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Diffstat (limited to 'Help/guide/tutorial/index.rst')
| -rw-r--r-- | Help/guide/tutorial/index.rst | 42 |
1 files changed, 24 insertions, 18 deletions
diff --git a/Help/guide/tutorial/index.rst b/Help/guide/tutorial/index.rst index 2aaca77..6327c3d 100644 --- a/Help/guide/tutorial/index.rst +++ b/Help/guide/tutorial/index.rst @@ -450,27 +450,29 @@ this step. Adding a Custom Command and Generated File (Step 6) =================================================== -In this section, we will add a generated source file into the build process -of an application. For this example, we will create a table of precomputed -square roots as part of the build process, and then compile that -table into our application. +Suppose, for the purpose of this tutorial, we decide that we never want to use +the platform ``log`` and ``exp`` functions and instead would like to +generate a table of precomputed values to use in the ``mysqrt`` function. +In this section, we will create the table as part of the build process, +and then compile that table into our application. -To accomplish this, we first need a program that will generate the table. In -the MathFunctions subdirectory a new source file named ``MakeTable.cxx`` will -do just that. +First, let's remove the check for the ``log`` and ``exp`` functions in +MathFunctions/CMakeLists. Then remove the check for ``HAVE_LOG`` and +``HAVE_EXP`` from ``mysqrt.cxx``. At the same time, we can remove +:code:`#include <cmath>`. -.. literalinclude:: Step7/MathFunctions/MakeTable.cxx - :language: c++ +In the MathFunctions subdirectory, a new source file named ``MakeTable.cxx`` +has been provided to generate the table. -Note that the table is produced as valid C++ code and that the output filename -is passed in as an argument. +After reviewing the file, we can see that the table is produced as valid C++ +code and that the output filename is passed in as an argument. -The next step is to add the appropriate commands to MathFunctions' CMakeLists +The next step is to add the appropriate commands to MathFunctions CMakeLists file to build the MakeTable executable and then run it as part of the build process. A few commands are needed to accomplish this. -First, the executable for ``MakeTable`` is added as any other executable would -be added. +First, at the top of MathFunctions/CMakeLists, the executable for ``MakeTable`` +is added as any other executable would be added. .. literalinclude:: Step7/MathFunctions/CMakeLists.txt :language: cmake @@ -509,10 +511,14 @@ Now let's use the generated table. First, modify ``mysqrt.cxx`` to include :start-after: // a hack square root calculation using simple operations Run **cmake** or **cmake-gui** to configure the project and then build it -with your chosen build tool. When this project is built it will first build -the ``MakeTable`` executable. It will then run ``MakeTable`` to produce -``Table.h``. Finally, it will compile ``mysqrt.cxx`` which includes -``Table.h`` to produce the MathFunctions library. +with your chosen build tool. + +When this project is built it will first build the ``MakeTable`` executable. +It will then run ``MakeTable`` to produce ``Table.h``. Finally, it will +compile ``mysqrt.cxx`` which includes ``Table.h`` to produce the MathFunctions +library. + +Run the Tutorial executable and verify that it is using the table. Building an Installer (Step 7) ============================== |