path: root/examples/pugl_cairo_demo.c

/*
  Copyright 2012-2020 David Robillard <d@drobilla.net>

  Permission to use, copy, modify, and/or distribute this software for any
  purpose with or without fee is hereby granted, provided that the above
  copyright notice and this permission notice appear in all copies.

  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/

/**
   @file pugl_cairo_demo.c
   @brief An example of drawing with Cairo.
*/

#include "demo_utils.h"
#include "test/test_utils.h"

#include "pugl/pugl.h"
#include "pugl/pugl_cairo.h"

#include <cairo.h>

#include <math.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>

typedef struct {
	PuglTestOptions opts;
	PuglWorld*      world;
	unsigned        framesDrawn;
	int             quit;
	bool            entered;
	bool            mouseDown;
} PuglTestApp;

typedef struct {
	int         x;
	int         y;
	int         w;
	int         h;
	const char* label;
} Button;

static const Button buttons[] = {{128, 128, 64, 64, "1"},
                                 {384, 128, 64, 64, "2"},
                                 {128, 384, 64, 64, "3"},
                                 {384, 384, 64, 64, "4"},
                                 {0, 0, 0, 0, NULL}};

static void
roundedBox(cairo_t* cr, double x, double y, double w, double h)
{
	static const double radius  = 10;
	static const double degrees = 3.14159265 / 180.0;

	cairo_new_sub_path(cr);
	cairo_arc(cr,
	          x + w - radius,
	          y + radius,
	          radius, -90 * degrees, 0 * degrees);
	cairo_arc(cr,
	          x + w - radius, y + h - radius,
	          radius, 0 * degrees, 90 * degrees);
	cairo_arc(cr,
	          x + radius, y + h - radius,
	          radius, 90 * degrees, 180 * degrees);
	cairo_arc(cr,
	          x + radius, y + radius,
	          radius, 180 * degrees, 270 * degrees);
	cairo_close_path(cr);
}

static void
buttonDraw(PuglTestApp* app, cairo_t* cr, const Button* but, const double time)
{
	cairo_save(cr);
	cairo_translate(cr, but->x, but->y);
	cairo_rotate(cr, sin(time) * 3.141592);

	// Draw base
	if (app->mouseDown) {
		cairo_set_source_rgba(cr, 0.4, 0.9, 0.1, 1);
	} else {
		cairo_set_source_rgba(cr, 0.3, 0.5, 0.1, 1);
	}
	roundedBox(cr, 0, 0, but->w, but->h);
	cairo_fill_preserve(cr);

	// Draw border
	cairo_set_source_rgba(cr, 0.4, 0.9, 0.1, 1);
	cairo_set_line_width(cr, 4.0);
	cairo_stroke(cr);

	// Draw label
	cairo_text_extents_t extents;
	cairo_set_font_size(cr, 32.0);
	cairo_text_extents(cr, but->label, &extents);
	cairo_move_to(cr,
	              (but->w / 2.0) - extents.width / 2,
	              (but->h / 2.0) + extents.height / 2);
	cairo_set_source_rgba(cr, 0, 0, 0, 1);
	cairo_show_text(cr, but->label);

	cairo_restore(cr);
}

static void
postButtonRedisplay(PuglView* view)
{
	const PuglRect frame  = puglGetFrame(view);
	const double   width  = frame.width;
	const double   height = frame.height;
	const double   scaleX = (width - (512 / width)) / 512.0;
	const double   scaleY = (height - (512 / height)) / 512.0;

	for (const Button* b = buttons; b->label; ++b) {
		const double   span = sqrt(b->w * b->w + b->h * b->h);
		const PuglRect rect = {(b->x - span) * scaleX,
		                       (b->y - span) * scaleY,
		                       span * 2.0 * scaleX,
		                       span * 2.0 * scaleY};

		puglPostRedisplayRect(view, rect);
	}
}

static void
onDisplay(PuglTestApp* app, PuglView* view, const PuglEventExpose* event)
{
	cairo_t* cr = (cairo_t*)puglGetContext(view);

	cairo_rectangle(cr, event->x, event->y, event->width, event->height);
	cairo_clip_preserve(cr);

	// Draw background
	const PuglRect frame  = puglGetFrame(view);
	const double   width  = frame.width;
	const double   height = frame.height;
	if (app->entered) {
		cairo_set_source_rgb(cr, 0.1, 0.1, 0.1);
	} else {
		cairo_set_source_rgb(cr, 0, 0, 0);
	}
	cairo_fill(cr);

	// Scale to view size
	const double scaleX = (width - (512 / width)) / 512.0;
	const double scaleY = (height - (512 / height)) / 512.0;
	cairo_scale(cr, scaleX, scaleY);

	// Draw button
	for (const Button* b = buttons; b->label; ++b) {
		buttonDraw(app,
		           cr,
		           b,
		           app->opts.continuous ? puglGetTime(app->world) : 0.0);
	}

	++app->framesDrawn;
}

static void
onClose(PuglView* view)
{
	PuglTestApp* app = (PuglTestApp*)puglGetHandle(view);

	app->quit = 1;
}

static PuglStatus
onEvent(PuglView* view, const PuglEvent* event)
{
	PuglTestApp* app = (PuglTestApp*)puglGetHandle(view);

	printEvent(event, "Event: ", app->opts.verbose);

	switch (event->type) {
	case PUGL_KEY_PRESS:
		if (event->key.key == 'q' || event->key.key == PUGL_KEY_ESCAPE) {
			app->quit = 1;
		}
		break;
	case PUGL_BUTTON_PRESS:
		app->mouseDown = true;
		postButtonRedisplay(view);
		break;
	case PUGL_BUTTON_RELEASE:
		app->mouseDown = false;
		postButtonRedisplay(view);
		break;
	case PUGL_POINTER_IN:
		app->entered = true;
		puglPostRedisplay(view);
		break;
	case PUGL_POINTER_OUT:
		app->entered = false;
		puglPostRedisplay(view);
		break;
	case PUGL_UPDATE:
		if (app->opts.continuous) {
			puglPostRedisplay(view);
		}
		break;
	case PUGL_EXPOSE:
		onDisplay(app, view, &event->expose);
		break;
	case PUGL_CLOSE:
		onClose(view);
		break;
	default: break;
	}

	return PUGL_SUCCESS;
}

int
main(int argc, char** argv)
{
	PuglTestApp app;
	memset(&app, 0, sizeof(app));

	app.opts = puglParseTestOptions(&argc, &argv);
	if (app.opts.help) {
		puglPrintTestUsage("pugl_test", "");
		return 1;
	}

	app.world = puglNewWorld(PUGL_PROGRAM, 0);
	puglSetClassName(app.world, "PuglCairoTest");

	PuglView* view = puglNewView(app.world);

	puglSetWindowTitle(view, "Pugl Cairo Demo");
	puglSetDefaultSize(view, 512, 512);
	puglSetMinSize(view, 256, 256);
	puglSetViewHint(view, PUGL_RESIZABLE, app.opts.resizable);
	puglSetHandle(view, &app);
	puglSetBackend(view, puglCairoBackend());
	puglSetViewHint(view, PUGL_IGNORE_KEY_REPEAT, app.opts.ignoreKeyRepeat);
	puglSetEventFunc(view, onEvent);

	PuglStatus st = puglRealize(view);
	if (st) {
		return logError("Failed to create window (%s)\n", puglStrerror(st));
	}

	puglShowWindow(view);

	PuglFpsPrinter fpsPrinter = { puglGetTime(app.world) };
	const double   timeout    = app.opts.continuous ? (1 / 60.0) : -1.0;
	while (!app.quit) {
		puglUpdate(app.world, timeout);

		if (app.opts.continuous) {
			puglPrintFps(app.world, &fpsPrinter, &app.framesDrawn);
		}
	}

	puglFreeView(view);
	puglFreeWorld(app.world);
	return 0;
}