1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
|
//
// Copyright 2014 The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
// Based on Hello_Triangle.c from
// Book: OpenGL(R) ES 2.0 Programming Guide
// Authors: Aaftab Munshi, Dan Ginsburg, Dave Shreiner
// ISBN-10: 0321502795
// ISBN-13: 9780321502797
// Publisher: Addison-Wesley Professional
// URLs: http://safari.informit.com/9780321563835
// http://www.opengles-book.com
#include "SampleApplication.h"
#include "util/shader_utils.h"
class HelloTriangleSample : public SampleApplication
{
public:
HelloTriangleSample(int argc, char **argv) : SampleApplication("HelloTriangle", argc, argv) {}
bool initialize() override
{
constexpr char kVS[] = R"(attribute vec4 vPosition;
void main()
{
gl_Position = vPosition;
})";
constexpr char kFS[] = R"(precision mediump float;
void main()
{
gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
})";
mProgram = CompileProgram(kVS, kFS);
if (!mProgram)
{
return false;
}
glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
return true;
}
void destroy() override { glDeleteProgram(mProgram); }
void draw() override
{
GLfloat vertices[] = {
0.0f, 0.5f, 0.0f, -0.5f, -0.5f, 0.0f, 0.5f, -0.5f, 0.0f,
};
// Set the viewport
glViewport(0, 0, getWindow()->getWidth(), getWindow()->getHeight());
// Clear the color buffer
glClear(GL_COLOR_BUFFER_BIT);
// Use the program object
glUseProgram(mProgram);
// Load the vertex data
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, vertices);
glEnableVertexAttribArray(0);
glDrawArrays(GL_TRIANGLES, 0, 3);
}
private:
GLuint mProgram;
};
int main(int argc, char **argv)
{
HelloTriangleSample app(argc, argv);
return app.run();
}
|
