weston/clients/cliptest.c
Loïc Molinari 39fee794b5 gl-renderer: Get rid of axis-aligned bbox check in simple clipper
Since both the surface rect and the transformed quad are axis-aligned
in the simple clipping path, non-zero area detection can more
efficiently be checked post-clipping by comparing opposite edges.

Signed-off-by: Loïc Molinari <loic.molinari@gmail.com>
2023-06-12 11:15:51 +00:00

695 lines
17 KiB
C

/*
* Copyright © 2012 Collabora, Ltd.
* Copyright © 2012 Rob Clark
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
/* cliptest:
* For debugging the rect_to_quad() and clip_quad() functions. An arbitrary
* quad (red) is transformed from global coordinate space to surface
* coordinate space and clipped to an axis-aligned rect (blue).
*
* controls:
* surface rect position: mouse left drag, keys: w a s d
* surface rect size: mouse right drag, keys: i j k l
* quad orientation: mouse wheel, keys: n m
* quad transform disable: key: r
*/
#include "config.h"
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <libgen.h>
#include <unistd.h>
#include <math.h>
#include <time.h>
#include <pixman.h>
#include <cairo.h>
#include <float.h>
#include <assert.h>
#include <errno.h>
#include <linux/input.h>
#include <wayland-client.h>
#include "libweston/matrix.h"
#include "libweston/vertex-clipping.h"
#include "shared/helpers.h"
#include "shared/xalloc.h"
#include "window.h"
typedef float GLfloat;
struct geometry {
pixman_box32_t surf;
pixman_box32_t quad;
float s; /* sin phi */
float c; /* cos phi */
float phi;
};
struct weston_surface {
};
struct weston_view {
struct weston_surface *surface;
struct {
int enabled;
struct weston_matrix matrix;
} transform;
struct geometry *geometry;
};
static void
weston_view_from_global_float(struct weston_view *view,
float x, float y, float *sx, float *sy)
{
struct geometry *g = view->geometry;
/* pure rotation around origin by sine and cosine */
*sx = g->c * x + g->s * y;
*sy = -g->s * x + g->c * y;
}
static struct weston_coord_surface
weston_coord_global_to_surface(struct weston_view *view, struct weston_coord_global g_pos)
{
float sx, sy;
struct weston_coord_surface pos;
weston_view_from_global_float(view, g_pos.c.x, g_pos.c.y, &sx, &sy);
pos.c = weston_coord(sx, sy);
return pos;
}
/* ---------------------- copied begins -----------------------*/
/* Keep this in sync with what is in gl-renderer.c! */
static void
rect_to_quad(pixman_box32_t *rect, struct weston_view *ev,
struct gl_quad *quad)
{
struct weston_coord_global rect_g[4] = {
{ .c = weston_coord(rect->x1, rect->y1) },
{ .c = weston_coord(rect->x2, rect->y1) },
{ .c = weston_coord(rect->x2, rect->y2) },
{ .c = weston_coord(rect->x1, rect->y2) },
};
struct weston_coord rect_s;
int i;
/* Transform rect to surface space. */
quad->vertices.n = 4;
for (i = 0; i < quad->vertices.n; i++) {
rect_s = weston_coord_global_to_surface(ev, rect_g[i]).c;
quad->vertices.pos[i].x = (float)rect_s.x;
quad->vertices.pos[i].y = (float)rect_s.y;
}
quad->axis_aligned = !ev->transform.enabled ||
(ev->transform.matrix.type < WESTON_MATRIX_TRANSFORM_ROTATE);
/* Find axis-aligned bounding box. */
if (!quad->axis_aligned) {
quad->bbox.x1 = quad->bbox.x2 = quad->vertices.pos[0].x;
quad->bbox.y1 = quad->bbox.y2 = quad->vertices.pos[0].y;
for (i = 1; i < quad->vertices.n; i++) {
quad->bbox.x1 = MIN(quad->bbox.x1,
quad->vertices.pos[i].x);
quad->bbox.x2 = MAX(quad->bbox.x2,
quad->vertices.pos[i].x);
quad->bbox.y1 = MIN(quad->bbox.y1,
quad->vertices.pos[i].y);
quad->bbox.y2 = MAX(quad->bbox.y2,
quad->vertices.pos[i].y);
}
}
}
/*
* Compute the boundary vertices of the intersection of an arbitrary
* quadrilateral 'quad' and the axis-aligned rectangle 'surf_rect'. The vertices
* are written to 'vertices', and the return value is the number of vertices.
* Vertices are produced in clockwise winding order. Guarantees to produce
* either zero vertices, or 3-8 vertices with non-zero polygon area.
*/
static int
clip_quad(struct gl_quad *quad, pixman_box32_t *surf_rect,
struct clip_vertex *vertices)
{
struct clip_context ctx = {
.clip.x1 = surf_rect->x1,
.clip.y1 = surf_rect->y1,
.clip.x2 = surf_rect->x2,
.clip.y2 = surf_rect->y2,
};
int n;
/* Simple case: quad edges are parallel to surface rect edges, there
* will be either four or zero edges. We just need to clip the quad to
* the surface rect bounds and test for non-zero area:
*/
if (quad->axis_aligned) {
clip_simple(&ctx, &quad->vertices, vertices);
if ((vertices[0].x != vertices[1].x) &&
(vertices[0].y != vertices[2].y))
return 4;
else
return 0;
}
/* Transformed case: first, simple bounding box check to discard early a
* quad that does not intersect with the rect:
*/
if ((quad->bbox.x1 >= ctx.clip.x2) || (quad->bbox.x2 <= ctx.clip.x1) ||
(quad->bbox.y1 >= ctx.clip.y2) || (quad->bbox.y2 <= ctx.clip.y1))
return 0;
/* Then, use a general polygon clipping algorithm to clip the quad with
* each side of the surface rect. The algorithm is Sutherland-Hodgman,
* as explained in
* http://www.codeguru.com/cpp/misc/misc/graphics/article.php/c8965/Polygon-Clipping.htm
* but without looking at any of that code.
*/
n = clip_transformed(&ctx, &quad->vertices, vertices);
if (n < 3)
return 0;
return n;
}
/* ---------------------- copied ends -----------------------*/
static void
geometry_set_phi(struct geometry *g, float phi)
{
g->phi = phi;
g->s = sin(phi);
g->c = cos(phi);
}
static void
geometry_init(struct geometry *g)
{
g->surf.x1 = -50;
g->surf.y1 = -50;
g->surf.x2 = -10;
g->surf.y2 = -10;
g->quad.x1 = -20;
g->quad.y1 = -20;
g->quad.x2 = 20;
g->quad.y2 = 20;
geometry_set_phi(g, 0.0);
}
struct ui_state {
uint32_t button;
int down;
int down_pos[2];
struct geometry geometry;
};
struct cliptest {
struct window *window;
struct widget *widget;
struct display *display;
int fullscreen;
struct ui_state ui;
struct geometry geometry;
struct weston_surface surface;
struct weston_view view;
};
static void
draw_polygon_closed(cairo_t *cr, struct clip_vertex *pos, int n)
{
int i;
cairo_move_to(cr, pos[0].x, pos[0].y);
for (i = 1; i < n; i++)
cairo_line_to(cr, pos[i].x, pos[i].y);
cairo_line_to(cr, pos[0].x, pos[0].y);
}
static void
draw_polygon_labels(cairo_t *cr, struct clip_vertex *pos, int n)
{
char str[16];
int i;
for (i = 0; i < n; i++) {
snprintf(str, 16, "%d", i);
cairo_move_to(cr, pos[i].x, pos[i].y);
cairo_show_text(cr, str);
}
}
static void
draw_coordinates(cairo_t *cr, double ox, double oy, struct clip_vertex *pos, int n)
{
char str[64];
int i;
cairo_font_extents_t ext;
cairo_font_extents(cr, &ext);
for (i = 0; i < n; i++) {
snprintf(str, 64, "%d: %14.9f, %14.9f", i, pos[i].x, pos[i].y);
cairo_move_to(cr, ox, oy + ext.height * (i + 1));
cairo_show_text(cr, str);
}
}
static void
draw_box(cairo_t *cr, pixman_box32_t *box, struct weston_view *view)
{
struct clip_vertex pos[4];
if (view) {
weston_view_from_global_float(view, box->x1, box->y1, &pos[0].x, &pos[0].y);
weston_view_from_global_float(view, box->x2, box->y1, &pos[1].x, &pos[1].y);
weston_view_from_global_float(view, box->x2, box->y2, &pos[2].x, &pos[2].y);
weston_view_from_global_float(view, box->x1, box->y2, &pos[3].x, &pos[3].y);
} else {
pos[0].x = box->x1; pos[0].y = box->y1;
pos[1].x = box->x2; pos[1].y = box->y1;
pos[2].x = box->x2; pos[2].y = box->y2;
pos[3].x = box->x1; pos[3].y = box->y2;
}
draw_polygon_closed(cr, pos, 4);
}
static void
draw_geometry(cairo_t *cr, struct weston_view *view,
struct clip_vertex *v, int n)
{
struct geometry *g = view->geometry;
float cx, cy;
draw_box(cr, &g->quad, view);
cairo_set_source_rgba(cr, 1.0, 0.0, 0.0, 0.4);
cairo_fill(cr);
weston_view_from_global_float(view, g->quad.x1 - 4, g->quad.y1 - 4, &cx, &cy);
cairo_arc(cr, cx, cy, 1.5, 0.0, 2.0 * M_PI);
if (view->transform.enabled == 0)
cairo_set_source_rgba(cr, 1.0, 0.0, 0.0, 0.8);
cairo_fill(cr);
draw_box(cr, &g->surf, NULL);
cairo_set_source_rgba(cr, 0.0, 0.0, 1.0, 0.4);
cairo_fill(cr);
if (n) {
draw_polygon_closed(cr, v, n);
cairo_set_source_rgb(cr, 0.0, 1.0, 0.0);
cairo_stroke(cr);
cairo_set_source_rgba(cr, 0.0, 1.0, 0.0, 0.5);
draw_polygon_labels(cr, v, n);
}
}
static void
redraw_handler(struct widget *widget, void *data)
{
struct cliptest *cliptest = data;
struct geometry *g = cliptest->view.geometry;
struct rectangle allocation;
cairo_t *cr;
cairo_surface_t *surface;
struct gl_quad quad;
struct clip_vertex v[8];
int n;
rect_to_quad(&g->quad, &cliptest->view, &quad);
n = clip_quad(&quad, &g->surf, v);
widget_get_allocation(cliptest->widget, &allocation);
surface = window_get_surface(cliptest->window);
cr = cairo_create(surface);
widget_get_allocation(cliptest->widget, &allocation);
cairo_rectangle(cr, allocation.x, allocation.y,
allocation.width, allocation.height);
cairo_clip(cr);
cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE);
cairo_set_source_rgba(cr, 0, 0, 0, 1);
cairo_paint(cr);
cairo_translate(cr, allocation.x, allocation.y);
cairo_set_line_width(cr, 1.0);
cairo_move_to(cr, allocation.width / 2.0, 0.0);
cairo_line_to(cr, allocation.width / 2.0, allocation.height);
cairo_move_to(cr, 0.0, allocation.height / 2.0);
cairo_line_to(cr, allocation.width, allocation.height / 2.0);
cairo_set_source_rgba(cr, 0.5, 0.5, 0.5, 1.0);
cairo_stroke(cr);
cairo_set_operator(cr, CAIRO_OPERATOR_OVER);
cairo_push_group(cr);
cairo_translate(cr, allocation.width / 2.0,
allocation.height / 2.0);
cairo_scale(cr, 4.0, 4.0);
cairo_set_line_width(cr, 0.5);
cairo_set_line_join(cr, CAIRO_LINE_JOIN_BEVEL);
cairo_select_font_face(cr, "sans-serif", CAIRO_FONT_SLANT_NORMAL,
CAIRO_FONT_WEIGHT_BOLD);
cairo_set_font_size(cr, 5.0);
draw_geometry(cr, &cliptest->view, v, n);
cairo_pop_group_to_source(cr);
cairo_paint(cr);
cairo_set_source_rgba(cr, 0.0, 1.0, 0.0, 1.0);
cairo_select_font_face(cr, "monospace", CAIRO_FONT_SLANT_NORMAL,
CAIRO_FONT_WEIGHT_NORMAL);
cairo_set_font_size(cr, 12.0);
draw_coordinates(cr, 10.0, 10.0, v, n);
cairo_destroy(cr);
cairo_surface_destroy(surface);
}
static int
motion_handler(struct widget *widget, struct input *input,
uint32_t time, float x, float y, void *data)
{
struct cliptest *cliptest = data;
struct ui_state *ui = &cliptest->ui;
struct geometry *ref = &ui->geometry;
struct geometry *geom = &cliptest->geometry;
float dx, dy;
if (!ui->down)
return CURSOR_LEFT_PTR;
dx = (x - ui->down_pos[0]) * 0.25;
dy = (y - ui->down_pos[1]) * 0.25;
switch (ui->button) {
case BTN_LEFT:
geom->surf.x1 = ref->surf.x1 + dx;
geom->surf.y1 = ref->surf.y1 + dy;
/* fall through */
case BTN_RIGHT:
geom->surf.x2 = ref->surf.x2 + dx;
geom->surf.y2 = ref->surf.y2 + dy;
break;
default:
return CURSOR_LEFT_PTR;
}
widget_schedule_redraw(cliptest->widget);
return CURSOR_BLANK;
}
static void
button_handler(struct widget *widget, struct input *input,
uint32_t time, uint32_t button,
enum wl_pointer_button_state state, void *data)
{
struct cliptest *cliptest = data;
struct ui_state *ui = &cliptest->ui;
ui->button = button;
if (state == WL_POINTER_BUTTON_STATE_PRESSED) {
ui->down = 1;
input_get_position(input, &ui->down_pos[0], &ui->down_pos[1]);
} else {
ui->down = 0;
ui->geometry = cliptest->geometry;
}
}
static void
axis_handler(struct widget *widget, struct input *input, uint32_t time,
uint32_t axis, wl_fixed_t value, void *data)
{
struct cliptest *cliptest = data;
struct geometry *geom = &cliptest->geometry;
if (axis != WL_POINTER_AXIS_VERTICAL_SCROLL)
return;
geometry_set_phi(geom, geom->phi +
(M_PI / 12.0) * wl_fixed_to_double(value));
cliptest->view.transform.enabled = 1;
cliptest->view.transform.matrix.type = WESTON_MATRIX_TRANSFORM_ROTATE;
widget_schedule_redraw(cliptest->widget);
}
static void
key_handler(struct window *window, struct input *input, uint32_t time,
uint32_t key, uint32_t sym,
enum wl_keyboard_key_state state, void *data)
{
struct cliptest *cliptest = data;
struct geometry *g = &cliptest->geometry;
if (state == WL_KEYBOARD_KEY_STATE_RELEASED)
return;
switch (sym) {
case XKB_KEY_Escape:
display_exit(cliptest->display);
return;
case XKB_KEY_w:
g->surf.y1 -= 1;
g->surf.y2 -= 1;
break;
case XKB_KEY_a:
g->surf.x1 -= 1;
g->surf.x2 -= 1;
break;
case XKB_KEY_s:
g->surf.y1 += 1;
g->surf.y2 += 1;
break;
case XKB_KEY_d:
g->surf.x1 += 1;
g->surf.x2 += 1;
break;
case XKB_KEY_i:
g->surf.y2 -= 1;
break;
case XKB_KEY_j:
g->surf.x2 -= 1;
break;
case XKB_KEY_k:
g->surf.y2 += 1;
break;
case XKB_KEY_l:
g->surf.x2 += 1;
break;
case XKB_KEY_n:
geometry_set_phi(g, g->phi + (M_PI / 24.0));
cliptest->view.transform.enabled = 1;
cliptest->view.transform.matrix.type =
WESTON_MATRIX_TRANSFORM_ROTATE;
break;
case XKB_KEY_m:
geometry_set_phi(g, g->phi - (M_PI / 24.0));
cliptest->view.transform.enabled = 1;
cliptest->view.transform.matrix.type =
WESTON_MATRIX_TRANSFORM_ROTATE;
break;
case XKB_KEY_r:
geometry_set_phi(g, 0.0);
cliptest->view.transform.enabled = 0;
cliptest->view.transform.matrix.type = 0;
break;
default:
return;
}
widget_schedule_redraw(cliptest->widget);
}
static void
keyboard_focus_handler(struct window *window,
struct input *device, void *data)
{
struct cliptest *cliptest = data;
window_schedule_redraw(cliptest->window);
}
static void
fullscreen_handler(struct window *window, void *data)
{
struct cliptest *cliptest = data;
cliptest->fullscreen ^= 1;
window_set_fullscreen(window, cliptest->fullscreen);
}
static struct cliptest *
cliptest_create(struct display *display)
{
struct cliptest *cliptest;
cliptest = xzalloc(sizeof *cliptest);
cliptest->view.surface = &cliptest->surface;
cliptest->view.geometry = &cliptest->geometry;
cliptest->view.transform.enabled = 0;
cliptest->view.transform.matrix.type = 0;
geometry_init(&cliptest->geometry);
geometry_init(&cliptest->ui.geometry);
cliptest->window = window_create(display);
cliptest->widget = window_frame_create(cliptest->window, cliptest);
window_set_title(cliptest->window, "cliptest");
window_set_appid(cliptest->window, "org.freedesktop.weston.cliptest");
cliptest->display = display;
window_set_user_data(cliptest->window, cliptest);
widget_set_redraw_handler(cliptest->widget, redraw_handler);
widget_set_button_handler(cliptest->widget, button_handler);
widget_set_motion_handler(cliptest->widget, motion_handler);
widget_set_axis_handler(cliptest->widget, axis_handler);
window_set_keyboard_focus_handler(cliptest->window,
keyboard_focus_handler);
window_set_key_handler(cliptest->window, key_handler);
window_set_fullscreen_handler(cliptest->window, fullscreen_handler);
/* set minimum size */
widget_schedule_resize(cliptest->widget, 200, 100);
/* set current size */
widget_schedule_resize(cliptest->widget, 500, 400);
return cliptest;
}
static struct timespec begin_time;
static void
reset_timer(void)
{
clock_gettime(CLOCK_MONOTONIC, &begin_time);
}
static double
read_timer(void)
{
struct timespec t;
clock_gettime(CLOCK_MONOTONIC, &t);
return (double)(t.tv_sec - begin_time.tv_sec) +
1e-9 * (t.tv_nsec - begin_time.tv_nsec);
}
static int
benchmark(void)
{
struct weston_surface surface;
struct weston_view view;
struct geometry geom;
struct gl_quad quad;
struct clip_vertex v[8];
int i;
double t;
const int N = 1000000;
geom.surf.x1 = -19;
geom.surf.y1 = -19;
geom.surf.x2 = 19;
geom.surf.y2 = 19;
geom.quad.x1 = -20;
geom.quad.y1 = -20;
geom.quad.x2 = 20;
geom.quad.y2 = 20;
geometry_set_phi(&geom, 0.0);
view.surface = &surface;
view.transform.enabled = 1;
view.transform.matrix.type = WESTON_MATRIX_TRANSFORM_ROTATE;
view.geometry = &geom;
reset_timer();
for (i = 0; i < N; i++) {
geometry_set_phi(&geom, (float)i / 360.0f);
rect_to_quad(&geom.quad, &view, &quad);
clip_quad(&quad, &geom.surf, v);
}
t = read_timer();
printf("%d calls took %g s, average %g us/call\n", N, t, t / N * 1e6);
return 0;
}
static void
cliptest_destroy(struct cliptest *cliptest)
{
widget_destroy(cliptest->widget);
window_destroy(cliptest->window);
free(cliptest);
}
int
main(int argc, char *argv[])
{
struct display *d;
struct cliptest *cliptest;
if (argc > 1) {
if (argc == 2 && !strcmp(argv[1], "-b"))
return benchmark();
printf("Usage: %s [OPTIONS]\n -b run benchmark\n", argv[0]);
return 1;
}
d = display_create(&argc, argv);
if (d == NULL) {
fprintf(stderr, "failed to create display: %s\n",
strerror(errno));
return -1;
}
cliptest = cliptest_create(d);
display_run(d);
cliptest_destroy(cliptest);
display_destroy(d);
return 0;
}