MR 3421 change: remove scale param, always scale to dst width or height

examples/mirror.c

@@ -27,9 +27,7 @@ static const char usage[] =
 "usage: mirror <src> <dst>\n"
 "    e.g. mirror eDP-1 HDMI-A-1\n"
 "keys:\n"
-"    a: WLR_MIRROR_SCALE_ASPECT\n"
+"    m: toggle mirroring\n"
-"    f: WLR_MIRROR_SCALE_FULL\n"
-"    c: WLR_MIRROR_SCALE_CENTER\n"
 "    esc: exit\n";
 
 struct sample_state {
@@ -88,7 +86,7 @@ struct sample_keyboard {
 	struct wl_listener destroy;
 };
 
-void start_mirror(struct sample_state *state, enum wlr_mirror_scale scale);
+void start_mirror(struct sample_state *state);
 void end_mirror(struct sample_state *state);
 void handle_mirror_ready(struct wl_listener *listener, void *data);
 void handle_mirror_destroy(struct wl_listener *listener, void *data);
@@ -104,7 +102,7 @@ void handle_keyboard_destroy(struct wl_listener *listener, void *data);
 void render_rects(struct wlr_renderer *renderer, struct sample_output *output, float colour[]);
 
 // start a mirror session
-void start_mirror(struct sample_state *state, enum wlr_mirror_scale scale) {
+void start_mirror(struct sample_state *state) {
 	struct sample_output *output_src = state->output_src;
 	struct sample_output *output_dst = state->output_dst;
 	if (!output_src || !output_dst) {
@@ -124,7 +122,6 @@ void start_mirror(struct sample_state *state, enum wlr_mirror_scale scale) {
 	mirror->dy = 1;
 
 	// params immutable over the session
-	mirror->params.scale = scale;
 	mirror->params.overlay_cursor = true;
 	mirror->params.output_dst = state->output_dst->wlr_output;
 
@@ -300,8 +297,6 @@ void handle_keyboard_key(struct wl_listener *listener, void *data) {
 	uint32_t keycode = event->keycode + 8;
 	const xkb_keysym_t *syms;
 	int nsyms = xkb_state_key_get_syms(keyboard->device->keyboard->xkb_state, keycode, &syms);
-	bool start_end_mirror = false;
-	enum wlr_mirror_scale scale;
 
 	for (int i = 0; i < nsyms; i++) {
 		xkb_keysym_t sym = syms[i];
@@ -310,31 +305,18 @@ void handle_keyboard_key(struct wl_listener *listener, void *data) {
 				case XKB_KEY_Escape:
 					wl_display_terminate(state->display);
 					break;
-				case XKB_KEY_f:
+				case XKB_KEY_m:
-					scale = WLR_MIRROR_SCALE_FULL;
+					if (state->mirror) {
-					start_end_mirror = true;
+						end_mirror(state);
-					break;
+					} else {
-				case XKB_KEY_a:
+						start_mirror(state);
-					scale = WLR_MIRROR_SCALE_ASPECT;
+					}
-					start_end_mirror = true;
-					break;
-				case XKB_KEY_c:
-					scale = WLR_MIRROR_SCALE_CENTER;
-					start_end_mirror = true;
 					break;
 				default:
 					break;
 			}
 		}
 	}
-
-	if (start_end_mirror) {
-		if (state->mirror) {
-			end_mirror(state);
-		} else {
-			start_mirror(state, scale);
-		}
-	}
 }
 
 void handle_output_destroy(struct wl_listener *listener, void *data) {

include/wlr/types/wlr_mirror.h

@@ -18,6 +18,8 @@
  * Allows mirroring: rendering some contents of one output (the src) on another
  * output (the dst). dst is fixed for the duration of the session, src may vary.
  *
+ * Content will be scaled to fit the width or height of dst.
+ *
  * On output_srcs precommit, wlr_mirror::ready is emitted. The compositor may
  * call wlr_mirror_request_ to request to render a frame on dst.
  *
@@ -31,29 +33,11 @@
  *   wlr_mirror_destroy
  */
 
-enum wlr_mirror_scale {
-	/**
-	 * src will be stretched to cover dst, distorting if necessary.
-	 */
-	WLR_MIRROR_SCALE_FULL,
-	/**
-	 * src will be stretched to the width or the height of dst, preserving the
-	 * aspect ratio.
-	 */
-	WLR_MIRROR_SCALE_ASPECT,
-	/**
-	 * src will be rendered 1:1 at the center of dst. Content may be lost.
-	 */
-	WLR_MIRROR_SCALE_CENTER,
-};
-
 /**
  * Immutable over session.
  */
 struct wlr_mirror_params {
 
-	enum wlr_mirror_scale scale;
-
 	/**
 	 * Render the src cursor on dst.
 	 */

types/wlr_mirror.c

@@ -127,11 +127,10 @@ static void calculate_absolute_box(struct wlr_box *absolute,
 }
 
 /**
- * Position a box according to the scale method. It will be rotated from src
+ * Position a box scaled to fit the width or height of dst. It will be rotated
- * to dst.
+ * from src to dst.
  */
 static void calculate_dst_box(struct wlr_fbox *box_dst,
-		enum wlr_mirror_scale scale_method,
 		enum wl_output_transform transform_src,
 		enum wl_output_transform transform_dst,
 		int32_t width_src, int32_t height_src,
@@ -146,46 +145,24 @@ static void calculate_dst_box(struct wlr_fbox *box_dst,
 	rotate_v_h(&width_src_rotated, &height_src_rotated, transform_src, width_src, height_src);
 	rotate_v_h(&width_dst_rotated, &height_dst_rotated, transform_dst, width_dst, height_dst);
 
-	switch (scale_method) {
+	if (width_dst_rotated * height_src_rotated > height_dst_rotated * width_src_rotated) {
-		case WLR_MIRROR_SCALE_CENTER:
+		// expand to dst height
-			box_dst->width = width_src;
+		width_scaled = ((float) width_src_rotated) * height_dst_rotated / height_src_rotated;
-			box_dst->height = height_src;
+		height_scaled = height_dst_rotated;
-			box_dst->x = (((float) width_dst_rotated) - width_src_rotated) / 2;
+	} else {
-			box_dst->y = (((float) height_dst_rotated) - height_src_rotated) / 2;
+		// expand to dst width
-			break;
+		width_scaled = width_dst_rotated;
-		case WLR_MIRROR_SCALE_ASPECT:
+		height_scaled = ((float) height_src_rotated) * width_dst_rotated / width_src_rotated;
-			if (width_dst_rotated * height_src_rotated > height_dst_rotated * width_src_rotated) {
-				// expand to dst height
-				width_scaled = ((float) width_src_rotated) * height_dst_rotated / height_src_rotated;
-				height_scaled = height_dst_rotated;
-			} else {
-				// expand to dst width
-				width_scaled = width_dst_rotated;
-				height_scaled = ((float) height_src_rotated) * width_dst_rotated / width_src_rotated;
-			}
-			if (src_rotated) {
-				box_dst->width = height_scaled;
-				box_dst->height = width_scaled;
-			} else {
-				box_dst->width = width_scaled;
-				box_dst->height = height_scaled;
-			}
-			box_dst->x = (((float) width_dst_rotated) - width_scaled) / 2;
-			box_dst->y = (((float) height_dst_rotated) - height_scaled) / 2;
-			break;
-		case WLR_MIRROR_SCALE_FULL:
-		default:
-			if (src_rotated) {
-				box_dst->width = height_dst_rotated;
-				box_dst->height = width_dst_rotated;
-			} else {
-				box_dst->width = width_dst_rotated;
-				box_dst->height = height_dst_rotated;
-			}
-			box_dst->x = 0;
-			box_dst->y = 0;
-			break;
 	}
+	if (src_rotated) {
+		box_dst->width = height_scaled;
+		box_dst->height = width_scaled;
+	} else {
+		box_dst->width = width_scaled;
+		box_dst->height = height_scaled;
+	}
+	box_dst->x = (((float) width_dst_rotated) - width_scaled) / 2;
+	box_dst->y = (((float) height_dst_rotated) - height_scaled) / 2;
 }
 
 /**
@@ -340,7 +317,7 @@ static void output_dst_handle_frame(struct wl_listener *listener, void *data) {
 
 		// scale and position a box for the dst
 		struct wlr_fbox fbox_dst = {0};
-		calculate_dst_box(&fbox_dst, state->params.scale,
+		calculate_dst_box(&fbox_dst,
 				output_src->transform, output_dst->transform,
 				box_src.width, box_src.height,
 				output_dst->width, output_dst->height);