable 5,000 150-pixel-long vectors per second. That’s
+a more than respectable 5,000 150-pixel-long vectors per second. That's
 especially impressive considering that about 1,500,000 actual pixels are
 drawn per second, meaning that Wu antialiasing is drawing at around 50
 percent of the maximum memory bandwidth—half the fastest theoretically