From 6d766d6dd9177ececb14ebfe2ac68cc581eeeb44 Mon Sep 17 00:00:00 2001
From: ubq323 <ubq323@ubq323.website>
Date: Fri, 22 Mar 2024 23:52:56 +0000
Subject: movement, multiple surfaces (sort of)

---
 drawing.ha | 41 +++++++++++++++++++++++++++-----------
 main.ha    | 66 +++++++++++++++++++++++++++++++++-----------------------------
 2 files changed, 65 insertions(+), 42 deletions(-)

diff --git a/drawing.ha b/drawing.ha
index ff2aa71..804aee4 100644
--- a/drawing.ha
+++ b/drawing.ha
@@ -1,14 +1,13 @@
 use sdl2;
 
-
 // 2d position, x and y
-type pos = (int, int);
+type pos = (i32, i32);
 
 type drawing_state = struct {
 	// is the mouse button held down?
 	drawing: bool,
 	pos: pos,
-	picture: picture,
+	picture: *picture,
 };
 
 type picture = struct {
@@ -16,6 +15,7 @@ type picture = struct {
 	w: size,
 	h: size,
 };
+
 // Returns array index of the pixel at position pos.
 // Bounds check happens in here instead of using a slice type, so
 // that it's easier to remove later.
@@ -29,22 +29,42 @@ fn pidx(pic: *picture, pos: pos) size = {
 
 	return xs + pic.w*ys;
 };
-fn pic_set(pic: *picture, pos: pos, val: u32) void = pic.d[pidx(pic,pos)] = val;
+
+fn pic_set(pic: *picture, pos: pos, val: u32) void =
+	pic.d[pidx(pic,pos)] = val;
+
 fn picture_from_surface(surf: *sdl2::SDL_Surface) picture = picture {
 	w = surf.w: size,
 	h = surf.h: size,
 	d = (surf.pixels as *opaque: *[*]u32),
 };
 
-fn min(a: int, b: int) int = if (a<b) a else b;
-fn max(a: int, b: int) int = if (a<b) b else a;
+fn clear_picture(pic: *picture, color: u32) void = {
+	for (let i = 0z; i < pic.w*pic.h; i+=1) pic.d[i] = color;
+};
 
-fn circle(dstate: *drawing_state, c: pos, r: int, color: u32) void = {
+fn outline_picture(pic: *picture) void = {
+	for (let x = 0; x:size < pic.w; x+=1) {
+		pic_set(pic, (x, 0), 0);
+		pic_set(pic, (x, pic.h:int-1), 0);
+	};
+	for (let y = 0; y:size < pic.h; y+=1) {
+		pic_set(pic, (0, y), 0);
+		pic_set(pic, (pic.w:int-1, y), 0);
+	};
+};
+
+fn min(a: i32, b: i32) i32 = if (a<b) a else b;
+fn max(a: i32, b: i32) i32 = if (a<b) b else a;
+
+// Draws a circle onto the dstate's picture, at given position radius color
+// Clips at the boundaries of the picture to avoid overflow.
+fn circle(dstate: *drawing_state, c: pos, r: i32, color: u32) void = {
 	const (cx,cy) = c;
 	const ymin = max(0, cy-r);
-	const ymax = min(dstate.picture.h:int-1, cy+r);
+	const ymax = min(dstate.picture.h:i32-1, cy+r);
 	const xmin = max(0, cx-r);
-	const xmax = min(dstate.picture.w:int-1, cx+r);
+	const xmax = min(dstate.picture.w:i32-1, cx+r);
 
 	const r2 = r*r + r;
 
@@ -53,11 +73,10 @@ fn circle(dstate: *drawing_state, c: pos, r: int, color: u32) void = {
 		for (let x = xmin; x<=xmax; x+=1) {
 			const xd = x-cx;
 			if (yd*yd + xd*xd <= r2) {
-				pic_set(&dstate.picture, (x,y), color);
+				pic_set(dstate.picture, (x,y), color);
 			};
 		};
 	};
-
 };
 
 fn do_drawing(dstate: *drawing_state) void = {
diff --git a/main.ha b/main.ha
index ca0c68e..9035053 100644
--- a/main.ha
+++ b/main.ha
@@ -1,37 +1,32 @@
 use fmt;
 use sdl2;
+use math;
 
 export fn main() void = {
 	sdl2::SDL_Init(sdl2::SDL_INIT_VIDEO)!;
 	defer sdl2::SDL_Quit();
 
-	fmt::println(size(i32), size(i64), size(int), size(size))!;
-
-
 	const win = sdl2::SDL_CreateWindow("hi", sdl2::SDL_WINDOWPOS_UNDEFINED, sdl2::SDL_WINDOWPOS_UNDEFINED, 640, 480, sdl2::SDL_WindowFlags::NONE)!;
 	defer sdl2::SDL_DestroyWindow(win);
 
 	const wsurf = sdl2::SDL_GetWindowSurface(win)!;
-	const format = wsurf.format;
-	assert(format.bytesperpixel == 4, "can only work with u32 pixels");
-	fmt::printfln("got format {}. bytes per pixel {}. r{:x} g{:x} b{:x} a{:x}",
-		format.format, format.bytesperpixel, format.rmask, format.gmask, format.bmask, format.amask)!;
-	fmt::printfln("red: {:x} green {:x} blue {:x}",
-		sdl2::SDL_MapRGB(format, 255, 0, 0),
-		sdl2::SDL_MapRGB(format, 0, 255, 0),
-		sdl2::SDL_MapRGB(format, 0, 0, 255))!;
-	fmt::println(wsurf.w * wsurf.h)!;
-	fmt::println(sdl2::SDL_GetPixelFormatName(format.format))!;
+
+	const xsurf = sdl2::SDL_CreateRGBSurface(0,
+		512, 512, 32, 0xff0000, 0xff00, 0xff, 0)!;
 
 	let dstate = drawing_state {
 		drawing = false,
 		pos = (0,0),
-		picture = picture_from_surface(wsurf)
+		picture = &picture_from_surface(xsurf)
 	};
 
+	let camera_pos: pos = (25, 50);
+
+	clear_picture(dstate.picture, 0xffffff);
+	outline_picture(dstate.picture);
 
 	let quit = false;
-	let n = 0z;
+	let n = 0;
 	let lasttime = sdl2::SDL_GetTicks();
 	for (!quit) {
 		let ev = sdl2::event { ... };
@@ -52,28 +47,37 @@ export fn main() void = {
 			case => void;
 		};
 
-		do_drawing(&dstate);
-
-
-		// if (drawing) {
-		// 	circle(pic, mousex, mousey, 5, 0x00ffff);
-		// };
+		movement(&camera_pos);
 
-		// circle(pic, 100, 100, n:int, 0xff0000);
+		do_drawing(&dstate);
+		
+		sdl2::SDL_BlitSurface(xsurf, null, wsurf, &sdl2::SDL_Rect {
+			x = camera_pos.0, y = camera_pos.1, ...
+		})!;
 
 		sdl2::SDL_UpdateWindowSurface(win)!;
 		n += 1;
 		sdl2::SDL_Delay(1000/60);
-
-		// if (n % 100 == 0) {
-		// 	const thistime = sdl2::SDL_GetTicks();
-		// 	const dt = (thistime - lasttime): f64;
-		// 	lasttime = thistime;
-		// 	const dt = dt / 100.0;
-		// 	const fps = 1000.0/dt;
-		// 	fmt::printfln("fps: {}",fps)!;
-		// };
 	};
 };
 
+def SPEED = 17;
+def DIAG_SPEED = 12;  // thereabouts
+
+fn movement(pos: *pos) void = {
+	const kb = sdl2::SDL_GetKeyboardState();
+	let dx = 0;
+	let dy = 0;
+	if (kb[sdl2::SDL_Scancode::W]) dy -= 1;
+	if (kb[sdl2::SDL_Scancode::S]) dy += 1;
+	if (kb[sdl2::SDL_Scancode::A]) dx -= 1;
+	if (kb[sdl2::SDL_Scancode::D]) dx += 1;
+
+	let speed = SPEED;
+	if (dx != 0 && dy != 0) speed = DIAG_SPEED;
+
+	pos.0 += dx * speed;
+	pos.1 += dy * speed;
+};
+
 
-- 
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