Merge pull request #433 from RayTracing/stb-comments

STB comments

Author: hollasch

books/RayTracingInOneWeekend.html

@@ -171,7 +171,8 @@
 If it doesn’t, then you probably just have some newlines or something similar that is confusing the
 image reader.
 
-If you want to produce more image types than PPM, I am a fan of `stb_image.h` available on github.
+If you want to produce more image types than PPM, I am a fan of `stb_image.h`, a header-only image
+library available on GitHub at https://github.com/nothings/stb.
 
 
 Adding a Progress Indicator

books/RayTracingTheNextWeek.html

@@ -1735,11 +1735,12 @@
 Storing Texture Image Data
 ---------------------------
 Now we also need to create a texture class that holds an image. I am going to use my favorite image
-utility `stb_image`. It reads in an image into a big array of unsigned char. These are just packed
-RGBs that each range 0..255 for black to fully-on.
+utility [stb_image][]. It reads in an image into a big array of unsigned char. These are just
+packed RGBs that each range 0..255 (black to full white). The `image_texture` class uses the
+resulting image data.
 
     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ C++
-    #include "texture.h"
+    #include "rtweekend.h"
 
     class image_texture : public texture {
         public:
@@ -1776,11 +1777,12 @@
             int nx, ny;
     };
     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-    [Listing [img-texture]: <kbd>[surface_texture.h]</kbd> Image texture class]
+    [Listing [img-texture]: <kbd>[texture.h]</kbd> Image texture class]
 
 <div class='together'>
-The representation of a packed array in that order is pretty standard. Thankfully, the `stb_image`
-package makes that super simple -- just include the header `rtw_stb_image.h` in `main.h`:
+The representation of a packed array in that order is pretty standard. Thankfully, the
+[stb_image][] package makes that super simple -- just include the header `rtw_stb_image.h` (found in
+the project source code at `src/common/rtw_stb_image.h`) in `main.h`:
 
     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ C++
     #include "rtw_stb_image.h"
@@ -2966,8 +2968,9 @@
 
 
 [acknowledgments]: #acknowledgments
-[Limnu]: https://limnu.com/
-[Markdeep]: https://casual-effects/markdeep/
+[Limnu]:           https://limnu.com/
+[Markdeep]:        https://casual-effects/markdeep/
+[stb_image]:       https://github.com/nothings/stb
 
 
 <!-- Markdeep: https://casual-effects.com/markdeep/ -->