source: trunk/tutorial/08_fbo.cpp @ 1730

Last change on this file since 1730 was 1730, checked in by sam, 8 years ago

tutorial: make the FBO example display something at last, so we can port
it to DirectX.

File size: 4.0 KB
Line 
1//
2// Lol Engine - Framebuffer Object tutorial
3//
4// Copyright: (c) 2012 Sam Hocevar <sam@hocevar.net>
5//   This program is free software; you can redistribute it and/or
6//   modify it under the terms of the Do What The Fuck You Want To
7//   Public License, Version 2, as published by Sam Hocevar. See
8//   http://sam.zoy.org/projects/COPYING.WTFPL for more details.
9//
10
11#if defined HAVE_CONFIG_H
12#   include "config.h"
13#endif
14
15#include "core.h"
16#include "loldebug.h"
17#include "lolgl.h"
18
19using namespace std;
20using namespace lol;
21
22#if defined _WIN32
23#   include <direct.h>
24#endif
25
26extern char const *lolfx_08_fbo;
27
28class FBO : public WorldEntity
29{
30public:
31    FBO()
32    {
33        m_vertices << vec2( 1.0,  1.0);
34        m_vertices << vec2(-1.0, -1.0);
35        m_vertices << vec2( 1.0, -1.0);
36        m_vertices << vec2(-1.0, -1.0);
37        m_vertices << vec2( 1.0,  1.0);
38        m_vertices << vec2(-1.0,  1.0);
39        m_ready = false;
40    }
41
42    virtual void TickGame(float seconds)
43    {
44        WorldEntity::TickGame(seconds);
45
46        m_time += seconds;
47        m_hotspot = 0.4f * vec3(lol::cos(m_time * 2.f) + lol::cos(m_time * 3.3f),
48                                lol::sin(m_time * 4.4f) + lol::sin(m_time * 3.2f),
49                                lol::sin(m_time * 5.f));
50        m_color = 0.25f * vec3(3.f + lol::sin(m_time * 4.5f + 1.f),
51                               3.f + lol::sin(m_time * 2.8f + 1.3f),
52                               3.f + lol::sin(m_time * 3.7f));
53    }
54
55    virtual void TickDraw(float seconds)
56    {
57        WorldEntity::TickDraw(seconds);
58
59        if (!m_ready)
60        {
61            m_shader = Shader::Create(lolfx_08_fbo);
62            m_coord = m_shader->GetAttribLocation("in_Position", VertexUsage::Position, 0);
63            m_uni_point = m_shader->GetUniformLocation("in_Point");
64            m_uni_color = m_shader->GetUniformLocation("in_Color");
65            m_uni_flag = m_shader->GetUniformLocation("in_Flag");
66            m_uni_texture = m_shader->GetUniformLocation("in_Texture");
67
68            m_vdecl = new VertexDeclaration(VertexStream<vec2>(VertexUsage::Position));
69
70            m_vbo = new VertexBuffer(m_vertices.Bytes());
71            void *vertices = m_vbo->Lock(0, 0);
72            memcpy(vertices, &m_vertices[0], m_vertices.Bytes());
73            m_vbo->Unlock();
74
75            m_fbo = new FrameBuffer(Video::GetSize());
76            m_fbo->Bind();
77            glClearColor(0.0, 0.0, 0.0, 1.0f);
78            glClearDepth(1.0f);
79            glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
80            m_fbo->Unbind();
81
82            m_ready = true;
83
84            /* FIXME: this object never cleans up */
85        }
86
87        m_fbo->Bind();
88        /* FIXME: we should just disable depth test in the shader */
89        glClear(GL_DEPTH_BUFFER_BIT);
90        m_shader->Bind();
91        m_shader->SetUniform(m_uni_flag, 0.f);
92        m_shader->SetUniform(m_uni_point, m_hotspot);
93        m_shader->SetUniform(m_uni_color, m_color);
94        m_vdecl->SetStream(m_vbo, m_coord);
95        m_vdecl->Bind();
96        m_vdecl->DrawElements(MeshPrimitive::Triangles, 0, 2);
97        m_vdecl->Unbind();
98        m_shader->Unbind();
99        m_fbo->Unbind();
100
101        m_shader->Bind();
102        m_shader->SetUniform(m_uni_flag, 1.f);
103        m_shader->SetTexture(m_uni_texture, m_fbo->GetTexture(), 0);
104        m_vdecl->SetStream(m_vbo, m_coord);
105        m_vdecl->Bind();
106        m_vdecl->DrawElements(MeshPrimitive::Triangles, 0, 2);
107        m_vdecl->Unbind();
108        m_shader->Unbind();
109    }
110
111private:
112    Array<vec2> m_vertices;
113    Shader *m_shader;
114    ShaderAttrib m_coord;
115    ShaderUniform m_uni_flag, m_uni_point, m_uni_color, m_uni_texture;
116    VertexDeclaration *m_vdecl;
117    VertexBuffer *m_vbo;
118    FrameBuffer *m_fbo;
119    double m_time;
120    vec3 m_hotspot, m_color;
121    bool m_ready;
122};
123
124int main(int argc, char **argv)
125{
126    Application app("Tutorial 08: Framebuffer Object", ivec2(640, 480), 60.0f);
127
128#if defined _MSC_VER && !defined _XBOX
129    _chdir("..");
130#elif defined _WIN32 && !defined _XBOX
131    _chdir("../..");
132#endif
133
134    new FBO();
135
136    app.Run();
137    return EXIT_SUCCESS;
138}
139
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