implement random walk for enemies

fixes carts running too slow in chrome

examples/curlywas/sprites.cwa

@@ -0,0 +1,21 @@
+include "../include/microw8-api.cwa"
+
+const SPRITE = 0x20000;
+
+export fn upd() {
+	cls(0);
+	let t = time();
+	let i: i32;
+	loop spriteLoop {
+		let inline x = sin(t * -1.3 + i as f32 / 8_f) * 180_f + 160_f;
+		let inline y = sin(t * 1.7 + i as f32 / 9_f) * 140_f + 120_f;
+		blitSprite(SPRITE, 16, x as i32, y as i32, 0x100);
+		branch_if (i +:= 1) < 200: spriteLoop;
+	}
+}
+
+start fn start() {
+	printChar('OO');
+	circle(8_f, 8_f, 6_f, 75);
+	grabSprite(SPRITE, 16, 0, 0, 0);
+}

examples/include/microw8-api.cwa

@@ -30,11 +30,13 @@ import "env.printInt" fn printInt(i32);
 import "env.setTextColor" fn setTextColor(i32);
 import "env.setBackgroundColor" fn setBackgroundColor(i32);
 import "env.setCursorPosition" fn setCursorPosition(i32, i32);
-import "env.rectangle_outline" fn rectangle_outline(f32, f32, f32, f32, i32);
-import "env.circle_outline" fn circle_outline(f32, f32, f32, i32);
+import "env.rectangleOutline" fn rectangleOutline(f32, f32, f32, f32, i32);
+import "env.circleOutline" fn circleOutline(f32, f32, f32, i32);
 import "env.exp" fn exp(f32) -> f32;
 import "env.playNote" fn playNote(i32, i32);
 import "env.sndGes" fn sndGes(i32) -> f32;
+import "env.blitSprite" fn blitSprite(i32, i32, i32, i32, i32);
+import "env.grabSprite" fn grabSprite(i32, i32, i32, i32, i32);
 
 const TIME_MS = 0x40;
 const GAMEPAD = 0x44;

examples/include/microw8-api.wat

@@ -30,11 +30,13 @@
 (import "env" "setTextColor" (func $setTextColor (param i32)))
 (import "env" "setBackgroundColor" (func $setBackgroundColor (param i32)))
 (import "env" "setCursorPosition" (func $setCursorPosition (param i32) (param i32)))
-(import "env" "rectangle_outline" (func $rectangle_outline (param f32) (param f32) (param f32) (param f32) (param i32)))
-(import "env" "circle_outline" (func $circle_outline (param f32) (param f32) (param f32) (param i32)))
+(import "env" "rectangleOutline" (func $rectangleOutline (param f32) (param f32) (param f32) (param f32) (param i32)))
+(import "env" "circleOutline" (func $circleOutline (param f32) (param f32) (param f32) (param i32)))
 (import "env" "exp" (func $exp (param f32) (result f32)))
 (import "env" "playNote" (func $playNote (param i32) (param i32)))
 (import "env" "sndGes" (func $sndGes (param i32) (result f32)))
+(import "env" "blitSprite" (func $blitSprite (param i32) (param i32) (param i32) (param i32) (param i32)))
+(import "env" "grabSprite" (func $grabSprite (param i32) (param i32) (param i32) (param i32) (param i32)))
 
 ;; to use defines, include this file with a preprocessor
 ;; like gpp (https://logological.org/gpp).

examples/zig/.gitignore

@@ -1,2 +1,2 @@
-/zig-cache/
-/zig-out/
+zig-cache/
+zig-out/

examples/zig/game/build.zig

@@ -5,11 +5,7 @@ pub fn build(b: *std.build.Builder) void {
 
     const lib = b.addSharedLibrary("cart", "main.zig", .unversioned);
     lib.setBuildMode(mode);
-    lib.setTarget(.{
-        .cpu_arch = .wasm32,
-        .os_tag = .freestanding,
-        .cpu_features_add = std.Target.wasm.featureSet(&.{ .nontrapping_fptoint })
-    });
+    lib.setTarget(.{ .cpu_arch = .wasm32, .os_tag = .freestanding, .cpu_features_add = std.Target.wasm.featureSet(&.{.nontrapping_fptoint}) });
     lib.import_memory = true;
     lib.initial_memory = 262144;
     lib.max_memory = 262144;
@@ -18,19 +14,13 @@ pub fn build(b: *std.build.Builder) void {
     lib.install();
 
     if (lib.install_step) |install_step| {
-        const run_filter_exports = b.addSystemCommand(&[_][]const u8{
-            "uw8", "filter-exports", "zig-out/lib/cart.wasm", "zig-out/lib/cart-filtered.wasm"
-        });
+        const run_filter_exports = b.addSystemCommand(&[_][]const u8{ "uw8", "filter-exports", "zig-out/lib/cart.wasm", "zig-out/lib/cart-filtered.wasm" });
         run_filter_exports.step.dependOn(&install_step.step);
 
-        const run_wasm_opt = b.addSystemCommand(&[_][]const u8{
-            "wasm-opt", "-Oz", "-o", "zig-out/cart.wasm", "zig-out/lib/cart-filtered.wasm"
-        });
+        const run_wasm_opt = b.addSystemCommand(&[_][]const u8{ "wasm-opt", "--enable-nontrapping-float-to-int", "-Oz", "-o", "zig-out/cart.wasm", "zig-out/lib/cart-filtered.wasm" });
         run_wasm_opt.step.dependOn(&run_filter_exports.step);
 
-        const run_uw8_pack = b.addSystemCommand(&[_][]const u8{
-            "uw8", "pack", "-l", "9", "zig-out/cart.wasm", "zig-out/cart.uw8"
-        });
+        const run_uw8_pack = b.addSystemCommand(&[_][]const u8{ "uw8", "pack", "-l", "5", "zig-out/cart.wasm", "zig-out/cart.uw8" });
         run_uw8_pack.step.dependOn(&run_wasm_opt.step);
 
         const make_opt = b.step("make_opt", "make size optimized cart");

examples/zig/game/main.zig

@@ -0,0 +1,142 @@
+const uw8 = @import("uw8.zig");
+
+var redBallSprite: [16 * 16]u8 = undefined;
+var greenBallSprite: [16 * 16]u8 = undefined;
+var blueBallSprite: [16 * 16]u8 = undefined;
+var wallSprite: [24 * 24]u8 = undefined;
+
+const SphereConfigStep = struct { size: u8, color: u8 };
+// zig fmt: off
+const redSphereConfig: [4]SphereConfigStep = .{
+    .{ .size = 0, .color = 0x3d },
+    .{ .size = 2, .color = 0x48 },
+    .{ .size = 6, .color = 0x65 },
+    .{ .size = 9, .color = 0x55 }
+};
+const greenSphereConfig: [4]SphereConfigStep = .{
+    .{ .size = 0, .color = 0x7d },
+    .{ .size = 2, .color = 0x88 },
+    .{ .size = 6, .color = 0x96 },
+    .{ .size = 9, .color = 0xa3 }
+};
+const blueSphereConfig: [4]SphereConfigStep = .{
+    .{ .size = 0, .color = 0x2e },
+    .{ .size = 2, .color = 0x19 },
+    .{ .size = 6, .color = 0x17 },
+    .{ .size = 9, .color = 0x24 }
+};
+
+const levelData: [14] *const [19]u8 = .{
+  "xxxxxxxxxxxxxxxxxxx",
+  "x      x   x      x",
+  "x x xx   x   xx x x",
+  "x x  xxx x xxx  x x",
+  "x xx x       x xx x",
+  "x xx   xxxxx   xx x",
+  "x    x       x    x",
+  "x xx xx xxx xx xx x",
+  "x  x xx     xx x  x",
+  "xx x    x x    x xx",
+  "x  xx xxx xxx xx  x",
+  "x xx   x   x   xx x",
+  "x    x   x   x    x",
+  "xxxxxxxxxxxxxxxxxxx",
+};
+// zig fmt: on
+
+export fn start() void {
+    blitSphere(&redBallSprite, &redSphereConfig);
+    blitSphere(&greenBallSprite, &greenSphereConfig);
+    blitSphere(&blueBallSprite, &blueSphereConfig);
+
+    createWallSprite();
+}
+
+fn blitSphere(sprite: [*]u8, config: []const SphereConfigStep) void {
+    for (config) |circle| {
+        uw8.circle(8, 8, 8, circle.color);
+        uw8.circle(5, 6, @intToFloat(f32, circle.size), 0);
+        uw8.grabSprite(sprite, 16, 0, 0, 0x100);
+    }
+}
+
+fn createWallSprite() void {
+    uw8.cls(0xe4);
+    var i: i32 = 0;
+    while (i < 50) : (i += 1) {
+        const x = uw8.randomf() * 16;
+        const y = uw8.randomf() * 16;
+        const radius = uw8.randomf() * 2 + 1;
+        const c = @intCast(u8, (uw8.random() & 3)) + 0x95;
+        var j: i32 = 0;
+        while (j < 9) : (j += 1) {
+            uw8.circle(x + @intToFloat(f32, @rem(j, 3) * 16), y + @intToFloat(f32, @divFloor(j, 3) * 16), radius, c);
+        }
+    }
+    uw8.grabSprite(&wallSprite, 16, 16, 16, 0);
+}
+
+export fn upd() void {
+    uw8.cls(0);
+
+    var y: usize = 0;
+    while (y < levelData.len) : (y += 1) {
+        var x: usize = 0;
+        while (x < levelData[y].len) : (x += 1) {
+            if (levelData[y][x] == 'x') {
+                uw8.blitSprite(&wallSprite, 16, 8 + @intCast(i32, x) * 16, @intCast(i32, y) * 16, 0);
+            }
+        }
+    }
+
+    updateEnemy(&enemies[0], &redBallSprite);
+    updateEnemy(&enemies[1], &greenBallSprite);
+    updateEnemy(&enemies[2], &blueBallSprite);
+}
+
+const EntityState = struct { x: i32, y: i32, dir: u2 };
+var enemies: [3]EntityState = .{
+    .{ .x = 16, .y = 16, .dir = 1 },
+    .{ .x = 16 * 18, .y = 16, .dir = 3 },
+    .{ .x = 16, .y = 16 * 12, .dir = 1 },
+};
+
+fn updateEnemy(enemy: *EntityState, sprite: [*]u8) void {
+    switch (enemy.dir) {
+        0 => enemy.y -= 1,
+        1 => enemy.x += 1,
+        2 => enemy.y += 1,
+        3 => enemy.x -= 1,
+    }
+    if (((enemy.x | enemy.y) & 15) == 0) {
+        const tx = @intCast(usize, enemy.x) / 16;
+        const ty = @intCast(usize, enemy.y) / 16;
+        var dir = enemy.dir;
+        var count: u32 = 0;
+        if (enemy.dir != 2 and levelData[ty - 1][tx] == ' ') {
+            dir = 0;
+            count += 1;
+        }
+        if (enemy.dir != 3 and levelData[ty][tx + 1] == ' ') {
+            count += 1;
+            if (uw8.random() % count == 0) {
+                dir = 1;
+            }
+        }
+        if (enemy.dir != 0 and levelData[ty + 1][tx] == ' ') {
+            count += 1;
+            if (uw8.random() % count == 0) {
+                dir = 2;
+            }
+        }
+        if (enemy.dir != 1 and levelData[ty][tx - 1] == ' ') {
+            count += 1;
+            if (uw8.random() % count == 0) {
+                dir = 3;
+            }
+        }
+        enemy.dir = dir;
+    }
+
+    uw8.blitSprite(sprite, 16, 8 + enemy.x, enemy.y, 0x100);
+}

examples/zig/game/uw8.zig

@@ -0,0 +1,10 @@
+pub extern fn random() u32;
+pub extern fn randomf() f32;
+pub extern fn time() f32;
+pub extern fn cls(color: u8) void;
+pub extern fn circle(x: f32, y: f32, radiu: f32, color: u8) void;
+pub extern fn blitSprite(spriteData: [*]u8, size: u32, x: i32, y: i32, ctrl: u32) void;
+pub extern fn grabSprite(spriteData: [*]u8, size: u32, x: i32, y: i32, ctrl: u32) void;
+pub extern fn printString(str: [*:0]u8) void;
+pub extern fn printInt(value: i32) void;
+pub extern fn printChar(char: u32) void;

examples/zig/tunnel/build.zig

@@ -0,0 +1,31 @@
+const std = @import("std");
+
+pub fn build(b: *std.build.Builder) void {
+    const mode = std.builtin.Mode.ReleaseSmall;
+
+    const lib = b.addSharedLibrary("cart", "main.zig", .unversioned);
+    lib.setBuildMode(mode);
+    lib.setTarget(.{ .cpu_arch = .wasm32, .os_tag = .freestanding, .cpu_features_add = std.Target.wasm.featureSet(&.{.nontrapping_fptoint}) });
+    lib.import_memory = true;
+    lib.initial_memory = 262144;
+    lib.max_memory = 262144;
+    lib.global_base = 81920;
+    lib.stack_size = 8192;
+    lib.install();
+
+    if (lib.install_step) |install_step| {
+        const run_filter_exports = b.addSystemCommand(&[_][]const u8{ "uw8", "filter-exports", "zig-out/lib/cart.wasm", "zig-out/lib/cart-filtered.wasm" });
+        run_filter_exports.step.dependOn(&install_step.step);
+
+        const run_wasm_opt = b.addSystemCommand(&[_][]const u8{ "wasm-opt", "--enable-nontrapping-float-to-int", "-Oz", "-o", "zig-out/cart.wasm", "zig-out/lib/cart-filtered.wasm" });
+        run_wasm_opt.step.dependOn(&run_filter_exports.step);
+
+        const run_uw8_pack = b.addSystemCommand(&[_][]const u8{ "uw8", "pack", "-l", "9", "zig-out/cart.wasm", "zig-out/cart.uw8" });
+        run_uw8_pack.step.dependOn(&run_wasm_opt.step);
+
+        const make_opt = b.step("make_opt", "make size optimized cart");
+        make_opt.dependOn(&run_uw8_pack.step);
+
+        b.default_step = make_opt;
+    }
+}

examples/zig/tunnel/main.zig

@@ -13,8 +13,10 @@ export fn upd() void {
         var u = atan2(x, y) * 512.0 / 3.141;
         var c = @intCast(u8, (@floatToInt(i32, d + t * 2.0) ^ @floatToInt(i32, u + t)) & 255) >> 4;
 
-        FRAMEBUFFER[@as(usize, i)] = c;
+        FRAMEBUFFER[i] = c;
         i += 1;
-        if(i >= 320*240) { break; }
+        if (i >= 320 * 240) {
+            break;
+        }
     }
 }

platform/src/platform.cwa

@@ -171,7 +171,7 @@ export fn rectangle(x: f32, y: f32, w: f32, h: f32, col: i32) {
     }
 }
 
-export fn rectangle_outline(x: f32, y: f32, w: f32, h: f32, col: i32) {
+export fn rectangleOutline(x: f32, y: f32, w: f32, h: f32, col: i32) {
     let xl = nearest(x) as i32;
     let xr = nearest(x + w) as i32;
     let yt = nearest(y) as i32;
@@ -212,7 +212,7 @@ export fn circle(cx: f32, cy: f32, radius: f32, col: i32) {
     }
 }
 
-export fn circle_outline(cx: f32, cy: f32, radius: f32, col: i32) {
+export fn circleOutline(cx: f32, cy: f32, radius: f32, col: i32) {
     let prev_w: f32;
     let y = clamp(nearest(cy - radius) as i32, -1, 241);
     let maxY = clamp(nearest(cy + radius) as i32, -1, 241);
@@ -352,6 +352,92 @@ export fn line(x1: f32, y1: f32, x2: f32, y2: f32, col: i32) {
     setPixel(i32.trunc_sat_f32_s(x1 + f * dx), i32.trunc_sat_f32_s(y1 + f * dy), col);
 }
 
+export fn blitSprite(sprite: i32, size: i32, x: i32, y: i32, control: i32) {
+    let lazy width = size & 65535;
+    let lazy height = select(size >> 16, size >> 16, width);
+
+    let lazy x0 = select(x < 0, -x, 0);
+    let lazy x1 = select(x + width > 320, 320 - x, width);
+    let lazy y0 = select(y < 0, -y, 0);
+    let lazy y1 = select(y + height > 240, 240 - y, height);
+
+    let lazy numRows = y1 - y0;
+    let lazy numCols = x1 - x0;
+    if numRows <= 0 | numCols <= 0 {
+        return;
+    }
+
+    let trans = (control & 511) - 256;
+    let lazy flip_x = 1 - ((control >> 8) & 2);
+    let lazy flip_y = 1 - ((control >> 9) & 2);
+    if flip_x < 0 {
+        sprite += width - 1;
+    }
+    if flip_y < 0 {
+        sprite += (height - 1) * width;
+    }
+
+    let spriteRow = sprite + x0 * flip_x + y0 * flip_y * width;
+    let screenRow = x + x0 + (y + y0) * 320;
+
+    loop yloop {
+        let lx = 0;
+        loop xloop {
+            let lazy col = (spriteRow + lx * flip_x)?0;
+            if col != trans {
+                (screenRow + lx)?120 = col;
+            }
+            branch_if (lx +:= 1) < numCols: xloop;
+        }
+        spriteRow += width * flip_y;
+        screenRow += 320;
+        branch_if numRows -:= 1: yloop;
+    }
+}
+
+export fn grabSprite(sprite: i32, size: i32, x: i32, y: i32, control: i32) {
+    let lazy width = size & 65535;
+    let lazy height = select(size >> 16, size >> 16, width);
+
+    let lazy x0 = select(x < 0, -x, 0);
+    let lazy x1 = select(x + width > 320, 320 - x, width);
+    let lazy y0 = select(y < 0, -y, 0);
+    let lazy y1 = select(y + height > 240, 240 - y, height);
+
+    let lazy numRows = y1 - y0;
+    let lazy numCols = x1 - x0;
+    if numRows <= 0 | numCols <= 0 {
+        return;
+    }
+
+    let trans = (control & 511) - 256;
+    let lazy flip_x = 1 - ((control >> 8) & 2);
+    let lazy flip_y = 1 - ((control >> 9) & 2);
+    if flip_x < 0 {
+        sprite += width - 1;
+    }
+    if flip_y < 0 {
+        sprite += (height - 1) * width;
+    }
+
+    let spriteRow = sprite + x0 * flip_x + y0 * flip_y * width;
+    let screenRow = x + x0 + (y + y0) * 320;
+
+    loop yloop {
+        let lx = 0;
+        loop xloop {
+            let lazy col = (screenRow + lx)?120;
+            if col != trans {
+                (spriteRow + lx * flip_x)?0 = col;
+            }
+            branch_if (lx +:= 1) < numCols: xloop;
+        }
+        spriteRow += width * flip_y;
+        screenRow += 320;
+        branch_if numRows -:= 1: yloop;
+    }
+}
+
 //////////
 // TEXT //
 //////////

site/content/docs.md

@@ -146,13 +146,13 @@ Fills the circle at `cx, cy` and with `radius` with the given color index.
 
 (Sets all pixels where the pixel center lies inside the circle.)
 
-### fn rectangle_outline(x: f32, y: f32, w: f32, h: f32, color: i32)
+### fn rectangleOutline(x: f32, y: f32, w: f32, h: f32, color: i32)
 
 Draws a one pixel outline on the inside of the given rectangle.
 
 (Draws the outermost pixels that are still inside the rectangle area.)
 
-### fn circle_outline(cx: f32, cy: f32, radius: f32, color: i32)
+### fn circleOutline(cx: f32, cy: f32, radius: f32, color: i32)
 
 Draws a one pixel outline on the inside of the given circle.
 
@@ -162,6 +162,21 @@ Draws a one pixel outline on the inside of the given circle.
 
 Draws a line from `x1,y1` to `x2,y2` in the given color index.
 
+### fn blitSprite(spriteData: i32, size: i32, x: i32, y: i32, control: i32)
+
+Copies the pixel data at `spriteData` onto the screen at `x`, `y`. The size of the sprite is passed as `width | (height << 16)`.
+If the height is given as 0, the sprite is is treated as square (width x width).
+
+The control parameter controls masking and flipping of the sprite:
+* bits 0-7: color mask index
+* bit 8: switch on masked blit (pixel with color mask index are treated as transparent)
+* bit 9: flip sprite x
+* bit 10: flip sprite y
+
+### fn grabSprite(spriteData: i32, size: i32, x: i32, y: i32, control: i32)
+
+Copies the pixel data on the screen at `x`, `y` to `spriteData`. Parameters are exactly the same as `blitSprite`.
+
 ## Input
 
 MicroW8 provides input from a gamepad with one D-Pad and 4 buttons, or a keyboard emulation thereof.

src/run_native.rs

@@ -181,10 +181,12 @@ impl super::Runtime for MicroW8 {
         if let Some(mut instance) = self.instance.take() {
             let time = (now - instance.start_time).as_millis() as i32;
             let next_frame = {
-                let offset = ((time as u32 as i64 * 6) % 100 - 50) / 6;
-                let max = now + Duration::from_millis(17);
-                let next_center = now + Duration::from_millis((16 - offset) as u64);
-                next_center.min(max)
+                let frame = (time as u32 as u64 * 6 / 100) as u32;
+                let cur_offset = (time as u32).wrapping_sub((frame as u64 * 100 / 6) as u32);
+                let next_time =
+                    ((frame as u64 + 1) * 100 / 6 + cur_offset.max(1).min(4) as u64) as u32;
+                let offset = next_time.wrapping_sub(time as u32);
+                now + Duration::from_millis(offset as u64)
             };
 
             {

uw8-tool/src/base_module.rs

@@ -152,14 +152,14 @@ impl BaseModule {
         add_function(
             &mut functions,
             &type_map,
-            "rectangle_outline",
+            "rectangleOutline",
             &[F32, F32, F32, F32, I32],
             None,
         );
         add_function(
             &mut functions,
             &type_map,
-            "circle_outline",
+            "circleOutline",
             &[F32, F32, F32, I32],
             None,
         );
@@ -169,6 +169,21 @@ impl BaseModule {
         add_function(&mut functions, &type_map, "playNote", &[I32, I32], None);
         add_function(&mut functions, &type_map, "sndGes", &[I32], Some(F32));
 
+        add_function(
+            &mut functions,
+            &type_map,
+            "blitSprite",
+            &[I32, I32, I32, I32, I32],
+            None,
+        );
+        add_function(
+            &mut functions,
+            &type_map,
+            "grabSprite",
+            &[I32, I32, I32, I32, I32],
+            None,
+        );
+
         for i in functions.len()..64 {
             add_function(
                 &mut functions,

uw8-tool/src/filter_exports.rs

@@ -1,13 +1,17 @@
-use std::path::Path;
 use anyhow::Result;
+use std::path::Path;
 
 pub fn filter_exports(in_path: &Path, out_path: &Path) -> Result<()> {
     let mut module = walrus::Module::from_file(in_path)?;
 
-    let exports_to_delete: Vec<_> = module.exports.iter().filter_map(|export| match export.name.as_str() {
-        "upd" => None,
-        _ => Some(export.id())
-    }).collect();
+    let exports_to_delete: Vec<_> = module
+        .exports
+        .iter()
+        .filter_map(|export| match export.name.as_str() {
+            "upd" | "snd" | "start" => None,
+            _ => Some(export.id()),
+        })
+        .collect();
 
     for id in exports_to_delete {
         module.exports.delete(id);

web/src/microw8.js

@@ -274,7 +274,7 @@ export default function MicroW8(screen, config = {}) {
     
                 try {
                     let restart = false;
-                    let thisFrame;
+                    let nextFrame = 0;
                     if (!isPaused) {
                         let gamepads = navigator.getGamepads();
                         let gamepad = 0;
@@ -321,13 +321,12 @@ export default function MicroW8(screen, config = {}) {
                         }
                         canvasCtx.putImageData(imageData, 0, 0);
 
-                        let timeOffset = ((time * 6) % 100 - 50) / 6;
-                        thisFrame = startTime + time - timeOffset / 8;
-                    } else {
-                        thisFrame = Date.now();
+                        let thisFrame = Math.floor(time * 6 / 100);
+                        let timeOffset = time - thisFrame * 100 / 6;
+                        nextFrame = Math.ceil(startTime + (thisFrame + 1) * 100 / 6 + Math.min(4, timeOffset));
                     }
                     let now = Date.now();
-                    let nextFrame = Math.max(thisFrame + timePerFrame, now);
+                    nextFrame = Math.max(nextFrame, now);
     
                     if (restart) {
                         runModule(currentData);