screen_shape(const program& prog)
{
gl.bind(vao);
GLfloat position_data[4*2] = {
-1.0f, -1.0f,
-1.0f, 1.0f,
1.0f, -1.0f,
1.0f, 1.0f
};
gl.bind(GL.array_buffer, positions);
gl.buffer_data(GL.array_buffer, position_data, GL.static_draw);
vertex_attrib_location va_p;
gl.query_location(va_p, prog, "Position");
gl.vertex_array_attrib_pointer(
va_p,
2, GL.float_,
false, 0, nullptr
);
gl.enable_vertex_array_attrib(va_p);
GLfloat coord_data[4*2] = {
-1.0f, -1.0f,
-1.0f, 1.0f,
1.0f, -1.0f,
1.0f, 1.0f
};
gl.bind(GL.array_buffer, coords);
gl.buffer_data(GL.array_buffer, coord_data, GL.static_draw);
vertex_attrib_location va_c;
gl.query_location(va_c, prog, "TexCoord");
gl.vertex_array_attrib_pointer(
va_c,
2, GL.float_,
false, 0, nullptr
);
gl.enable_vertex_array_attrib(va_c);
}
cube_model(const program& prog)
{
const GLfloat v[8][3] = {
{-0.5f, -0.5f, -0.5f},
{+0.5f, -0.5f, -0.5f},
{-0.5f, +0.5f, -0.5f},
{+0.5f, +0.5f, -0.5f},
{-0.5f, -0.5f, +0.5f},
{+0.5f, -0.5f, +0.5f},
{-0.5f, +0.5f, +0.5f},
{+0.5f, +0.5f, +0.5f}
};
const GLint f[6][2][3] = {
{{0, 4, 2}, {2, 4, 6}},
{{5, 1, 7}, {7, 1, 3}},
{{0, 1, 4}, {4, 1, 5}},
{{6, 7, 2}, {2, 7, 3}},
{{1, 0, 3}, {3, 0, 2}},
{{4, 5, 6}, {6, 5, 7}}
};
gl.bind(vao);
const GLuint vertex_count = 6 * 2 * 3;
// positions
GLfloat vertex_data[vertex_count * 3];
for(GLuint fi=0;fi!=6;++fi)
for(GLuint ti=0;ti!=2;++ti)
for(GLuint vi=0;vi!=3;++vi)
{
for(GLuint ci=0;ci!=3;++ci)
{
vertex_data[fi*2*3*3+ti*3*3+vi*3+ci] =
v[f[fi][ti][vi]][ci];
}
}
gl.bind(GL.array_buffer, positions);
gl.buffer_data(GL.array_buffer, vertex_data, GL.static_draw);
gl.vertex_array_attrib_pointer(
vertex_attrib_location(0),
3, GL.float_,
false, 0, nullptr
);
gl.enable_vertex_array_attrib(vertex_attrib_location(0));
vertex_attrib_location va_p;
gl.query_location(va_p, prog, "Position");
gl.vertex_array_attrib_pointer(
va_p, 3, GL.float_,
false, 0, nullptr
);
gl.enable_vertex_array_attrib(va_p);
// normals
const GLfloat n[6][3] = {
{-1.0f, 0.0f, 0.0f},
{ 1.0f, 0.0f, 0.0f},
{ 0.0f, -1.0f, 0.0f},
{ 0.0f, 1.0f, 0.0f},
{ 0.0f, 0.0f, -1.0f},
{ 0.0f, 0.0f, 1.0f}
};
for(GLuint fi=0;fi!=6;++fi)
for(GLuint vi=0;vi!=6;++vi)
{
for(GLuint ci=0;ci!=3;++ci)
{
vertex_data[(fi*6+vi)*3+ci] = n[fi][ci];
}
}
gl.bind(GL.array_buffer, normals);
gl.buffer_data(GL.array_buffer, vertex_data, GL.static_draw);
vertex_attrib_location va_n;
gl.query_location(va_n, prog, "Normal");
gl.vertex_array_attrib_pointer(
va_n, 3, GL.float_,
false, 0, nullptr
);
gl.enable_vertex_array_attrib(va_n);
// tex-coords
const GLfloat c[6][2] = {
{0.0f, 0.0f},
{1.0f, 0.0f},
{0.0f, 1.0f},
{0.0f, 1.0f},
{1.0f, 0.0f},
{1.0f, 1.0f}
};
for(GLuint fi=0;fi!=6;++fi)
{
for(GLuint vi=0;vi!=6;++vi)
{
for(GLuint ci=0;ci!=2;++ci)
{
vertex_data[(fi*6+vi)*2+ci] = c[vi][ci];
}
}
}
gl.bind(GL.array_buffer, texcoords);
gl.buffer_data(
GL.array_buffer,
buffer_data_spec{vertex_data, vertex_count * 2},
GL.static_draw
);
vertex_attrib_location va_c;
gl.query_location(va_c, prog, "TexCoord");
gl.vertex_array_attrib_pointer(
va_c, 2, GL.float_,
false, 0, nullptr
);
gl.enable_vertex_array_attrib(va_c);
}
example_mandelbrot(void)
: offset_x(-0.5f)
, offset_y(0.0f)
, scale(1.0f)
, aspect(1.0f)
{
shader vs(GL.vertex_shader);
vs.source(glsl_literal(
"#version 130\n"
"uniform vec2 Offset;\n"
"uniform vec2 Scale;\n"
"in vec2 Position;\n"
"in vec2 Coord;\n"
"out vec2 vertCoord;\n"
"void main(void)\n"
"{\n"
" vertCoord = Coord*Scale+Offset;\n"
" gl_Position = vec4(Position, 0.0, 1.0);\n"
"}\n"
));
vs.compile();
shader fs(GL.fragment_shader);
fs.source(glsl_literal(
"#version 130\n"
"uniform sampler1D gradient;\n"
"in vec2 vertCoord;\n"
"out vec4 fragColor;\n"
"void main(void)\n"
"{\n"
" vec2 z = vec2(0.0, 0.0);\n"
" vec2 c = vertCoord;\n"
" int i = 0, max = 256;\n"
" while((i != max) && (distance(z, c) < 2.0))\n"
" {\n"
" vec2 zn = vec2(\n"
" z.x * z.x - z.y * z.y + c.x,\n"
" 2.0 * z.x * z.y + c.y\n"
" );\n"
" z = zn;\n"
" ++i;\n"
" }\n"
" float a = float(i)/float(max);\n"
" fragColor = texture(gradient, a+sqrt(length(c))*0.1);\n"
"} \n"
));
fs.compile();
prog.attach(vs);
prog.attach(fs);
prog.link();
gl.use(prog);
gl.query_location(offset_loc, prog, "Offset");
gl.query_location(scale_loc, prog, "Scale");
gl.uniform(offset_loc, offset_x, offset_y);
gl.bind(vao);
GLfloat position_data[4*2] = {
-1.0f, -1.0f,
-1.0f, 1.0f,
1.0f, -1.0f,
1.0f, 1.0f
};
gl.bind(GL.array_buffer, positions);
gl.buffer_data(GL.array_buffer, position_data, GL.static_draw);
vertex_attrib_location va_p;
gl.query_location(va_p, prog, "Position");
gl.vertex_array_attrib_pointer(
va_p,
2, GL.float_,
false, 0, nullptr
);
gl.enable_vertex_array_attrib(va_p);
GLfloat coord_data[4*2] = {
-1.0f, -1.0f,
-1.0f, 1.0f,
1.0f, -1.0f,
1.0f, 1.0f
};
gl.bind(GL.array_buffer, coords);
gl.buffer_data(GL.array_buffer, coord_data, GL.static_draw);
vertex_attrib_location va_c;
gl.query_location(va_c, prog, "Coord");
gl.vertex_array_attrib_pointer(
va_c,
2, GL.float_,
false, 0, nullptr
);
gl.enable_vertex_array_attrib(va_c);
GLfloat gradient_data[8*3];
for(int i=0; i<8*3; ++i)
{
gradient_data[i] = (std::rand() % 10000) / 10000.f;
}
gl.bind(GL.texture_1d, gradient);
gl.texture_min_filter(GL.texture_1d, GL.linear);
gl.texture_mag_filter(GL.texture_1d, GL.linear);
gl.texture_wrap(
GL.texture_1d,
GL.texture_wrap_s,
GL.repeat
);
gl.texture_image_1d(
GL.texture_1d,
0, GL.rgb,
8,
0, GL.rgb,
GL.float_,
const_memory_block{gradient_data}
);
gl.disable(GL.depth_test);
}