First attempt at integration with nmouse and keyboard bindings

include/common/scene-helpers.h

@@ -20,4 +20,12 @@ struct wlr_scene_node *lab_wlr_scene_get_prev_node(struct wlr_scene_node *node);
 /* A variant of wlr_scene_output_commit() that respects wlr_output->pending */
 bool lab_wlr_scene_output_commit(struct wlr_scene_output *scene_output);
 
+enum magnify_dir {
+    MAGNIFY_INCREASE,
+    MAGNIFY_DECREASE
+};
+
+void magnify_toggle (void);
+void magnify_set_scale (enum magnify_dir dir);
+
 #endif /* LABWC_SCENE_HELPERS_H */

include/config/default-bindings.h

@@ -134,6 +134,9 @@ static struct key_combos {
 			.name = "command",
 			.value = "brightnessctl set 10%-",
 		},
+	}, {
+		.binding = "C-A-m",
+		.action = "ToggleMagnify",
 	}, {
 		.binding = NULL,
 	},
@@ -441,6 +444,24 @@ static struct mouse_combos {
 		.button = "Middle",
 		.event = "Press",
 		.action = "Raise",
+	}, {
+		.context = "All",
+		.button = "W-Up",
+		.event = "Scroll",
+		.action = "SetMagnification",
+		.attributes[0] = {
+			.name = "scale",
+			.value = "up",
+		},
+	}, {
+		.context = "All",
+		.button = "W-Down",
+		.event = "Scroll",
+		.action = "SetMagnification",
+		.attributes[0] = {
+			.name = "scale",
+			.value = "down",
+		},
 	}, {
 		.context = NULL,
 	},

include/config/rcxml.h

@@ -60,6 +60,9 @@ struct rcxml {
 	bool focus_follow_mouse_requires_movement;
 	bool raise_on_focus;
 
+	bool magnify;
+	int magnification;
+
 	/* theme */
 	char *theme_name;
 	int corner_radius;

src/action.c

@@ -13,6 +13,7 @@
 #include "common/parse-bool.h"
 #include "common/spawn.h"
 #include "common/string-helpers.h"
+#include "common/scene-helpers.h"
 #include "debug.h"
 #include "labwc.h"
 #include "menu/menu.h"
@@ -110,6 +111,8 @@ enum action_type {
 	ACTION_TYPE_SHADE,
 	ACTION_TYPE_UNSHADE,
 	ACTION_TYPE_TOGGLE_SHADE,
+	ACTION_TYPE_TOGGLE_MAGNIFY,
+	ACTION_TYPE_SET_MAGNIFICATION
 };
 
 const char *action_names[] = {
@@ -163,6 +166,8 @@ const char *action_names[] = {
 	"Shade",
 	"Unshade",
 	"ToggleShade",
+	"ToggleMagnify",
+	"SetMagnification",
 	NULL
 };
 
@@ -415,6 +420,12 @@ action_arg_from_xml_node(struct action *action, const char *nodename, const char
 			goto cleanup;
 		}
 		break;
+	case ACTION_TYPE_SET_MAGNIFICATION:
+		if (!strcmp(argument, "scale")) {
+			action_arg_add_str(action, argument, content);
+			goto cleanup;
+		}
+		break;
 	}
 
 	wlr_log(WLR_ERROR, "Invalid argument for action %s: '%s'",
@@ -1046,6 +1057,17 @@ actions_run(struct view *activator, struct server *server,
 				view_set_shade(view, false);
 			}
 			break;
+		case ACTION_TYPE_TOGGLE_MAGNIFY:
+			magnify_toggle();
+			break;
+		case ACTION_TYPE_SET_MAGNIFICATION:
+			const char *dir = action_get_str(action, "scale", NULL);
+			if (!strcmp(dir, "up")) {
+				magnify_set_scale(MAGNIFY_INCREASE);
+			} else if (!strcmp(dir, "down")) {
+				magnify_set_scale(MAGNIFY_DECREASE);
+			}
+			break;
 		case ACTION_TYPE_INVALID:
 			wlr_log(WLR_ERROR, "Not executing unknown action");
 			break;

src/common/scene-helpers.c

@@ -5,6 +5,12 @@
 #include <wlr/types/wlr_scene.h>
 #include <wlr/util/log.h>
 #include "common/scene-helpers.h"
+#include "labwc.h"
+
+#include <wlr/render/pass.h>
+#include <wlr/types/wlr_buffer.h>
+#include <wlr/render/drm_format_set.h>
+#include "common/macros.h"
 
 struct wlr_surface *
 lab_wlr_surface_from_node(struct wlr_scene_node *node)
@@ -34,6 +40,218 @@ lab_wlr_scene_get_prev_node(struct wlr_scene_node *node)
 	return prev;
 }
 
+
+/* TODO: move to rc. (or theme?) settings */
+#define magnifier_border 1      /* in pixels */
+#define magnifier_crop_size 100 /* how many pixels in each direction of the cursor */
+
+static void
+magnify(struct output *output, struct wlr_buffer *output_buffer, struct wlr_box *damage)
+{
+	/* Reuse a single scratch buffer */
+	static struct wlr_buffer *tmp_buffer = NULL;
+	static struct wlr_texture *tmp_texture = NULL;
+
+	/* TODO: This looks way too complicated to just get the used format */
+	struct wlr_drm_format wlr_drm_format = {0};
+	struct wlr_shm_attributes shm_attribs = {0};
+	struct wlr_dmabuf_attributes dma_attribs = {0};
+	if (wlr_buffer_get_dmabuf(output_buffer, &dma_attribs)) {
+		wlr_drm_format.format = dma_attribs.format;
+		wlr_drm_format.len = 1;
+		wlr_drm_format.modifiers = &dma_attribs.modifier;
+	} else if (wlr_buffer_get_shm(output_buffer, &shm_attribs)) {
+		wlr_drm_format.format = shm_attribs.format;
+	} else {
+		wlr_log(WLR_ERROR, "Failed to read buffer format");
+		return;
+	}
+
+	/* Fetch scale-adjusted cursor coordinates */
+	struct server *server = output->server;
+	struct wlr_cursor *cursor = server->seat.cursor;
+	double ox = cursor->x;
+	double oy = cursor->y;
+	wlr_output_layout_output_coords(server->output_layout, output->wlr_output, &ox, &oy);
+	ox *= output->wlr_output->scale;
+	oy *= output->wlr_output->scale;
+
+	/* TODO: refactor, to use rc. settings */
+	int width = magnifier_crop_size * 2 + 1;
+	int height = width;
+	double x = ox - magnifier_crop_size;
+	double y = oy - magnifier_crop_size;
+	double cropped_width = width;
+	double cropped_height = height;
+	double dst_x = 0;
+	double dst_y = 0;
+
+	/* Ensure everything is kept within output boundaries */
+	if (x < 0) {
+		cropped_width += x;
+		dst_x = x * -1;
+		x = 0;
+	}
+	if (y < 0) {
+		cropped_height += y;
+		dst_y = y * -1;
+		y = 0;
+	}
+	cropped_width = MIN(cropped_width, (double)output_buffer->width - x);
+	cropped_height = MIN(cropped_height, (double)output_buffer->height - y);
+
+	/* (Re)create the temporary buffer if required */
+	if (tmp_buffer && (tmp_buffer->width != width || tmp_buffer->height != height)) {
+		wlr_log(WLR_ERROR, "tmp buffer size changed, dropping");
+		assert(tmp_texture);
+		wlr_texture_destroy(tmp_texture);
+		wlr_buffer_drop(tmp_buffer);
+		tmp_buffer = NULL;
+		tmp_texture = NULL;
+	}
+	if (!tmp_buffer) {
+		tmp_buffer = wlr_allocator_create_buffer(
+			server->allocator, width, height, &wlr_drm_format);
+	}
+	if (!tmp_buffer) {
+		wlr_log(WLR_ERROR, "Failed to allocate temporary magnifier buffer");
+		return;
+	}
+
+	/* Extract source region into temporary buffer */
+
+	struct wlr_render_pass *tmp_render_pass = wlr_renderer_begin_buffer_pass(
+		server->renderer, tmp_buffer, NULL);
+
+	/* FIXME, try to re-use the existing output texture instead */
+	wlr_buffer_lock(output_buffer);
+	struct wlr_texture *output_texture = wlr_texture_from_buffer(
+		server->renderer, output_buffer);
+	assert(output_texture);
+
+	struct wlr_render_texture_options opts = {
+		.texture = output_texture,
+		.src_box = (struct wlr_fbox) {
+			x, y, cropped_width, cropped_height },
+		.dst_box = (struct wlr_box) {
+			dst_x, dst_y, cropped_width, cropped_height },
+		.alpha = NULL,
+	};
+	wlr_render_pass_add_texture(tmp_render_pass, &opts);
+	if (!wlr_render_pass_submit(tmp_render_pass)) {
+		wlr_log(WLR_ERROR, "Failed to extract magnifier source region");
+		wlr_texture_destroy(output_texture);
+		goto cleanup;
+	}
+	wlr_texture_destroy(output_texture);
+
+	/* Render to the output buffer itself */
+	tmp_render_pass = wlr_renderer_begin_buffer_pass(
+		server->renderer, output_buffer, NULL);
+
+	/* Borders */
+	struct wlr_box border_box = {
+		.x = ox - (width / 2 + magnifier_border) * rc.magnification,
+		.y = oy - (height / 2 + magnifier_border) * rc.magnification,
+		.width = (width + magnifier_border * 2) * rc.magnification,
+		.height = (height + magnifier_border * 2) * rc.magnification,
+	};
+	struct wlr_render_rect_options bg_opts = {
+		.box = border_box,
+		/* TODO: make this a rc. setting */
+		.color = (struct wlr_render_color) { 1, 0, 0, 1 },
+		.clip = NULL,
+	};
+	wlr_render_pass_add_rect(tmp_render_pass, &bg_opts);
+
+	/* Paste the magnified result back into the output buffer */
+	if (!tmp_texture) {
+		tmp_texture = wlr_texture_from_buffer(server->renderer, tmp_buffer);
+		assert(tmp_texture);
+	}
+	opts = (struct wlr_render_texture_options) {
+		.texture = tmp_texture,
+		.src_box = (struct wlr_fbox) { 0, 0, width, height },
+		.dst_box = (struct wlr_box) {
+			.x = ox - (width / 2) * rc.magnification,
+			.y = oy - (height / 2) * rc.magnification,
+			.width = width * rc.magnification,
+			.height = height * rc.magnification,
+		},
+		.alpha = NULL,
+		.clip = NULL,
+		//.filter_mode = WLR_SCALE_FILTER_NEAREST,
+		.filter_mode = WLR_SCALE_FILTER_BILINEAR,
+	};
+	wlr_render_pass_add_texture(tmp_render_pass, &opts);
+	if (!wlr_render_pass_submit(tmp_render_pass)) {
+		wlr_log(WLR_ERROR, "Failed to submit render pass");
+		goto cleanup;
+	}
+
+	/* And finally mark the extra damage */
+	*damage = border_box;
+	damage->width += 1;
+	damage->height += 1;
+
+cleanup:
+	wlr_buffer_unlock(output_buffer);
+}
+
+static bool
+output_wants_magnification(struct output *output)
+{
+	static double x = -1;
+	static double y = -1;
+	struct wlr_cursor *cursor = output->server->seat.cursor;
+	if (!rc.magnify) {
+		x = -1;
+		y = -1;
+		return false;
+	}
+	if (cursor->x == x && cursor->y == y) {
+		return false;
+	}
+	x = cursor->x;
+	y = cursor->y;
+	return output_nearest_to_cursor(output->server) == output;
+}
+
+/*
+ * Toggles magnification on and off
+ */
+
+void magnify_toggle (void)
+{
+	if (rc.magnify) {
+		rc.magnify = false;
+	} else {
+		rc.magnify = true;
+	}
+}
+
+/*
+ * Increases and decreases magnification scale
+ */
+
+void magnify_set_scale (enum magnify_dir dir)
+{
+	if (dir == MAGNIFY_INCREASE) {
+		if (rc.magnify) {
+			rc.magnification++;
+		} else {
+			rc.magnify = true;
+			rc.magnification = 2;
+		}
+	} else {
+		if (rc.magnify && rc.magnification > 2) {
+			rc.magnification--;
+		} else {
+			rc.magnify = false;
+		}
+	}
+}
+
 /*
  * This is a copy of wlr_scene_output_commit()
  * as it doesn't use the pending state at all.
@@ -44,16 +262,31 @@ lab_wlr_scene_output_commit(struct wlr_scene_output *scene_output)
 	assert(scene_output);
 	struct wlr_output *wlr_output = scene_output->output;
 	struct wlr_output_state *state = &wlr_output->pending;
+	struct output *output = wlr_output->data;
+	bool wants_magnification = output_wants_magnification(output);
+	static bool last_mag = false;
+	static int last_scale = 2;
 
 	if (!wlr_output->needs_frame && !pixman_region32_not_empty(
-			&scene_output->damage_ring.current)) {
+			&scene_output->damage_ring.current) && !wants_magnification
+			&& last_mag != rc.magnify && last_scale != rc.magnification) {
 		return false;
 	}
+
+	last_mag = rc.magnify;
+	last_scale = rc.magnification;
+
 	if (!wlr_scene_output_build_state(scene_output, state, NULL)) {
 		wlr_log(WLR_ERROR, "Failed to build output state for %s",
 			wlr_output->name);
 		return false;
 	}
+
+	struct wlr_box additional_damage = {0};
+	if (state->buffer && rc.magnify) {
+		magnify(output, state->buffer, &additional_damage);
+	}
+
 	if (!wlr_output_commit(wlr_output)) {
 		wlr_log(WLR_INFO, "Failed to commit output %s",
 			wlr_output->name);
@@ -66,5 +299,9 @@ lab_wlr_scene_output_commit(struct wlr_scene_output *scene_output)
 	 * again.
 	 */
 	wlr_damage_ring_rotate(&scene_output->damage_ring);
+
+	if (!wlr_box_empty(&additional_damage)) {
+		wlr_damage_ring_add_box(&scene_output->damage_ring, &additional_damage);
+	}
 	return true;
 }

src/config/rcxml.c

@@ -1204,6 +1204,8 @@ rcxml_init(void)
 	rc.focus_follow_mouse = false;
 	rc.focus_follow_mouse_requires_movement = true;
 	rc.raise_on_focus = false;
+	rc.magnify = false;
+	rc.magnification = 2;
 
 	rc.doubleclick_time = 500;
 	rc.scroll_factor = 1.0;