cairo-pango-gles2 bug report (start reading surface.c -> main; the headers are from wayland weston and probably not relevant)

Makefile

all:
        gcc surface.c -o surface ${CFLAGS} ${LDFLAGS} $(shell pkg-config --libs --cflags cairo wayland-client wayland-server wayland-egl pango pangocairo) -lEGL -Wall -Wextra

platform.h

/*
 * Copyright © 2015 Collabora, Ltd.
 *
 * 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.
 */

#ifndef WESTON_PLATFORM_H
#define WESTON_PLATFORM_H

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

#ifdef ENABLE_EGL
#include <wayland-egl.h>
#include <EGL/egl.h>
#include <EGL/eglext.h>

#include "weston-egl-ext.h"
#endif

#ifdef  __cplusplus
extern "C" {
#endif

#ifdef ENABLE_EGL

static bool
weston_check_egl_extension(const char *extensions, const char *extension)
{
	size_t extlen = strlen(extension);
	const char *end = extensions + strlen(extensions);

	while (extensions < end) {
		size_t n = 0;

		/* Skip whitespaces, if any */
		if (*extensions == ' ') {
			extensions++;
			continue;
		}

		n = strcspn(extensions, " ");

		/* Compare strings */
		if (n == extlen && strncmp(extension, extensions, n) == 0)
			return true; /* Found */

		extensions += n;
	}

	/* Not found */
	return false;
}

static inline void *
weston_platform_get_egl_proc_address(const char *address)
{
	const char *extensions = eglQueryString(EGL_NO_DISPLAY, EGL_EXTENSIONS);

	if (extensions &&
	    (weston_check_egl_extension(extensions, "EGL_EXT_platform_wayland") ||
	     weston_check_egl_extension(extensions, "EGL_KHR_platform_wayland"))) {
		return (void *) eglGetProcAddress(address);
	}

	return NULL;
}

static inline EGLDisplay
weston_platform_get_egl_display(EGLenum platform, void *native_display,
				const EGLint *attrib_list)
{
	static PFNEGLGETPLATFORMDISPLAYEXTPROC get_platform_display = NULL;

	if (!get_platform_display) {
		get_platform_display = (PFNEGLGETPLATFORMDISPLAYEXTPROC)
            weston_platform_get_egl_proc_address(
                "eglGetPlatformDisplayEXT");
	}

	if (get_platform_display)
		return get_platform_display(platform,
					    native_display, attrib_list);

	return eglGetDisplay((EGLNativeDisplayType) native_display);
}

static inline EGLSurface
weston_platform_create_egl_surface(EGLDisplay dpy, EGLConfig config,
				   void *native_window,
				   const EGLint *attrib_list)
{
	static PFNEGLCREATEPLATFORMWINDOWSURFACEEXTPROC
		create_platform_window = NULL;

	if (!create_platform_window) {
		create_platform_window = (PFNEGLCREATEPLATFORMWINDOWSURFACEEXTPROC)
            weston_platform_get_egl_proc_address(
                "eglCreatePlatformWindowSurfaceEXT");
	}

	if (create_platform_window)
		return create_platform_window(dpy, config,
					      native_window,
					      attrib_list);

	return eglCreateWindowSurface(dpy, config,
				      (EGLNativeWindowType) native_window,
				      attrib_list);
}

static inline EGLBoolean
weston_platform_destroy_egl_surface(EGLDisplay display,
				    EGLSurface surface)
{
	return eglDestroySurface(display, surface);
}

#else /* ENABLE_EGL */

static inline void *
weston_platform_get_egl_display(void *platform, void *native_display,
				const int *attrib_list)
{
	return NULL;
}

static inline void *
weston_platform_create_egl_surface(void *dpy, void *config,
				   void *native_window,
				   const int *attrib_list)
{
	return NULL;
}

static inline unsigned int
weston_platform_destroy_egl_surface(void *display,
				    void *surface)
{
	return 1;
}
#endif /* ENABLE_EGL */

#ifdef  __cplusplus
}
#endif

#endif /* WESTON_PLATFORM_H */

surface.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <stdint.h>
#include <stdbool.h>
#include <cairo/cairo.h>

#include <time.h>
#include <wayland-client.h>
#include <wayland-server.h>
#include <wayland-client-protocol.h>
#include <wayland-egl.h>
#include <EGL/egl.h>

#ifndef USE_PANGO
# define USE_PANGO 0
#endif

#include <cairo/cairo-gl.h>

#if USE_PANGO
#include <pango/pango.h>
#include <pango/pangocairo.h>
#endif

// Define needed to make platform.h actually define weston_platform_create_egl_surface()
#define ENABLE_EGL 1
#include "platform.h"

typedef struct Surface {
    struct wl_display *display;
    struct wl_compositor *compositor;
    struct wl_surface *surface;
    struct wl_egl_window *egl_window;
    struct wl_region *region;
    struct wl_shell *shell;
    struct wl_shell_surface *shell_surface;

    EGLDisplay egl_display;
    EGLConfig egl_conf;
    EGLSurface egl_surface;
    EGLContext egl_context;

    cairo_surface_t *cairo_surface;
    cairo_device_t *cairo_device;

    cairo_t *ctx;
} Surface;

static const char *create_window(Surface *srf, uint32_t width, uint32_t height) {
    printf("creating window with width=%d and height=%d\n", width, height);
    srf->egl_window = wl_egl_window_create(srf->surface, width, height);
    if(srf->egl_window == EGL_NO_SURFACE) {
	    return "can't create egl window";
    }

	printf("created egl window\n");

	srf->egl_surface = weston_platform_create_egl_surface(srf->egl_display, srf->egl_conf, srf->egl_window, NULL);
    srf->cairo_surface = cairo_gl_surface_create_for_egl(srf->cairo_device, srf->egl_surface, width, height);

    if(srf->cairo_surface == NULL) {
        return "can't create Cairo surface";
    }

    srf->ctx = cairo_create(srf->cairo_surface);
    if(cairo_status(srf->ctx) != CAIRO_STATUS_SUCCESS) {
	    return "cairo error on create";
    }

    return NULL;
}

static const char *init_egl(Surface *srf) {
    EGLint major, minor, count, n, size;
    EGLConfig *configs;

    EGLint config_attribs[] = {
        EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
        EGL_RED_SIZE, 8,
        EGL_GREEN_SIZE, 8,
        EGL_BLUE_SIZE, 8,
        EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
        EGL_NONE
    };

    static const EGLint context_attribs[] = {
        EGL_CONTEXT_CLIENT_VERSION, 2,
        EGL_NONE
    };

    int i;

    srf->egl_display = eglGetDisplay((EGLNativeDisplayType) srf->display);
    if(srf->egl_display == EGL_NO_DISPLAY) {
        return "can't create egl display";
    }

    if(eglInitialize(srf->egl_display, &major, &minor) != EGL_TRUE) {
        return "can't initialise egl display";
    }

    fprintf(stderr, "EGL major: %d, minor %d\n", major, minor);

    if(!eglBindAPI(EGL_OPENGL_API)) {
	    return "failed to bind EGL client API";
    }

    eglGetConfigs(srf->egl_display, NULL, 0, &count);
    configs = calloc(count, sizeof *configs);
    eglChooseConfig(srf->egl_display, config_attribs, configs, count, &n);

    for(i = 0; i < n; i++) {
        eglGetConfigAttrib(srf->egl_display, configs[i], EGL_BUFFER_SIZE, &size);
        printf("buffer size for config %d is %d\n", i, size);
        eglGetConfigAttrib(srf->egl_display, configs[i], EGL_RED_SIZE, &size);
        printf("red size for config %d is %d\n", i, size);

        // just choose the first one
        srf->egl_conf = configs[i];
        break;
    }

    srf->egl_context = eglCreateContext(srf->egl_display, srf->egl_conf, EGL_NO_CONTEXT, context_attribs);
    if(srf->egl_context == NULL) {
	    return "can't create context";
    }

    srf->cairo_device = cairo_egl_device_create(srf->egl_display, srf->egl_context);
    if(cairo_device_status(srf->cairo_device) != CAIRO_STATUS_SUCCESS) {
        return "failed to get cairo EGL device";
    }

    return NULL;
}

/////////////////

static void global_registry_handler(void *data, struct wl_registry *registry, uint32_t id, const char *interface, uint32_t version) {
    (void) version;

    Surface *srf = (Surface *)data;

    if(strcmp(interface, "wl_compositor") == 0) {
        srf->compositor = wl_registry_bind(registry, id, &wl_compositor_interface, 1);
    } else if (strcmp(interface, "wl_shell") == 0) {
	    srf->shell = wl_registry_bind(registry, id, &wl_shell_interface, 1);
    }
}

static void global_registry_remover(void *data, struct wl_registry *registry, uint32_t id) {
    (void) data;
    (void) registry;
    (void) id;
}

static const struct wl_registry_listener registry_listener = {
    global_registry_handler,
    global_registry_remover
};


static const char * get_server_references(Surface *srf) {
    srf->display = wl_display_connect(NULL);
    if(srf->display == NULL) {
        return "can't connect to display";
    }

    struct wl_registry *registry = wl_display_get_registry(srf->display);
    wl_registry_add_listener(registry, &registry_listener, srf);

    wl_display_dispatch(srf->display);
    wl_display_roundtrip(srf->display);

    if(srf->compositor == NULL || srf->shell == NULL) {
        return "can't find compositor or shell";
    }

    return NULL;
}

/////////////

static Surface * ui_surface_create(uint32_t width, uint32_t height, const char **out_err) {
    Surface *srf = calloc(1, sizeof(Surface));

    const char *err = get_server_references(srf);
    if(err != NULL) {
        *out_err = err;
        free(srf);
        return NULL;
    }

    srf->surface = wl_compositor_create_surface(srf->compositor);
    if(srf->surface == NULL) {
        *out_err = "can't create surface";
        free(srf);
        return NULL;
    }

    srf->shell_surface = wl_shell_get_shell_surface(srf->shell, srf->surface);
    wl_shell_surface_set_toplevel(srf->shell_surface);

    if((err = init_egl(srf)) != NULL) {
        *out_err = err;
        free(srf);
        return NULL;
    }

    if((err = create_window(srf, width, height)) != NULL) {
        *out_err = err;
        free(srf);
        return NULL;
    }

    return srf;
}

static void ui_surface_free(void *vsrf) {
    Surface *srf = vsrf;
    wl_display_disconnect(srf->display);
    free(srf);
}

static cairo_t *ui_surface_get_context(void *vsrf) {
    Surface *srf = vsrf;
    return srf->ctx;
}

static void ui_surface_swap_buffers(void *vsrf) {
    Surface *srf = vsrf;
    cairo_gl_surface_swapbuffers(srf->cairo_surface);
}

int main(void) {
    const char *err = NULL;
    const int width = 340;
    const int height = 480;

    Surface *srf = ui_surface_create(width, height, &err);

    if(srf == NULL) {
        fprintf(stderr, "failed to create surface: %s\n", err);
        return EXIT_FAILURE;
    }

    cairo_t * ctx = ui_surface_get_context(srf);

#if USE_PANGO
    PangoFontDescription *desc = pango_font_description_from_string("Sans 20");
#else
    cairo_select_font_face(ctx, "Sans", CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_NORMAL);
    cairo_set_font_size(ctx, 20);
#endif

    float value = 0;
    float direction = +0.01;

    while(1) {
        cairo_set_source_rgb(ctx, 1-value, 1-value, 1-value);
        cairo_paint(ctx);

        cairo_set_source_rgb(ctx, value, value, value);

        if(cairo_status(ctx) != CAIRO_STATUS_SUCCESS) {
            printf("drawing failed before text: %s\n", cairo_status_to_string(cairo_status(ctx)));
            return EXIT_FAILURE;
        }

#if USE_PANGO
        PangoLayout *lay = pango_cairo_create_layout(ctx);
        pango_layout_set_text(lay, "Hello from Pango!", -1);
        pango_layout_set_font_description(lay, desc);

        int tw = 0, th = 0;
        pango_layout_get_size(lay, &tw, &th);
        tw /= PANGO_SCALE;
        th /= PANGO_SCALE;
        cairo_move_to(ctx, width/2-tw/2, height/2-th/2);
        pango_cairo_show_layout(ctx, lay);
#else
        cairo_text_extents_t extents;
        cairo_text_extents(ctx, "Hello from Cairo!", &extents);
        cairo_move_to(ctx, width/2-extents.width/2, height/2-extents.height/2);
        cairo_show_text(ctx, "Hello from Cairo!");
#endif
	    
        // It fails here (both for cairo_show_text and pango):
        if(cairo_status(ctx) != CAIRO_STATUS_SUCCESS) {
            printf("drawing text failed: %s\n", cairo_status_to_string(cairo_status(ctx)));
            return EXIT_FAILURE;
        }

        ui_surface_swap_buffers(srf);

        value += direction;

        if(value > 1.0) {
            direction *= -1;
        }

        if(value < 0.0) {
            direction *= -1;
        }
    }

#if USE_PANGO
    pango_font_description_free(desc);
#endif

    ui_surface_free(srf);
    return EXIT_SUCCESS;
}

weston-egl-ext.h

/**************************************************************************
 *
 * Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.
 * All Rights Reserved.
 *
 * 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, sub license, 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.
 *
 **************************************************************************/

/* Extensions used by Weston, copied from Mesa's eglmesaext.h, */

#ifndef WESTON_EGL_EXT_H
#define WESTON_EGL_EXT_H

#ifndef EGL_WL_bind_wayland_display
#define EGL_WL_bind_wayland_display 1

#define EGL_WAYLAND_BUFFER_WL		0x31D5 /* eglCreateImageKHR target */
#define EGL_WAYLAND_PLANE_WL		0x31D6 /* eglCreateImageKHR target */

#define EGL_TEXTURE_Y_U_V_WL            0x31D7
#define EGL_TEXTURE_Y_UV_WL             0x31D8
#define EGL_TEXTURE_Y_XUXV_WL           0x31D9
#define EGL_TEXTURE_EXTERNAL_WL         0x31DA

struct wl_display;
struct wl_buffer;
#ifdef EGL_EGLEXT_PROTOTYPES
EGLAPI EGLBoolean EGLAPIENTRY eglBindWaylandDisplayWL(EGLDisplay dpy, struct wl_display *display);
EGLAPI EGLBoolean EGLAPIENTRY eglUnbindWaylandDisplayWL(EGLDisplay dpy, struct wl_display *display);
EGLAPI EGLBoolean EGLAPIENTRY eglQueryWaylandBufferWL(EGLDisplay dpy, struct wl_buffer *buffer, EGLint attribute, EGLint *value);
#endif
typedef EGLBoolean (EGLAPIENTRYP PFNEGLBINDWAYLANDDISPLAYWL) (EGLDisplay dpy, struct wl_display *display);
typedef EGLBoolean (EGLAPIENTRYP PFNEGLUNBINDWAYLANDDISPLAYWL) (EGLDisplay dpy, struct wl_display *display);
typedef EGLBoolean (EGLAPIENTRYP PFNEGLQUERYWAYLANDBUFFERWL) (EGLDisplay dpy, struct wl_buffer *buffer, EGLint attribute, EGLint *value);

#endif

#ifndef EGL_TEXTURE_EXTERNAL_WL
#define EGL_TEXTURE_EXTERNAL_WL         0x31DA
#endif

#endif