Data update

Task/Bitmap/Zig/bitmap.zig

@@ -0,0 +1,96 @@
+const std = @import("std");
+
+pub const Rgb = struct {
+    r: u8,
+    g: u8,
+    b: u8,
+};
+
+pub const PixelOutOfBounds = error{PixelOutOfBounds};
+
+pub const Bitmap = struct {
+    width: usize,
+   height: usize,
+   pixels: []Rgb,
+
+   // The ! next to the return type communicates that the function may return an error
+   pub fn new(allocator: std.mem.Allocator, width: usize, height: usize) !Bitmap {
+       // In Zig libraries that allocate receive an allocator
+      // instead of choosing one themselves
+       var pixels = try allocator.alloc(Rgb, width * height);
+
+      for (0..width*height) | i | {
+          pixels[i] = Rgb { .r = 0, .g = 0, .b = 0 };
+      }
+
+       return Bitmap {
+          .width = width,
+         .height = height,
+         .pixels = pixels,
+      };
+   }
+
+   pub fn free(self: Bitmap, allocator: std.mem.Allocator) void {
+      allocator.free(self.pixels);
+   }
+
+   pub fn fill(self: *Bitmap, color: Rgb) void {
+       for (0..self.width*self.height) | i | {
+          self.pixels[i] = color;
+      }
+   }
+
+   pub fn get_pixel_unchecked(self: Bitmap, x: usize, y: usize) Rgb {
+       return self.pixels[self.height * y + x];
+   }
+
+   pub fn get_pixel(self: Bitmap, x: usize, y: usize) !Rgb {
+       if (self.width <= x or self.height <= y) {
+          return error.PixelOutOfBounds;
+      }
+
+      return self.get_pixel_unchecked(x, y);
+   }
+
+   pub fn set_pixel_unchecked(self: *Bitmap, x: usize, y: usize, color: Rgb) void {
+       self.pixels[self.height * y + x] = color;
+   }
+
+   pub fn set_pixel(self: *Bitmap, x: usize, y: usize, color: Rgb) !void {
+       if (self.width <= x or self.height <= y) {
+          return error.PixelOutOfBounds;
+      }
+
+      return self.set_pixel_unchecked(x, y, color);
+   }
+};
+
+test "putting a pixel gets the pixel" {
+    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
+   const allocator = gpa.allocator();
+
+   var bm = try Bitmap.new(allocator, 10, 10);
+   defer bm.free(allocator);
+
+   try bm.set_pixel(4, 4, Rgb {.r=255, .g=0, .b=0});
+
+   const pixel = try bm.get_pixel(4, 4);
+
+   try std.testing.expectEqual(255, pixel.r);
+}
+
+test "filling a pixel gets all the pixels" {
+    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
+   const allocator = gpa.allocator();
+
+   var bm = try Bitmap.new(allocator, 10, 10);
+   defer bm.free(allocator);
+
+   bm.fill(Rgb {.r=255, .g=0, .b=0});
+
+   for (0..10) | x | {
+       for (0..10) | y | {
+          try std.testing.expectEqual(255, bm.get_pixel_unchecked(x, y).r);
+      }
+   }
+}