display progress bar

in_one_weekend/src/main.zig

@@ -44,6 +44,26 @@ fn rayColor(ray: Ray, world: World) Color {
     return white.mul(1.0 - t).add(blue.mul(t));
 }
 
+fn setProgress(surface: *sdl.c.SDL_Surface, width: usize, height: usize, percent: f32) void {
+    if (percent == 1.0) {
+        return;
+    }
+    
+    const progressBarHeight = 3;
+    const progressWidth = @floatToInt(usize, @intToFloat(f32, width) * percent);
+    const progressColor = Color{ .x = 1.0 };
+
+    var j: usize = 0;
+    while (j < progressBarHeight) {
+        var i: usize = 0;
+        while (i < progressWidth) {
+            sdl.setSurfacePixel(surface, i, j, progressColor);
+            i += 1;
+        }
+        j += 1;
+    }
+}
+
 pub fn main() anyerror!void {
     if (sdl.c.SDL_Init(sdl.c.SDL_INIT_VIDEO) != 0) {
         std.log.err("Unable to initialize SDL: {}", .{sdl.c.SDL_GetError()});
@@ -90,10 +110,26 @@ pub fn main() anyerror!void {
         pixel.* = Color{};
     }
 
-    {
+    if (sdl.c.SDL_UpdateWindowSurface(window) != 0) {
-        _ = sdl.c.SDL_LockSurface(surface);
+        std.log.err("Error updating window surface: {}", .{sdl.c.SDL_GetError()});
+        return error.SDLUpdateWindowFailed;
+    }
 
+    var running = true;
     var k: usize = 0;
+    while (running) {
+        var event: sdl.c.SDL_Event = undefined;
+        while (sdl.c.SDL_PollEvent(&event) != 0) {
+            switch (event.@"type") {
+                sdl.c.SDL_QUIT => {
+                    running = false;
+                },
+                else => {},
+            }
+        }
+
+        // Render
+        {
             while (k < samplesPerPixel) {
                 _ = sdl.c.SDL_LockSurface(surface);
 
@@ -118,28 +154,17 @@ pub fn main() anyerror!void {
                     }
                     j += 1;
                 }
+
+                setProgress(surface, imageWidth, imageHeight, @intToFloat(f32, k + 1) / @intToFloat(f32, samplesPerPixel));
+
                 sdl.c.SDL_UnlockSurface(surface);
                 _ = sdl.c.SDL_UpdateWindowSurface(window);
                 k += 1;
             }
         }
 
-    if (sdl.c.SDL_UpdateWindowSurface(window) != 0) {
+        if (k >= samplesPerPixel) {
-        std.log.err("Error updating window surface: {}", .{sdl.c.SDL_GetError()});
-        return error.SDLUpdateWindowFailed;
-    }
-
-    var running = true;
-    while (running) {
-        var event: sdl.c.SDL_Event = undefined;
-        while (sdl.c.SDL_PollEvent(&event) != 0) {
-            switch (event.@"type") {
-                sdl.c.SDL_QUIT => {
-                    running = false;
-                },
-                else => {},
-            }
-        }
             sdl.c.SDL_Delay(1000 / fps);
         }
+    }
 }