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/*
* Copyright © 2014 Canonical Ltd.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 3 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* Author: Daniel van Vugt <daniel.van.vugt@canonical.com>
* Alberto Aguirre <alberto.aguirre@canonical.com>
*/
#include "eglapp.h"
#include <assert.h>
#include <stdio.h>
#include <GLES2/gl2.h>
#include <vector>
#include <stdexcept>
#include <iostream>
#include <algorithm>
static GLuint load_shader(const char *src, GLenum type)
{
GLuint shader = glCreateShader(type);
if (shader)
{
GLint compiled;
glShaderSource(shader, 1, &src, NULL);
glCompileShader(shader);
glGetShaderiv(shader, GL_COMPILE_STATUS, &compiled);
if (!compiled)
{
GLchar log[1024];
glGetShaderInfoLog(shader, sizeof log - 1, NULL, log);
log[sizeof log - 1] = '\0';
printf("load_shader compile failed: %s\n", log);
glDeleteShader(shader);
shader = 0;
}
}
return shader;
}
class DrawableDigit
{
public:
DrawableDigit(std::initializer_list<std::vector<GLubyte>> list)
{
for (auto const& arg : list)
{
indices.insert(indices.end(), arg.begin(), arg.end());
}
}
void draw()
{
glDrawElements(GL_TRIANGLES, indices.size(), GL_UNSIGNED_BYTE, indices.data());
}
private:
DrawableDigit() = delete;
std::vector<GLubyte> indices;
};
class TwoDigitCounter
{
public:
TwoDigitCounter(GLuint prog, float thickness, unsigned int max_count)
: count{0}, max_count{std::min(max_count, 99u)}, program{prog},
vertices{create_vertices(thickness)}, digit_drawables{create_digits()}
{
vpos = glGetAttribLocation(program, "vPosition");
if (vpos == -1)
throw std::runtime_error("Failed to obtain vPosition attribute");
xoff = glGetUniformLocation(program, "xOffset");
if (xoff == -1)
throw std::runtime_error("Failed to obtain xoff uniform");
xscale = glGetUniformLocation(program, "xScale");
if (xscale == -1)
throw std::runtime_error("Failed to obtain xscale uniform");
glUniform1f(xscale, 0.4f);
glVertexAttribPointer(vpos, 2, GL_FLOAT, GL_FALSE, 0, vertices.data());
glEnableVertexAttribArray(0);
}
void draw()
{
drawLeftDigit();
drawRightDigit();
nextCount();
}
private:
void draw(int digit)
{
if (static_cast<size_t>(digit) > digit_drawables.size())
throw std::logic_error("invalid digit to draw");
digit_drawables[digit].draw();
}
void drawRightDigit()
{
glUniform1f(xoff, 0.5f);
draw(count % 10);
}
void drawLeftDigit()
{
glUniform1f(xoff, -0.5f);
draw(count/10);
}
void nextCount()
{
count++;
if (count > max_count) count = 0;
}
static std::vector<GLfloat> create_vertices(GLfloat t)
{
return std::vector<GLfloat>{
-1.0f, -1.0f,
-1.0f+t, -1.0f,
1.0f-t, -1.0f,
1.0f, -1.0f,
-1.0f, -1.0f+t,
1.0f, -1.0f+t,
-1.0f, -t/2.0f,
-1.0f+t, -t/2.0f,
1.0f-t, -t/2.0f,
1.0f, -t/2.0f,
-1.0f, t/2.0f,
1.0f, t/2.0f,
-1.0f, 1.0f-t,
1.0f, 1.0f-t,
-1.0f, 1.0f,
-1.0f+t, 1.0f,
1.0f-t, 1.0f,
1.0f, 1.0f,
};
}
static std::vector<DrawableDigit> create_digits()
{
std::vector<DrawableDigit> digits;
/*
* Vertex indices for quads which can be used to make
* simple number "font" shapes
*/
std::vector<GLubyte> top{12, 14, 13, 13, 14, 17};
std::vector<GLubyte> bottom{0, 4, 3, 3, 4, 5};
std::vector<GLubyte> middle{6, 10, 9, 9, 10, 11};
std::vector<GLubyte> left{0, 14, 1, 1, 14, 15};
std::vector<GLubyte> right{2, 16, 3, 3, 16, 17};
std::vector<GLubyte> top_left{6, 14, 7, 7, 14, 15};
std::vector<GLubyte> top_right{8, 16, 9, 9, 16, 17};
std::vector<GLubyte> bottom_left{0, 6, 1, 1, 6, 7};
std::vector<GLubyte> bottom_right{2, 8, 3, 3, 8, 9};
digits.push_back({top, bottom, left, right});
digits.push_back({right});
digits.push_back({top, middle, bottom, top_right, bottom_left});
digits.push_back({top, middle, bottom, right});
digits.push_back({top_left, middle, right});
digits.push_back({top, middle, bottom, top_left, bottom_right});
digits.push_back({top, middle, bottom, left, bottom_right});
digits.push_back({top, right});
digits.push_back({top, middle, bottom, left, right});
digits.push_back({top, middle, right, top_left});
return digits;
}
unsigned int count;
unsigned int const max_count;
GLint vpos;
GLint xoff;
GLint xscale;
GLuint program;
std::vector<GLfloat> const vertices;
std::vector<DrawableDigit> digit_drawables;
};
/* Colours from http://design.ubuntu.com/brand/colour-palette */
#define MID_AUBERGINE(x) (x)*0.368627451f, (x)*0.152941176f, (x)*0.31372549f
#define ORANGE 0.866666667f, 0.282352941f, 0.141414141f
int main(int argc, char *argv[])
{
const char vshadersrc[] =
"attribute vec4 vPosition; \n"
"uniform float xOffset; \n"
"uniform float xScale; \n"
"void main() \n"
"{ \n"
" vec4 vertex; \n"
" vertex = vPosition; \n"
" vertex.x *= xScale; \n"
" vertex.x += xOffset; \n"
" gl_Position = vertex; \n"
"} \n";
const char fshadersrc[] =
"precision mediump float; \n"
"uniform vec4 col; \n"
"void main() \n"
"{ \n"
" gl_FragColor = col; \n"
"} \n";
GLuint vshader, fshader, prog;
GLint linked, col;
unsigned int width = 512, height = 256;
if (!mir_eglapp_init(argc, argv, &width, &height))
return 1;
vshader = load_shader(vshadersrc, GL_VERTEX_SHADER);
assert(vshader);
fshader = load_shader(fshadersrc, GL_FRAGMENT_SHADER);
assert(fshader);
prog = glCreateProgram();
assert(prog);
glAttachShader(prog, vshader);
glAttachShader(prog, fshader);
glLinkProgram(prog);
glGetProgramiv(prog, GL_LINK_STATUS, &linked);
if (!linked)
{
GLchar log[1024];
glGetProgramInfoLog(prog, sizeof log - 1, NULL, log);
log[sizeof log - 1] = '\0';
printf("Link failed: %s\n", log);
return 2;
}
float const opacity = mir_eglapp_background_opacity;
glClearColor(MID_AUBERGINE(opacity), opacity);
glViewport(0, 0, width, height);
glUseProgram(prog);
col = glGetUniformLocation(prog, "col");
glUniform4f(col, ORANGE, 1.0f);
float thickness = 0.2f;
unsigned int max_counter = 60;
TwoDigitCounter counter(prog, thickness, max_counter);
while (mir_eglapp_running())
{
glClear(GL_COLOR_BUFFER_BIT);
counter.draw();
mir_eglapp_swap_buffers();
}
mir_eglapp_shutdown();
return 0;
}
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