diff options
| -rw-r--r-- | build.zig | 7 | ||||
| -rw-r--r-- | exercises/093_hello_c.zig | 2 | ||||
| -rw-r--r-- | exercises/094_c_math.zig | 33 | ||||
| -rw-r--r-- | patches/patches/094_c_math.patch | 4 |
4 files changed, 44 insertions, 2 deletions
@@ -471,7 +471,12 @@ const exercises = [_]Exercise{ }, .{ .main_file = "093_hello_c.zig", - .output = "Hello C from Zig! - C result ist 17 chars", + .output = "Hello C from Zig! - C result ist 17 chars written.", + .C = true, + }, + .{ + .main_file = "094_c_math.zig", + .output = "The normalized angle of 765.2 degrees is 45.2 degrees.", .C = true, }, .{ diff --git a/exercises/093_hello_c.zig b/exercises/093_hello_c.zig index b294f38..368a918 100644 --- a/exercises/093_hello_c.zig +++ b/exercises/093_hello_c.zig @@ -57,7 +57,7 @@ pub fn main() void { const c_res = write(2, "Hello C from Zig!", 17); // let's see what the result from C is: - std.debug.print(" - C result ist {d} chars\n", .{c_res}); + std.debug.print(" - C result ist {d} chars written.\n", .{c_res}); } // // Something must be considered when compiling with C functions. diff --git a/exercises/094_c_math.zig b/exercises/094_c_math.zig new file mode 100644 index 0000000..a8596b7 --- /dev/null +++ b/exercises/094_c_math.zig @@ -0,0 +1,33 @@ +// +// Often C functions are used where no equivalent Zig function exists +// yet. Since the integration of a C function is very simple as already +// seen in the last exercise, it naturally offers itself to use the +// very large variety of C functions for the own programs. +// In addition immediately an example: +// +// Let's say we have a given angle of 765.2 degrees. If we want to +// normalize that, it means that we have to subtract X * 360 degrees +// to get the correct angle. How could we do that? A good method is +// to use the modulo function. But if we write "765.2 % 360", it won't +// work, because the standard modulo function works only with integer +// values. In the C library "math" there is a function called "fmod". +// The "f" stands for floating and means that we can solve modulo for +// real numbers. With this function it should be possible to normalize +// our angel. Let's go. + +const std = @import("std"); + +const c = @cImport({ + // What do wee need here? + ??? +}); + +pub fn main() !void { + const angel = 765.2; + const circle = 360; + + // Here we call the C function 'fmod' to get our normalized angel. + const result = c.fmod(angel, circle); + + std.debug.print("The normalized angle of {d: >3.1} degrees is {d: >3.1} degrees.\n", .{ angel, result }); +} diff --git a/patches/patches/094_c_math.patch b/patches/patches/094_c_math.patch new file mode 100644 index 0000000..4b7d474 --- /dev/null +++ b/patches/patches/094_c_math.patch @@ -0,0 +1,4 @@ +22c22 +< ??? +--- +> @cInclude("math.h"); |