Add wlr_output_layout implementation

An output layout consists of a mapping of outputs to their position in a global
coordinate system that usually cooresponds to the output position in physical
space in front of the user.

Add an example that allows configuration of an output layout and demonstrates
its boundaries with a bouncing image.

examples/meson.build

@@ -7,6 +7,7 @@ executable('rotation', 'rotation.c', dependencies: wlroots, link_with: lib_share
 executable('pointer', 'pointer.c', dependencies: wlroots, link_with: lib_shared)
 executable('touch', 'touch.c', dependencies: wlroots, link_with: lib_shared)
 executable('tablet', 'tablet.c', dependencies: wlroots, link_with: lib_shared)
+executable('output-layout', 'output-layout.c', dependencies: wlroots, link_with: lib_shared)
 
 compositor_src = [
   'compositor/main.c',

examples/output-layout.c

@@ -0,0 +1,276 @@
+#define _POSIX_C_SOURCE 199309L
+#define _XOPEN_SOURCE 500
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <string.h>
+#include <strings.h>
+#include <unistd.h>
+#include <wayland-server.h>
+#include <wayland-server-protocol.h>
+#include <xkbcommon/xkbcommon.h>
+#include <GLES2/gl2.h>
+#include <wlr/render/matrix.h>
+#include <wlr/render/gles2.h>
+#include <wlr/render.h>
+#include <wlr/util/log.h>
+#include <wlr/backend.h>
+#include <wlr/backend/session.h>
+#include <wlr/types/wlr_output_layout.h>
+#include <wlr/types/wlr_output.h>
+#include <wlr/types/wlr_keyboard.h>
+#include <math.h>
+#include "shared.h"
+#include "cat.h"
+
+struct sample_state {
+	struct wl_list config;
+	struct wlr_renderer *renderer;
+	struct wlr_texture *cat_texture;
+	struct wlr_output_layout *layout;
+	float x_offs, y_offs;
+	float x_vel, y_vel;
+	struct wlr_output *main_output;
+};
+
+struct output_config {
+	char *name;
+	enum wl_output_transform transform;
+	int x, y;
+	struct wl_list link;
+};
+
+static void handle_output_frame(struct output_state *output, struct timespec *ts) {
+	struct compositor_state *state = output->compositor;
+	struct sample_state *sample = state->data;
+	struct wlr_output *wlr_output = output->output;
+
+	int32_t width, height;
+	wlr_output_effective_resolution(wlr_output, &width, &height);
+
+	wlr_output_make_current(wlr_output);
+	wlr_renderer_begin(sample->renderer, wlr_output);
+
+	float matrix[16];
+
+	// transform global coordinates to local coordinates
+	int local_x = sample->x_offs;
+	int local_y = sample->y_offs;
+
+	wlr_output_layout_output_coords(sample->layout, output->output, &local_x,
+		&local_y);
+
+	wlr_texture_get_matrix(sample->cat_texture, &matrix,
+		&wlr_output->transform_matrix, local_x, local_y);
+	wlr_render_with_matrix(sample->renderer,
+		sample->cat_texture, &matrix);
+
+	wlr_renderer_end(sample->renderer);
+	wlr_output_swap_buffers(wlr_output);
+
+	if (output->output == sample->main_output) {
+		long ms = (ts->tv_sec - output->last_frame.tv_sec) * 1000 +
+			(ts->tv_nsec - output->last_frame.tv_nsec) / 1000000;
+		// how many seconds have passed since the last frame
+		float seconds = ms / 1000.0f;
+
+		// check for collisions and bounce
+		bool ur_collision = !wlr_output_layout_output_at(sample->layout,
+				sample->x_offs + 128, sample->y_offs);
+		bool ul_collision = !wlr_output_layout_output_at(sample->layout,
+				sample->x_offs, sample->y_offs);
+		bool ll_collision = !wlr_output_layout_output_at(sample->layout,
+				sample->x_offs, sample->y_offs + 128);
+		bool lr_collision = !wlr_output_layout_output_at(sample->layout,
+				sample->x_offs + 128, sample->y_offs + 128);
+		bool has_double_collision = false;
+
+		if ((ur_collision && ul_collision) || (lr_collision && ll_collision)) {
+			sample->y_vel *= -1;
+			has_double_collision = true;
+		}
+
+		if ((ll_collision && ul_collision) || (ur_collision && lr_collision)) {
+			sample->x_vel *= -1;
+			has_double_collision = true;
+		}
+
+		if (!has_double_collision &&
+				(ur_collision || ul_collision || lr_collision || ll_collision)) {
+			sample->x_vel *= -1;
+			sample->y_vel *= -1;
+		}
+
+		sample->x_offs += sample->x_vel * seconds;
+		sample->y_offs += sample->y_vel * seconds;
+	}
+}
+
+static void handle_output_add(struct output_state *output) {
+	struct sample_state *sample = output->compositor->data;
+
+	struct output_config *conf;
+	wl_list_for_each(conf, &sample->config, link) {
+		if (strcmp(conf->name, output->output->name) == 0) {
+			wlr_output_layout_add(sample->layout, output->output,
+					conf->x, conf->y);
+			wlr_output_transform(output->output, conf->transform);
+
+			if (!sample->main_output) {
+				sample->main_output = output->output;
+				sample->x_offs = conf->x + 20;
+				sample->y_offs = conf->y + 20;
+				sample->x_vel = 500;
+				sample->y_vel = 500;
+			}
+			wlr_log(L_DEBUG, "Adding output to layout: %s", output->output->name);
+		}
+
+	}
+}
+
+static void update_velocities(struct compositor_state *state,
+		float x_diff, float y_diff) {
+	struct sample_state *sample = state->data;
+	sample->x_vel += x_diff;
+	sample->y_vel += y_diff;
+}
+
+static void handle_keyboard_key(struct keyboard_state *kbstate,
+		xkb_keysym_t sym, enum wlr_key_state key_state) {
+	// NOTE: It may be better to simply refer to our key state during each frame
+	// and make this change in pixels/sec^2
+	// Also, key repeat
+	int delta = 75;
+	if (key_state == WLR_KEY_PRESSED) {
+		switch (sym) {
+		case XKB_KEY_Left:
+			update_velocities(kbstate->compositor, -delta, 0);
+			break;
+		case XKB_KEY_Right:
+			update_velocities(kbstate->compositor, delta, 0);
+			break;
+		case XKB_KEY_Up:
+			update_velocities(kbstate->compositor, 0, -delta);
+			break;
+		case XKB_KEY_Down:
+			update_velocities(kbstate->compositor, 0, delta);
+			break;
+		}
+	}
+}
+
+static void usage(const char *name, int ret) {
+	fprintf(stderr,
+		"usage: %s [-d <name> [-r <rotation> | -f]]*\n"
+		"\n"
+		" -o <output>    The name of the DRM display. e.g. DVI-I-1.\n"
+		" -r <rotation>  The rotation counter clockwise. Valid values are 90, 180, 270.\n"
+		" -x <position>  The X-axis coordinate position of this output in the layout.\n"
+		" -y <position>  The Y-axis coordinate position of this output in the layout.\n"
+		" -f             Flip the output along the vertical axis.\n", name);
+
+	exit(ret);
+}
+
+static void parse_args(int argc, char *argv[], struct wl_list *config) {
+	struct output_config *oc = NULL;
+
+	int c;
+	while ((c = getopt(argc, argv, "o:r:x:y:fh")) != -1) {
+		switch (c) {
+		case 'o':
+			oc = calloc(1, sizeof(*oc));
+			oc->name = optarg;
+			oc->transform = WL_OUTPUT_TRANSFORM_NORMAL;
+			wl_list_insert(config, &oc->link);
+			break;
+		case 'r':
+			if (!oc) {
+				fprintf(stderr, "You must specify an output first\n");
+				usage(argv[0], 1);
+			}
+
+			if (oc->transform != WL_OUTPUT_TRANSFORM_NORMAL
+					&& oc->transform != WL_OUTPUT_TRANSFORM_FLIPPED) {
+				fprintf(stderr, "Rotation for %s already specified\n", oc->name);
+				usage(argv[0], 1);
+			}
+
+			if (strcmp(optarg, "90") == 0) {
+				oc->transform += WL_OUTPUT_TRANSFORM_90;
+			} else if (strcmp(optarg, "180") == 0) {
+				oc->transform += WL_OUTPUT_TRANSFORM_180;
+			} else if (strcmp(optarg, "270") == 0) {
+				oc->transform += WL_OUTPUT_TRANSFORM_270;
+			} else {
+				fprintf(stderr, "Invalid rotation '%s'\n", optarg);
+				usage(argv[0], 1);
+			}
+			break;
+		case 'x':
+			if (!oc) {
+				fprintf(stderr, "You must specify an output first\n");
+				usage(argv[0], 1);
+			}
+			oc->x = strtol(optarg, NULL, 0);
+			break;
+		case 'y':
+			if (!oc) {
+				fprintf(stderr, "You must specify an output first\n");
+				usage(argv[0], 1);
+			}
+			oc->y = strtol(optarg, NULL, 0);
+			break;
+		case 'f':
+			if (!oc) {
+				fprintf(stderr, "You must specify an output first\n");
+				usage(argv[0], 1);
+			}
+
+			if (oc->transform >= WL_OUTPUT_TRANSFORM_FLIPPED) {
+				fprintf(stderr, "Flip for %s already specified\n", oc->name);
+				usage(argv[0], 1);
+			}
+
+			oc->transform += WL_OUTPUT_TRANSFORM_FLIPPED;
+			break;
+		case 'h':
+		case '?':
+			usage(argv[0], c != 'h');
+		}
+	}
+}
+
+int main(int argc, char *argv[]) {
+	struct sample_state state = {0};
+
+	state.layout = wlr_output_layout_init();
+
+	wl_list_init(&state.config);
+	parse_args(argc, argv, &state.config);
+
+	struct compositor_state compositor = { 0 };
+	compositor.data = &state;
+	compositor.output_add_cb = handle_output_add;
+	compositor.output_frame_cb = handle_output_frame;
+	compositor.keyboard_key_cb = handle_keyboard_key;
+	compositor_init(&compositor);
+
+	state.renderer = wlr_gles2_renderer_init(compositor.backend);
+	state.cat_texture = wlr_render_texture_init(state.renderer);
+	wlr_texture_upload_pixels(state.cat_texture, WL_SHM_FORMAT_ABGR8888,
+		cat_tex.width, cat_tex.width, cat_tex.height, cat_tex.pixel_data);
+
+	compositor_run(&compositor);
+
+	wlr_texture_destroy(state.cat_texture);
+	wlr_renderer_destroy(state.renderer);
+
+	wlr_output_layout_destroy(state.layout);
+
+	struct output_config *ptr, *tmp;
+	wl_list_for_each_safe(ptr, tmp, &state.config, link) {
+		free(ptr);
+	}
+}

include/wlr/types/wlr_output_layout.h

@@ -0,0 +1,40 @@
+#ifndef _WLR_TYPES_OUTPUT_LAYOUT_H
+#define _WLR_TYPES_OUTPUT_LAYOUT_H
+#include <wlr/types/wlr_output.h>
+#include <wayland-util.h>
+#include <stdbool.h>
+
+struct wlr_output_layout {
+    struct wl_list outputs;
+};
+
+struct wlr_output_layout_output {
+    struct wlr_output *output;
+    int x, y;
+    struct wl_list link;
+};
+
+struct wlr_output_layout *wlr_output_layout_init();
+
+void wlr_output_layout_destroy(struct wlr_output_layout *layout);
+
+struct wlr_output *wlr_output_layout_output_at(struct wlr_output_layout *layout,
+	double x, double y);
+
+void wlr_output_layout_add(struct wlr_output_layout *layout,
+    struct wlr_output *output, int x, int y);
+
+void wlr_output_layout_move(struct wlr_output_layout *layout,
+    struct wlr_output *output, int x, int y);
+
+void wlr_output_layout_remove(struct wlr_output_layout *layout,
+    struct wlr_output *output);
+
+/**
+ * Given x and y as pointers to global coordinates, adjusts them to local output
+ * coordinates relative to the given reference output.
+ */
+void wlr_output_layout_output_coords(struct wlr_output_layout *layout,
+    struct wlr_output *reference, int *x, int *y);
+
+#endif

types/meson.build

@@ -2,6 +2,7 @@ lib_wlr_types = static_library('wlr_types', files(
     'wlr_input_device.c',
     'wlr_keyboard.c',
     'wlr_output.c',
+    'wlr_output_layout.c',
     'wlr_pointer.c',
     'wlr_region.c',
     'wlr_seat.c',

types/wlr_output_layout.c

@@ -0,0 +1,104 @@
+#include <wlr/util/log.h>
+#include <wlr/types/wlr_output.h>
+#include <wlr/types/wlr_output_layout.h>
+#include <stdlib.h>
+#include <assert.h>
+
+struct wlr_output_layout *wlr_output_layout_init() {
+	struct wlr_output_layout *layout = calloc(1, sizeof(struct wlr_output_layout));
+	wl_list_init(&layout->outputs);
+	return layout;
+}
+
+void wlr_output_layout_destroy(struct wlr_output_layout *layout) {
+	if (!layout) {
+		return;
+	}
+
+	struct wlr_output_layout_output *_output, *temp = NULL;
+	wl_list_for_each_safe(_output, temp, &layout->outputs, link) {
+		wl_list_remove(&_output->link);
+		free(_output);
+	}
+
+	free(layout);
+}
+
+void wlr_output_layout_add(struct wlr_output_layout *layout,
+		struct wlr_output *output, int x, int y) {
+	struct wlr_output_layout_output *layout_output = calloc(1, sizeof(struct wlr_output_layout_output));
+	layout_output->output = output;
+	layout_output->x = x;
+	layout_output->y = y;
+	wl_list_insert(&layout->outputs, &layout_output->link);
+}
+
+static struct wlr_output_layout_output *wlr_output_layout_get(
+		struct wlr_output_layout *layout, struct wlr_output *reference) {
+	struct wlr_output_layout_output *ret = NULL;
+	struct wlr_output_layout_output *_output;
+	wl_list_for_each(_output, &layout->outputs, link) {
+		if (_output->output) {
+			ret = _output;
+		}
+	}
+
+	return ret;
+
+}
+
+struct wlr_output *wlr_output_layout_output_at(struct wlr_output_layout *layout,
+		double x, double y) {
+	struct wlr_output *ret = NULL;
+	struct wlr_output_layout_output *_output;
+	wl_list_for_each(_output, &layout->outputs, link) {
+		if (_output->output) {
+			int width, height;
+			wlr_output_effective_resolution(_output->output, &width, &height);
+			bool has_x = x >= _output->x && x <= _output->x + width;
+			bool has_y = y >= _output->y && y <= _output->y + height;
+			if (has_x && has_y) {
+				ret = _output->output;
+				break;
+			}
+		}
+	}
+
+	return ret;
+}
+
+void wlr_output_layout_move(struct wlr_output_layout *layout,
+		struct wlr_output *output, int x, int y) {
+	struct wlr_output_layout_output *layout_output =
+			wlr_output_layout_get(layout, output);
+	if (layout_output) {
+		layout_output->x = x;
+		layout_output->y = y;
+	}
+}
+
+void wlr_output_layout_remove(struct wlr_output_layout *layout,
+		struct wlr_output *output) {
+	struct wlr_output_layout_output *layout_output =
+			wlr_output_layout_get(layout, output);
+	if (layout_output) {
+		wl_list_remove(&layout_output->link);
+		free(layout_output);
+	}
+}
+
+void wlr_output_layout_output_coords(struct wlr_output_layout *layout,
+		struct wlr_output *reference, int *x, int *y) {
+	assert(layout && reference);
+	int src_x = *x;
+	int src_y = *y;
+
+	struct wlr_output_layout_output *_output;
+	wl_list_for_each(_output, &layout->outputs, link) {
+		if (_output->output == reference) {
+			*x = src_x - _output->x;
+			*y = src_y - _output->y;
+			return;
+		}
+	}
+}