Update changelog to 2020-03-22

This includes reorganization of the whole file. Added introductory text
for both v2.0.0 and v3.0.0.

Author: hollasch

CHANGELOG.md

@@ -1,102 +1,123 @@
-Change Log
+Change Log -- Ray Tracing in One Weekend
 ====================================================================================================
 
-// Current to 00d0ab0 2020-03-05
+----------------------------------------------------------------------------------------------------
+# v3.0.0 (in progress) / Current to b3f0bbc 2020-03-21
 
-v3.0.0 (in progress)
----------------------
-Common
-- New: CMake configuration & build
-- New: File constants.h with portable math constants. Fixes [#151][]
-- New: `src/common` directory for code shared across books
-- New: Common project-wide header: `src/common/rtweekend.h`
-- New: `vec3::write_color` - provides a robust output method for color data (#93)
-- Change: Diffuse PDF computation uses random point _on_ sphere, rather than _inside_
+With the migration to a web format accomplished in v2.0.0, we immediately began work on a new major
+release: v3.0.0. This release tackles the following key themes:
+
+  - Establishing a common build system for the three projects. We chose CMake for its broad support
+    for multiple platforms, as well as multiple build tools and IDEs. This change includes a
+    reorganization of the project source files, and unifying a lot of code across projects.
+
+  - A major upgrade of the project source code, addressing a number of large changes that we had
+    deferred for later.
+
+  - A number of larger changes to the book content, refining some approaches and ideas, and
+    addressing some areas in the text that needed improvement.
+
+Following this release, we expect to switch to a much more incremental approach, mostly with
+patch-level (fix) changes and some minor-level (addition) changes.
+
+### Common to All Project Source
 - Change: Default floating-point type changed from `float` to `double` (#150)
-- Change: Disable compile warnings for external `stb_image.h` on Windows
-- Change: Replace pi with portable version. Fixes [#207][]
-- Change: Replace MAXFLOAT with (portable) infinity (#195, #216)
-- Change: A _lot_ of code refactoring throughout
-- New: `degrees_to_radians()` utility function (#217)
-- Change: Lots more highlighting of changed code in books to aid reading
-- Change: Improved random number generator utilities
-- Change: Math typesetting fixes throughout the books (#13)
+- Change: Materials are now referenced with `std::shared_ptr` pointers
+- Change: Complete elimination of bare pointers and `new`/`delete`
+- Change: `hittable_list` uses `std::vector` plus `std::shared_ptr` pointers
 - Change: Header cleanup across the source code (#218, #220)
-- New: Added code listing captions, including source file name, for all books (#238)
-- New: Added captions to all figures (#238)
-- Change: Improved naming of auxilliary programs in _The Rest Of Your Life_ source
 - Change: Cleaned up standard C++ header use (#19)
+- Change: Improved random number generator utilities
+- Change: Replace MAXFLOAT with (portable) infinity (#195, #216)
+- Change: A _lot_ of code cleanup, refactoring, renaming (#192)
+- Change: Disable compile warnings for external `stb_image.h` on Windows
+- Change: Replace pi with portable version (#207)
 - Change: `ray_color()` function now has max depth passed in, rather than hard-coding it (#143)
-- Fix: Fixed various minor problems in the text
-- Change: Code in source and in book reformatted to a consistent 96-column line length (#219)
-- Change: Books now use Markdeep's chapter indirection syntax
-- Fix: Fixed bug in `noise_texture::value()`
-- New: Clarified text around the ideal Lambertian distribution (#155)
 - Change: Added `random_in_unit_sphere()`, `random_unit_vector()`, `random_in_hemisphere()` to
   vec3.h. Fixed places where we were using one but should have been using another. (#145)
 - Change: General rework of the `vec3` header (#153, #156, #215)
-- Change: Updated several output images to match code updates
-- Change: Books general styling improvements (#197)
-- Change: Lots of code cleanup (#192)
 - Change: Clarify sphere intersection code, plus slight perf improvement (#113)
-- Change: Reworked Lambertian reflection text (#155)
-- Change: Added proper handling of front vs back face intersection
-- Add: Added progress output for main programs (#139)
-- Deleted: Several unused source files from `src/TheRestOfYourLife`
 - Change: `ray::point_at_parameter()` renamed to `ray::at()`
 - Change: Moved `ffmin()`, `ffmax()` from `aabb.h` to `rtweekend.h`
-- Fix: Delete unused variable `p` in main()
 - Change: Move low-level utility functions to more appropriate headers
-- Add: `random_int()`, `random_double()`, and `vec3::random()` utility functions
 - Change: `squared_length()` renamed to `length_squared()`
-- Add: Added safety value when surface texture has null data
-- Add: Local copy of `markdeep.min.js` for offline reading
 - Change: Update `sphere::hit()` function.
-- Add: Additional explanatory text to the dielectric chapter
 - Change: Refraction variables renamed to match reflection variable names
-- Change: `hittable_list` uses `std::vector` plus `std::shared_ptr` pointers
-- Change: Materials are now referenced with `std::shared_ptr` pointers
-- Change: Complete elimination of bare pointers and `new`/`delete`
-- Change: Assorted variable renames for clarity
-- Add: "The Next Week" main program added swtich statement for different scenes
-- Add: "The Next Week" main program now defines all image/camera parameters for each scene
-- Add: Main programs now define and handle parameterized background color
-- Change: General refactorings of code for clarity / simplicity
-- Change: Refactored acknowledgements. These are now moved to and duplicated in each book
 - Change: Simplify lambertian scatter direction calculation
-- Change: Improve color [0,1] -> [0,255] mapping
-- Add: Draft image for hemispherical rendering
+- New: CMake configuration & build
+- New: Added progress output for main programs (#139)
+- New: `src/common` directory for code shared across books
+- New: Common project-wide header: `src/common/rtweekend.h`
+- New: File constants.h with portable math constants (#151)
+- New: `vec3::write_color` - provides a robust output method for color data (#93)
+- New: `degrees_to_radians()` utility function (#217)
+- New: `random_int()`, `random_double()`, and `vec3::random()` utility functions
+- New: Added safety value when surface texture has null data
+- New: Main programs now define and handle parameterized background color
+- Fix: Diffuse PDF computation uses random point _on_ sphere, rather than _inside_
+- Fix: Improve color [0,1] -> [0,255] mapping
+
+### Common to All Books
+- Change: Code in source and in book reformatted to a consistent 96-column line length (#219)
+- Change: Lots more highlighting of changed code in books to aid reading
+- Change: Math typesetting fixes throughout the books (#13)
+- Change: Books now use Markdeep's chapter indirection syntax
+- Change: Updated several output images to match code updates
+- Change: Books general styling improvements (#197)
+- Change: Refactored acknowledgements. These are now moved to and duplicated in each book
+- New: Added code listing captions, including source file name, for all books (#238)
+- New: Added captions to all figures (#238)
+- New: Local copy of `markdeep.min.js` for offline reading
+- Fix: Fixed various minor problems in the text
+
+### _In One Weekend_
+- Change: Reworked Lambertian reflection text (#155)
+- New: Clarified text around the ideal Lambertian distribution (#155)
+- New: Additional explanatory text to the dielectric chapter
+- New: Image for hemispherical rendering
+- Fix: Update `ray_color()` code blocks to match current source (#391)
+
+### _The Next Week_
+- Change: Added proper handling of front vs back face intersection (#270)
+- New: "The Next Week" main program added swtich statement for different scenes
+- New: "The Next Week" main program now defines all image/camera parameters for each scene
+- Fix: Fixed bug in `noise_texture::value()` (#396)
 - Fix: Correct first Perlin noise() function in "The Next Week".
+- Fix: Fix OCR error in `texture::value()` function (#399)
+- Fix: Remove premature declaration of `moving_sphere::bounding_box()` (#405)
 
+### _The Rest of Your Life_
+- Change: Improved naming of auxilliary programs in _The Rest of Your Life_ source
+- Fix: Delete unused variable `p` in main() (#317)
+- Deleted: Several unused source files from `src/TheRestOfYourLife`
+
+
+----------------------------------------------------------------------------------------------------
+# v2.0.0 (2019-10-07)
+
+This major release marks an overhaul of the entire series, moving from a primarily PDF format to a
+web accessible format using Markdeep (https://casual-effects.com/markdeep/). This represents a huge
+overhaul to the contents, particularly around source code blocks in the text, mathematical
+typesetting and source-code cleanup.
 
-v2.0.0 (2019-10-07)
---------------------
-Common
+### Common
+- Change: Moved existing _InOneWeekend_, _TheNextWeek_, _TheRestOfYourLife_ content to io repo
+- Change: Rewrote vec3.h `cross` function for clarity
 - New: General release to web
 - New: Created single monolithic raytracing.github.io repo
 - New: License change to CC0 in COPYING.txt
-- Delete: Deprecated existing _InOneWeekend_, _TheNextWeek_, _TheRestOfYourLife_ repos
-- Change: Moved existing _InOneWeekend_, _TheNextWeek_, _TheRestOfYourLife_ content to io repo
-- Add: CHANGELOG.md
-- Add: CONTRIBUTING.md
-- Add: COPYING.txt
-- Add: README.md
-- Add: raytracing.github.io links to all the three books
-- Add: CSS for all books
-- Add: CSS for the print variant of the books
+- New: CHANGELOG.md
+- New: CONTRIBUTING.md
+- New: COPYING.txt
+- New: README.md
+- New: raytracing.github.io links to all the three books
+- New: CSS for all books
+- New: CSS for the print variant of the books
 - Fix: All instances of `hitable` have become `hittable`
 - Fix: Replaced `drand48()` with portable `random_double` number generation
-- Change: Rewrote vec3.h `cross` function for clarity
-
+- Delete: Deprecated existing _InOneWeekend_, _TheNextWeek_, _TheRestOfYourLife_ repos
 
-_Ray Tracing in One Weekend_
-- Fix: Text, Chapter 7, Add `#include "random.h"` in code blocks
-- Fix: Text, Chapter 10, Added metal fuzziness parameter for initial dielectric
-- Fix: Text, Chapter 13, Added metal fuzziness parameter
-- Fix: Code, Removed extraneous `;` from `vec3::&operator[]` signature
-- New: Markdeep page created for entire body of text
-- New: Markdeep MathJax for formulae and equations for body of text
-- New: raytracing.github.io/books/RayTracingInOneWeekend.html
+### _In One Weekend_
 - Change: README files updated for top level, source, and books
 - Change: Text, Chapter 0 Overview has become Chapter 1, all subsequent chapters incremented
 - Change: Text, Syntax highlighting of source modifications
@@ -113,20 +134,16 @@ _Ray Tracing in One Weekend_
 - Change: Text, Chapter 10, Put function signatures and `{` on the same line
 - Change: Text, Chapter 11, Consistent use of spaces in code blocks
 - Change: Text, Chapter 13, Put function signatures and `{` on the same line
+- New: Markdeep page created for entire body of text
+- New: Markdeep MathJax for formulae and equations for body of text
+- New: raytracing.github.io/books/RayTracingInOneWeekend.html
+- Fix: Text, Chapter 7, Add `#include "random.h"` in code blocks
+- Fix: Text, Chapter 10, Added metal fuzziness parameter for initial dielectric
+- Fix: Text, Chapter 13, Added metal fuzziness parameter
+- Fix: Code, Removed extraneous `;` from `vec3::&operator[]` signature
 - Delete: Code, `vec3 p = r.point_at_parameter(2.0);` in main.cc
 
-
-_Ray Tracing: The Next Week_
-- Fix: Text, Chapter 2, The `lambertian` class definition now uses `vec3` instead of `texture`
-- Fix: Text, Chapter 7, Changed `cornell_box` hittable array size to 5
-- Fix: Code and Text, Chapter 3, Changed `List[0]` to `List[i]` in `hittable_list::bounding_box()`
-- Fix: Code and Text, Chapter 3, Replaced `fmax` and `fmin` with `ffmax` and `ffmin`
-- Fix: Code, Add missing headers to `constant_medium.h` to fix g++ compiler error
-- New: raytracing.github.io/books/RayTracingTheNextWeek.html
-- Add: README.md, source README.md
-- Add: Markdeep page created for entire body of text
-- Add: Markdeep MathJax created for formulae and equations for body of text
-- Add: Earth map picture for use in rendering
+### _The Next Week_
 - Change: Text, Chapter 0 Overview has become Chapter 1, all subsequent chapters incremented
 - Change: Text, Syntax highlighting of source modifications
 - Change: Text, Chapter 2, Consistent use of spaces in code blocks
@@ -141,18 +158,18 @@ _Ray Tracing: The Next Week_
 - Change: Text, Chapter 10, Consistent use of spaces in code blocks
 - Change: Code and Text, Chapter 9, cleaned up implementation of `constant_medium::hit`
 - Change: Code and Text, Chapter 9, Rewrote debug functionality in `constant_medium::hit`
+- New: raytracing.github.io/books/RayTracingTheNextWeek.html
+- New: README.md, source README.md
+- New: Markdeep page created for entire body of text
+- New: Markdeep MathJax created for formulae and equations for body of text
+- New: Earth map picture for use in rendering
+- Fix: Text, Chapter 2, The `lambertian` class definition now uses `vec3` instead of `texture`
+- Fix: Text, Chapter 7, Changed `cornell_box` hittable array size to 5
+- Fix: Code and Text, Chapter 3, Changed `List[0]` to `List[i]` in `hittable_list::bounding_box()`
+- Fix: Code and Text, Chapter 3, Replaced `fmax` and `fmin` with `ffmax` and `ffmin`
+- Fix: Code, Add missing headers to `constant_medium.h` to fix g++ compiler error
 
-
-_Ray Tracing: The Rest of Your Life_
-- Fix: Text, Chapter order starting from chapter 2
-- Fix: Text, Renamed figures and images to match new chapter numbering
-- Fix: Text, Chapter 4, Rewrote formula for "Color" to "Color = A * color(direction"
-- Fix: Code and Text, Chapter 6, `material::scattering_pdf` now returns type float
-- Fix: Code and Text, Chapter 6, removal of factor of 2 to `random_cosine_direction` calculation
-- New: raytracing.github.io/books/RayTracingTheRestOfYourLife.html
-- Add: README.md, source README.md
-- Add: Markdeep page created for entire body of text
-- Add: Markdeep MathJax created for formulae and equations for body of text
+### _The Rest of Your Life_
 - Change: Text, Chapter 0 Overview has become Chapter 1, all subsequent chapters incremented
 - Change: Text, Syntax highlighting of source modifications
 - Change: Text, Chapter 2, Reorder include files in code blocks to match src conventions
@@ -161,25 +178,31 @@ _Ray Tracing: The Rest of Your Life_
 - Change: Text, Chapter 6, Consistent use of spaces in code blocks
 - Change: Text, Chapter 8, Changed calculation of `a` axis to pseudocode
 - Change: Text, Chapter 8, Consistent use of spaces in code blocks
+- New: raytracing.github.io/books/RayTracingTheRestOfYourLife.html
+- New: README.md, source README.md
+- New: Markdeep page created for entire body of text
+- New: Markdeep MathJax created for formulae and equations for body of text
+- Fix: Text, Chapter order starting from chapter 2
+- Fix: Text, Renamed figures and images to match new chapter numbering
+- Fix: Text, Chapter 4, Rewrote formula for "Color" to "Color = A * color(direction"
+- Fix: Code and Text, Chapter 6, `material::scattering_pdf` now returns type float
+- Fix: Code and Text, Chapter 6, removal of factor of 2 to `random_cosine_direction` calculation
+
 
+----------------------------------------------------------------------------------------------------
+# v1.123.0  (2018-08-26)
 
-v1.123.0  (2018-08-26)
------------------------
-_Ray Tracing: The Rest of Your Life_
-- New: First GitHub release.
+- New: First GitHub release of _Ray Tracing: The Rest of Your Life_.
 
 
-v1.54.0  (2018-08-26)
-----------------------
-_Ray Tracing in One Weekend_
-- New: First GitHub release.
+----------------------------------------------------------------------------------------------------
+# v1.54.0  (2018-08-26)
 
+- New: First GitHub release of _Ray Tracing in One Weekend_.
 
-v1.42.0  (2018-08-26)
-----------------------
-_Ray Tracing: The Next Week_
-- New: First GitHub release.
 
+----------------------------------------------------------------------------------------------------
+# v1.42.0  (2018-08-26)
 
+- New: First GitHub release of _Ray Tracing: The Next Week_.
 
-[#195]: https://github.com/raytracing/raytracing.github.io/issues/#195