Gameover Screen
Simple Astroids clone
Published
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Lastly, we detect when the player sprite comes in contact with an astroid. If it does, we stop the game loop and draw a gameover sprite on top of the screen prompting the user to press ‘r’ to restart. If the ‘r’ key is pressed in this state we execute a function to reset all of the values in the game and allow the game loop to pass through.
main.c
#include <epoxy/gl.h>
#include <epoxy/glx.h>
#include <gtk/gtk.h>
#include <math.h>
#include <stdlib.h>
#include "DashGL/dashgl.h"
static void on_realize(GtkGLArea *area);
static void on_render(GtkGLArea *area, GdkGLContext *context);
static gboolean on_idle(gpointer data);
static gboolean on_keydown(GtkWidget *widget, GdkEventKey *event);
static gboolean on_keyup(GtkWidget *widget, GdkEventKey *event);
static void reset_game();
#define NUM_BULLETS 10
#define WIDTH 640.0f
#define HEIGHT 480.0f
#define NUM_ROCKS 16
GLuint program;
GLuint vao;
GLint attribute_texcoord, attribute_coord2d;
GLint uniform_mytexture, uniform_mvp;
struct bullet {
vec3 pos;
GLfloat rot;
gboolean active;
int ticks;
};
struct {
GLuint vbo[2];
GLuint tex[2];
vec3 pos;
mat4 mvp;
gboolean left;
gboolean right;
gboolean up;
gboolean space;
GLfloat rot;
GLfloat dx, dy, max;
float bullet_speed;
int num_ticks;
struct bullet bullets[NUM_BULLETS];
} player;
struct rock {
vec3 pos;
float rot;
float dx, dy;
int size;
gboolean active;
};
struct {
GLuint vbo;
GLuint tex;
mat4 mvp;
float radius;
struct rock rocks[NUM_ROCKS];
} astroid;
struct {
GLuint vbo;
GLuint tex;
mat4 mvp;
gboolean off;
} gameover;
int main(int argc, char *argv[]) {
GtkWidget *window;
GtkWidget *glArea;
gtk_init(&argc, &argv);
// Initialize Window
window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
gtk_window_set_title(GTK_WINDOW(window), "Astroids Tutorial");
gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
gtk_window_set_default_size(GTK_WINDOW(window), 640, 480);
gtk_window_set_type_hint(GTK_WINDOW(window), GDK_WINDOW_TYPE_HINT_UTILITY);
g_signal_connect(window, "destroy", G_CALLBACK(gtk_main_quit), NULL);
g_signal_connect(window, "key-press-event", G_CALLBACK(on_keydown), NULL);
g_signal_connect(window, "key-release-event", G_CALLBACK(on_keyup), NULL);
// Initialize GTK GL Area
glArea = gtk_gl_area_new();
gtk_widget_set_vexpand(glArea, TRUE);
gtk_widget_set_hexpand(glArea, TRUE);
g_signal_connect(glArea, "realize", G_CALLBACK(on_realize), NULL);
g_signal_connect(glArea, "render", G_CALLBACK(on_render), NULL);
gtk_container_add(GTK_CONTAINER(window), glArea);
// Show widgets
gtk_widget_show_all(window);
gtk_main();
return 0;
}
static void on_realize(GtkGLArea *area) {
// Debug Message
int i;
g_print("on realize\n");
gtk_gl_area_make_current(area);
if(gtk_gl_area_get_error(area) != NULL) {
fprintf(stderr, "Unknown error\n");
return;
}
const GLubyte *renderer = glGetString(GL_RENDER);
const GLubyte *version = glGetString(GL_VERSION);
printf("Renderer: %s\n", renderer);
printf("OpenGL version supported %s\n", version);
glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
glGenVertexArrays(1, &vao);
glBindVertexArray(vao);
GLfloat player_vertices[] = {
-24.0, -24.0, 0.0, 0.0,
-24.0, 24.0, 0.0, 1.0,
24.0, 24.0, 1.0, 1.0,
-24.0, -24.0, 0.0, 0.0,
24.0, 24.0, 1.0, 1.0,
24.0, -24.0, 1.0, 0.0
};
glGenBuffers(1, &player.vbo[0]);
glBindBuffer(GL_ARRAY_BUFFER, player.vbo[0]);
glBufferData(
GL_ARRAY_BUFFER,
sizeof(player_vertices),
player_vertices,
GL_STATIC_DRAW
);
GLfloat bullet_vertices[] = {
-8.0, -8.0, 0.0, 0.0,
-8.0, 8.0, 0.0, 1.0,
8.0, 8.0, 1.0, 1.0,
-8.0, -8.0, 0.0, 0.0,
8.0, 8.0, 1.0, 1.0,
8.0, -8.0, 1.0, 0.0
};
glGenBuffers(1, &player.vbo[1]);
glBindBuffer(GL_ARRAY_BUFFER, player.vbo[1]);
glBufferData(
GL_ARRAY_BUFFER,
sizeof(bullet_vertices),
bullet_vertices,
GL_STATIC_DRAW
);
player.pos[0] = WIDTH / 2.0f;
player.pos[1] = HEIGHT / 2.0f;
player.pos[2] = 0.0;
player.left = FALSE;
player.right = FALSE;
player.up = FALSE;
player.space = FALSE;
mat4_translate(player.pos, player.mvp);
player.tex[0] = shader_load_texture("sprites/player.png");
player.tex[1] = shader_load_texture("sprites/bullet.png");
player.dx = 0.0f;
player.dy = 0.0f;
player.max = 8.0f;
player.bullet_speed = 6.0f;
player.num_ticks = 70;
for(i = 0; i < NUM_BULLETS; i++) {
player.bullets[i].active = FALSE;
}
// Astroids
astroid.radius = 40.0f;
GLfloat astroid_vertices[] = {
-astroid.radius, -astroid.radius, 0.0, 0.0,
-astroid.radius, astroid.radius, 0.0, 1.0,
astroid.radius, astroid.radius, 1.0, 1.0,
-astroid.radius, -astroid.radius, 0.0, 0.0,
astroid.radius, astroid.radius, 1.0, 1.0,
astroid.radius, -astroid.radius, 1.0, 0.0
};
glGenBuffers(1, &astroid.vbo);
glBindBuffer(GL_ARRAY_BUFFER, astroid.vbo);
glBufferData(
GL_ARRAY_BUFFER,
sizeof(astroid_vertices),
astroid_vertices,
GL_STATIC_DRAW
);
astroid.tex = shader_load_texture("sprites/astroid.png");
for(i = 0; i < NUM_ROCKS; i++) {
astroid.rocks[i].active = FALSE;
}
astroid.rocks[0].active = TRUE;
astroid.rocks[0].pos[0] = WIDTH / 4.0f;
astroid.rocks[0].pos[1] = HEIGHT / 4.0f;
astroid.rocks[0].pos[2] = 0.0f;
astroid.rocks[0].rot = M_PI / 3.0f;
astroid.rocks[0].dx = -0.3f;
astroid.rocks[0].dy = 0.4f;
astroid.rocks[0].size = 2;
astroid.rocks[1].active = TRUE;
astroid.rocks[1].pos[0] = WIDTH*3 / 4.0f;
astroid.rocks[1].pos[1] = HEIGHT*3 / 4.0f;
astroid.rocks[1].pos[2] = 0.0f;
astroid.rocks[1].rot = M_PI / 2.0f;
astroid.rocks[1].dx = 0.25f;
astroid.rocks[1].dy = -0.5f;
astroid.rocks[1].size = 2;
astroid.rocks[2].active = TRUE;
astroid.rocks[2].pos[0] = WIDTH*3 / 4.0f;
astroid.rocks[2].pos[1] = HEIGHT / 4.0f;
astroid.rocks[2].pos[2] = 0.0f;
astroid.rocks[2].rot = M_PI / 2.0f;
astroid.rocks[2].dx = -0.35f;
astroid.rocks[2].dy = 0.5f;
astroid.rocks[2].size = 2;
// Gameover Screen
GLfloat gameover_vertices[] = {
0.0, 0.0, 0.0, 0.0,
0.0, HEIGHT, 0.0, 1.0,
WIDTH, HEIGHT, 1.0, 1.0,
0.0, 0.0, 0.0, 0.0,
WIDTH, HEIGHT, 1.0, 1.0,
WIDTH, 0.0, 1.0, 0.0
};
glGenBuffers(1, &gameover.vbo);
glBindBuffer(GL_ARRAY_BUFFER, gameover.vbo);
glBufferData(
GL_ARRAY_BUFFER,
sizeof(gameover_vertices),
gameover_vertices,
GL_STATIC_DRAW
);
mat4_identity(gameover.mvp);
gameover.tex = shader_load_texture("sprites/gameover.png");
gameover.off = TRUE;
const char *vs = "shader/vertex.glsl";
const char *fs = "shader/fragment.glsl";
program = shader_load_program(vs, fs);
const char *attribute_name = "coord2d";
attribute_coord2d = glGetAttribLocation(program, attribute_name);
if(attribute_coord2d == -1) {
fprintf(stderr, "Could not bind attribute %s\n", attribute_name);
return;
}
const char *uniform_name = "orthograph";
GLint uniform_ortho = glGetUniformLocation(program, uniform_name);
if(uniform_ortho == -1) {
fprintf(stderr, "Could not bind uniform %s\n", uniform_name);
return;
}
uniform_name = "mvp";
uniform_mvp = glGetUniformLocation(program, uniform_name);
if(uniform_mvp == -1) {
fprintf(stderr, "Could not bind uniform %s\n", uniform_name);
return;
}
glUseProgram(program);
mat4 orthograph;
mat4_orthagonal(WIDTH, HEIGHT, orthograph);
glUniformMatrix4fv(uniform_ortho, 1, GL_FALSE, orthograph);
g_timeout_add(20, on_idle, (void*)area);
}
static void on_render(GtkGLArea *area, GdkGLContext *context) {
int i;
vec3 scale;
mat4 scl, pos, rot;
gboolean draw_mirror = FALSE;
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glUseProgram(program);
glBindVertexArray(vao);
glEnableVertexAttribArray(attribute_coord2d);
glEnableVertexAttribArray(attribute_texcoord);
// Draw bullet sprites
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, player.tex[1]);
glUniform1i(uniform_mytexture, 0);
for(i = 0; i < NUM_BULLETS; i++) {
if(!player.bullets[i].active) {
continue;
}
mat4_translate(player.bullets[i].pos, pos);
mat4_rotate_z(player.bullets[i].rot, rot);
mat4_multiply(pos, rot, player.mvp);
glUniformMatrix4fv(uniform_mvp, 1, GL_FALSE, player.mvp);
glBindBuffer(GL_ARRAY_BUFFER, player.vbo[1]);
glVertexAttribPointer(
attribute_coord2d,
2,
GL_FLOAT,
GL_FALSE,
sizeof(float) * 4,
0
);
glVertexAttribPointer(
attribute_texcoord,
2,
GL_FLOAT,
GL_FALSE,
sizeof(float) * 4,
(void*)(sizeof(float) * 2)
);
glDrawArrays(GL_TRIANGLES, 0, 6);
if(player.bullets[i].pos[0] > WIDTH - 24.0f) {
player.bullets[i].pos[0] -= WIDTH;
draw_mirror = TRUE;
} else if(player.bullets[i].pos[0] < 24.0f) {
player.bullets[i].pos[0] += WIDTH;
draw_mirror = TRUE;
}
if(player.bullets[i].pos[1] > HEIGHT - 24.0f) {
player.bullets[i].pos[1] -= HEIGHT;
draw_mirror = TRUE;
} else if(player.bullets[i].pos[1] < 24.0f) {
player.bullets[i].pos[1] += HEIGHT;
draw_mirror = TRUE;
}
if(!draw_mirror) {
continue;
}
mat4_translate(player.bullets[i].pos, pos);
mat4_rotate_z(player.bullets[i].rot, rot);
mat4_multiply(pos, rot, player.mvp);
glUniformMatrix4fv(uniform_mvp, 1, GL_FALSE, player.mvp);
glDrawArrays(GL_TRIANGLES, 0, 6);
draw_mirror = FALSE;
}
// Draw Player Sprite
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, player.tex[0]);
glUniform1i(uniform_mytexture, 0);
mat4_translate(player.pos, pos);
mat4_rotate_z(player.rot, rot);
mat4_multiply(pos, rot, player.mvp);
glUniformMatrix4fv(uniform_mvp, 1, GL_FALSE, player.mvp);
glBindBuffer(GL_ARRAY_BUFFER, player.vbo[0]);
glVertexAttribPointer(
attribute_coord2d,
2,
GL_FLOAT,
GL_FALSE,
sizeof(float) * 4,
0
);
glVertexAttribPointer(
attribute_texcoord,
2,
GL_FLOAT,
GL_FALSE,
sizeof(float) * 4,
(void*)(sizeof(float) * 2)
);
glDrawArrays(GL_TRIANGLES, 0, 6);
if(player.pos[0] > WIDTH - 24.0f) {
player.pos[0] -= WIDTH;
draw_mirror = TRUE;
} else if(player.pos[0] < 24.0f) {
player.pos[0] += WIDTH;
draw_mirror = TRUE;
}
if(player.pos[1] > HEIGHT - 24.0f) {
player.pos[1] -= HEIGHT;
draw_mirror = TRUE;
} else if(player.pos[1] < 24.0f) {
player.pos[1] += HEIGHT;
draw_mirror = TRUE;
}
if(draw_mirror) {
draw_mirror = FALSE;
mat4_translate(player.pos, pos);
mat4_rotate_z(player.rot, rot);
mat4_multiply(pos, rot, player.mvp);
glUniformMatrix4fv(uniform_mvp, 1, GL_FALSE, player.mvp);
glDrawArrays(GL_TRIANGLES, 0, 6);
}
// Draw Astroid Sprites
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, astroid.tex);
glUniform1i(uniform_mytexture, 0);
for(i = 0; i < NUM_ROCKS; i++) {
if(!astroid.rocks[i].active) {
continue;
}
switch(astroid.rocks[i].size) {
case 2:
scale[0] = 1.4f;
scale[1] = 1.4f;
scale[2] = 1.0f;
break;
case 1:
scale[0] = 0.5f;
scale[1] = 0.5f;
scale[2] = 1.0f;
break;
case 0:
scale[0] = 0.25f;
scale[1] = 0.25f;
scale[2] = 1.0f;
break;
}
mat4_scale(scale, scl);
mat4_translate(astroid.rocks[i].pos, pos);
mat4_rotate_z(astroid.rocks[i].rot, rot);
mat4_multiply(pos, rot, astroid.mvp);
mat4_multiply(astroid.mvp, scl, astroid.mvp);
glUniformMatrix4fv(uniform_mvp, 1, GL_FALSE, astroid.mvp);
glBindBuffer(GL_ARRAY_BUFFER, astroid.vbo);
glVertexAttribPointer(
attribute_coord2d,
2,
GL_FLOAT,
GL_FALSE,
sizeof(float) * 4,
0
);
glVertexAttribPointer(
attribute_texcoord,
2,
GL_FLOAT,
GL_FALSE,
sizeof(float) * 4,
(void*)(sizeof(float) * 2)
);
glDrawArrays(GL_TRIANGLES, 0, 6);
if(astroid.rocks[i].pos[0] > WIDTH - astroid.radius*scale[0]) {
astroid.rocks[i].pos[0] -= WIDTH;
draw_mirror = TRUE;
} else if(astroid.rocks[i].pos[0] < astroid.radius*scale[0]) {
astroid.rocks[i].pos[0] += WIDTH;
draw_mirror = TRUE;
}
if(astroid.rocks[i].pos[1] > HEIGHT - astroid.radius*scale[0]) {
astroid.rocks[i].pos[1] -= HEIGHT;
draw_mirror = TRUE;
} else if(astroid.rocks[i].pos[1] < astroid.radius*scale[0]) {
astroid.rocks[i].pos[1] += HEIGHT;
draw_mirror = TRUE;
}
if(!draw_mirror) {
continue;
}
draw_mirror = FALSE;
mat4_translate(astroid.rocks[i].pos, pos);
mat4_rotate_z(astroid.rocks[i].rot, rot);
mat4_multiply(pos, rot, astroid.mvp);
mat4_multiply(astroid.mvp, scl, astroid.mvp);
glUniformMatrix4fv(uniform_mvp, 1, GL_FALSE, astroid.mvp);
glDrawArrays(GL_TRIANGLES, 0, 6);
}
if(!gameover.off) {
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, gameover.tex);
glUniform1i(uniform_mytexture, 0);
glUniformMatrix4fv(uniform_mvp, 1, GL_FALSE, gameover.mvp);
glBindBuffer(GL_ARRAY_BUFFER, gameover.vbo);
glVertexAttribPointer(
attribute_coord2d,
2,
GL_FLOAT,
GL_FALSE,
sizeof(float) * 4,
0
);
glVertexAttribPointer(
attribute_texcoord,
2,
GL_FLOAT,
GL_FALSE,
sizeof(float) * 4,
(void*)(sizeof(float) * 2)
);
glDrawArrays(GL_TRIANGLES, 0, 6);
}
glDisableVertexAttribArray(attribute_coord2d);
glDisableVertexAttribArray(attribute_texcoord);
}
static gboolean on_idle(gpointer data) {
if(!gameover.off) {
return TRUE;
}
if(player.right) {
player.rot -= 0.05f;
}
if(player.left) {
player.rot += 0.05f;
}
int i, k, j, split, index;
float scale, dx, dy, x_dif, y_dif;
split = 0;
if(player.up) {
player.dx -= sin(player.rot) * 0.05;
player.dy += cos(player.rot) * 0.05;
}
if(player.dx < -player.max) {
player.dx = -player.max;
} else if(player.dx > player.max) {
player.dx = player.max;
}
if(player.dy < -player.max) {
player.dy = -player.max;
} else if(player.dy > player.max) {
player.dy = player.max;
}
player.pos[0] += player.dx;
player.pos[1] += player.dy;
for(i = 0; i < NUM_BULLETS; i++) {
if(!player.bullets[i].active) {
continue;
}
if(player.bullets[i].ticks < 0) {
player.bullets[i].active = FALSE;
}
dx = sin(player.bullets[i].rot) * player.bullet_speed;
dy = cos(player.bullets[i].rot) * player.bullet_speed;
player.bullets[i].pos[0] -= dx;
player.bullets[i].pos[1] += dy;
player.bullets[i].ticks--;
for(k = 0; k < NUM_ROCKS; k++) {
if(!astroid.rocks[k].active) {
continue;
}
switch(astroid.rocks[k].size) {
case 2:
scale = 1.4f;
break;
case 1:
scale = 0.5f;
break;
case 0:
scale = 0.25f;
break;
}
x_dif = player.bullets[i].pos[0] - astroid.rocks[k].pos[0];
y_dif = player.bullets[i].pos[1] - astroid.rocks[k].pos[1];
if(hypotf(x_dif, y_dif) > astroid.radius * scale) {
continue;
}
astroid.rocks[k].active = FALSE;
player.bullets[i].active = FALSE;
if(astroid.rocks[k].size) {
split = 2;
index = k;
}
break;
}
if(!split) {
continue;
}
for(k = 0; k < NUM_ROCKS; k++) {
if(k == index) {
continue;
}
if(astroid.rocks[k].active) {
continue;
}
astroid.rocks[k].active = TRUE;
astroid.rocks[k].size = astroid.rocks[index].size - 1;
astroid.rocks[k].rot = (float)(rand() % 1000) / 1000.f * M_PI;
vec3_copy(astroid.rocks[index].pos, astroid.rocks[k].pos);
switch(split) {
case 2:
astroid.rocks[k].dx = astroid.rocks[index].dx * 1.2f;
astroid.rocks[k].dy = astroid.rocks[index].dy * -1.2f;
break;
case 1:
astroid.rocks[k].dx = astroid.rocks[index].dx * -1.2f;
astroid.rocks[k].dy = astroid.rocks[index].dy * 1.2f;
break;
}
split--;
if(!split) {
break;
}
}
}
for(i = 0; i < NUM_ROCKS; i++) {
if(!astroid.rocks[i].active) {
continue;
}
astroid.rocks[i].pos[0] += astroid.rocks[i].dx;
astroid.rocks[i].pos[1] += astroid.rocks[i].dy;
if(!gameover.off) {
continue;
}
x_dif = player.pos[0] - astroid.rocks[i].pos[0];
y_dif = player.pos[1] - astroid.rocks[i].pos[1];
switch(astroid.rocks[i].size) {
case 2:
scale = 1.4f;
break;
case 1:
scale = 0.5f;
break;
case 0:
scale = 0.25f;
break;
}
if(hypotf(x_dif, y_dif) > astroid.radius * scale) {
continue;
}
g_print("Gameover detected!!\n");
gameover.off = FALSE;
}
gtk_widget_queue_draw(GTK_WIDGET(data));
return TRUE;
}
static gboolean on_keydown(GtkWidget *widget, GdkEventKey *event) {
switch(event->keyval) {
case GDK_KEY_Left:
player.left = TRUE;
break;
case GDK_KEY_Right:
player.right = TRUE;
break;
case GDK_KEY_Up:
player.up = TRUE;
break;
case GDK_KEY_space:
if(!player.space) {
int i;
for(i = 0; i < NUM_BULLETS; i++) {
if(player.bullets[i].active) {
continue;
}
player.bullets[i].active = TRUE;
player.bullets[i].pos[0] = player.pos[0];
player.bullets[i].pos[1] = player.pos[1];
player.bullets[i].pos[2] = player.pos[2];
player.bullets[i].rot = player.rot;
player.bullets[i].ticks = player.num_ticks;
break;
}
}
player.space = TRUE;
break;
case GDK_KEY_r:
if(!gameover.off) {
reset_game();
}
break;
}
}
static gboolean on_keyup(GtkWidget *widget, GdkEventKey *event) {
switch(event->keyval) {
case GDK_KEY_Left:
player.left = FALSE;
break;
case GDK_KEY_Right:
player.right = FALSE;
break;
case GDK_KEY_Up:
player.up = FALSE;
break;
case GDK_KEY_space:
player.space = FALSE;
break;
}
}
static void reset_game() {
int i;
player.pos[0] = WIDTH / 2.0f;
player.pos[1] = HEIGHT / 2.0f;
player.pos[2] = 0.0;
player.dx = 0.0;
player.dy = 0.0;
player.rot = 0.0;
player.left = FALSE;
player.right = FALSE;
player.up = FALSE;
player.space = FALSE;
for(i = 0; i < NUM_BULLETS; i++) {
player.bullets[i].active = FALSE;
}
for(i = 0; i < NUM_ROCKS; i++) {
astroid.rocks[i].active = FALSE;
}
astroid.rocks[0].active = TRUE;
astroid.rocks[0].pos[0] = WIDTH / 4.0f;
astroid.rocks[0].pos[1] = HEIGHT / 4.0f;
astroid.rocks[0].pos[2] = 0.0f;
astroid.rocks[0].rot = M_PI / 3.0f;
astroid.rocks[0].dx = -0.3f;
astroid.rocks[0].dy = 0.4f;
astroid.rocks[0].size = 2;
astroid.rocks[1].active = TRUE;
astroid.rocks[1].pos[0] = WIDTH*3 / 4.0f;
astroid.rocks[1].pos[1] = HEIGHT*3 / 4.0f;
astroid.rocks[1].pos[2] = 0.0f;
astroid.rocks[1].rot = M_PI / 2.0f;
astroid.rocks[1].dx = 0.25f;
astroid.rocks[1].dy = -0.5f;
astroid.rocks[1].size = 2;
astroid.rocks[2].active = TRUE;
astroid.rocks[2].pos[0] = WIDTH*3 / 4.0f;
astroid.rocks[2].pos[1] = HEIGHT / 4.0f;
astroid.rocks[2].pos[2] = 0.0f;
astroid.rocks[2].rot = M_PI / 2.0f;
astroid.rocks[2].dx = -0.35f;
astroid.rocks[2].dy = 0.5f;
astroid.rocks[2].size = 2;
gameover.off = TRUE;
}
Compile
$ gcc -c -o DashGL/dashgl.o DashGL/dashgl.c -lepoxy -lpng -lm
$ gcc `pkg-config --cflags gtk+-3.0` main.c DashGL/dashgl.o `pkg-config --libs gtk+-3.0` \
-lepoxy -lm -lpng
Run
$ ./a.out