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3D C/C++ tutorials -> OpenGL 2.1 -> Deferred rendering - Point lights
Use for personal or educational purposes only. Commercial and other profit uses strictly prohibited. Exploitation of content on a website or in a publication prohibited.
To compile and run these tutorials some or all of these libraries are required: FreeImage 3.16.0, GLEW 1.11.0, GLUT 3.7.6 / GLUT for Dev-C++, GLM 0.9.5.4
opengl_21_tutorials_win32_framework.h
...
class COpenGLRenderer
{
protected:
...
mat4x4 ..., ProjectionBiasInverse;
protected:
CTexture Texture[3];
CShaderProgram Preprocess, DeferredLighting;
GLuint ColorBuffer, NormalBuffer, DepthBuffer;
GLuint VBO, FBO;
public:
bool Pause;
vec3 LightColors[4], LightPositions[4];
public:
...
protected:
void InitArrayBuffers();
};
...
opengl_21_tutorials_win32_framework.cpp
...
COpenGLRenderer::COpenGLRenderer()
{
Pause = false;
Camera.SetViewMatrixPointer(&ViewMatrix);
}
COpenGLRenderer::~COpenGLRenderer()
{
}
bool COpenGLRenderer::Init()
{
// ------------------------------------------------------------------------------------------------------------------------
bool Error = false;
// ------------------------------------------------------------------------------------------------------------------------
if(!GLEW_ARB_texture_non_power_of_two)
{
ErrorLog.Append("GL_ARB_texture_non_power_of_two not supported!\r\n");
Error = true;
}
if(!GLEW_ARB_depth_texture)
{
ErrorLog.Append("GLEW_ARB_depth_texture not supported!\r\n");
Error = true;
}
if(!GLEW_EXT_framebuffer_object)
{
ErrorLog.Append("GL_EXT_framebuffer_object not supported!\r\n");
Error = true;
}
// ------------------------------------------------------------------------------------------------------------------------
char *TextureFileName[] = {"cube.jpg", "floor.jpg", "wall.jpg"};
for(int i = 0; i < 3; i++)
{
Error |= !Texture[i].LoadTexture2D(TextureFileName[i]);
}
// ------------------------------------------------------------------------------------------------------------------------
Error |= !Preprocess.Load("preprocess.vs", "preprocess.fs");
Error |= !DeferredLighting.Load("deferredlighting.vs", "deferredlighting.fs");
// ------------------------------------------------------------------------------------------------------------------------
if(Error)
{
return false;
}
// ------------------------------------------------------------------------------------------------------------------------
Preprocess.UniformLocations = new GLuint[1];
Preprocess.UniformLocations[0] = glGetUniformLocation(Preprocess, "Texturing");
DeferredLighting.UniformLocations = new GLuint[1];
DeferredLighting.UniformLocations[0] = glGetUniformLocation(DeferredLighting, "ProjectionBiasMatrixInverse");
// ------------------------------------------------------------------------------------------------------------------------
glUseProgram(DeferredLighting);
glUniform1i(glGetUniformLocation(DeferredLighting, "ColorBuffer"), 0);
glUniform1i(glGetUniformLocation(DeferredLighting, "NormalBuffer"), 1);
glUniform1i(glGetUniformLocation(DeferredLighting, "DepthBuffer"), 2);
glUseProgram(0);
// ------------------------------------------------------------------------------------------------------------------------
glGenTextures(1, &ColorBuffer);
glGenTextures(1, &NormalBuffer);
glGenTextures(1, &DepthBuffer);
// ------------------------------------------------------------------------------------------------------------------------
glGenBuffers(1, &VBO);
InitArrayBuffers();
// ------------------------------------------------------------------------------------------------------------------------
glGenFramebuffersEXT(1, &FBO);
// ------------------------------------------------------------------------------------------------------------------------
LightColors[0] = vec3(1.0f, 0.0f, 0.0f);
LightPositions[0] = vec3(0.0f, 1.5f, 0.33f);
LightColors[1] = vec3(0.0f, 1.0f, 0.0f);
LightPositions[1] = rotate(LightPositions[0], 120.0f, vec3(0.0f, 1.0f, 0.0f));
LightColors[2] = vec3(0.0f, 0.0f, 1.0f);
LightPositions[2] = rotate(LightPositions[1], 120.0f, vec3(0.0f, 1.0f, 0.0f));
LightColors[3] = vec3(1.0f, 1.0f, 1.0f);
LightPositions[3] = vec3(0.0f, 2.75f, -4.75f);
for(int i = 0; i < 3; i++)
{
glLightfv(GL_LIGHT0 + i, GL_AMBIENT, &vec4(LightColors[i] * 0.125f, 1.0f));
glLightfv(GL_LIGHT0 + i, GL_DIFFUSE, &vec4(LightColors[i] * 0.875f, 1.0f));
glLightf(GL_LIGHT0 + i, GL_LINEAR_ATTENUATION, 1.0f);
glLightf(GL_LIGHT0 + i, GL_QUADRATIC_ATTENUATION, 1.0f);
}
glLightfv(GL_LIGHT3, GL_AMBIENT, &vec4(LightColors[3] * 0.25f, 1.0f));
glLightfv(GL_LIGHT3, GL_DIFFUSE, &vec4(LightColors[3] * 0.75f, 1.0f));
glLightf(GL_LIGHT3, GL_LINEAR_ATTENUATION, 1.0f);
glLightf(GL_LIGHT3, GL_QUADRATIC_ATTENUATION, 1.0f);
// ------------------------------------------------------------------------------------------------------------------------
Camera.Look(vec3(0.0f, 1.75f, 1.875f), vec3(0.0f, 1.5f, 0.0f));
// ------------------------------------------------------------------------------------------------------------------------
return true;
// ------------------------------------------------------------------------------------------------------------------------
}
void COpenGLRenderer::Render(float FrameTime)
{
// ------------------------------------------------------------------------------------------------------------------------
GLenum Buffers[] = {GL_COLOR_ATTACHMENT0_EXT, GL_COLOR_ATTACHMENT1_EXT};
// render scene to textures -----------------------------------------------------------------------------------------------
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, FBO);
glDrawBuffers(2, Buffers); glReadBuffer(GL_COLOR_ATTACHMENT0_EXT);
glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, ColorBuffer, 0);
glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT1_EXT, GL_TEXTURE_2D, NormalBuffer, 0);
glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_TEXTURE_2D, DepthBuffer, 0);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode(GL_MODELVIEW);
glLoadMatrixf(&ViewMatrix);
glEnable(GL_DEPTH_TEST);
glEnable(GL_CULL_FACE);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glTexCoordPointer(2, GL_FLOAT, 32, (void*)0);
glEnableClientState(GL_NORMAL_ARRAY);
glNormalPointer(GL_FLOAT, 32, (void*)8);
glEnableClientState(GL_VERTEX_ARRAY);
glVertexPointer(3, GL_FLOAT, 32, (void*)20);
glUseProgram(Preprocess);
glUniform1i(Preprocess.UniformLocations[0], true);
glColor3f(1.0f, 1.0f, 1.0f);
glBindTexture(GL_TEXTURE_2D, Texture[0]);
glDrawArrays(GL_QUADS, 0, 96);
glBindTexture(GL_TEXTURE_2D, Texture[1]);
glDrawArrays(GL_QUADS, 96, 4);
glBindTexture(GL_TEXTURE_2D, Texture[2]);
glDrawArrays(GL_QUADS, 100, 80);
glBindTexture(GL_TEXTURE_2D, 0);
glUniform1i(Preprocess.UniformLocations[0], false);
glDrawArrays(GL_QUADS, 180, 4);
glMultMatrixf(&ModelMatrix);
glColor3f(0.33f, 0.66f, 1.0f);
glDrawArrays(GL_QUADS, 184, 72);
glUseProgram(0);
glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_NORMAL_ARRAY);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glDisable(GL_CULL_FACE);
glDisable(GL_DEPTH_TEST);
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
// set lights positions ---------------------------------------------------------------------------------------------------
glMatrixMode(GL_MODELVIEW);
glLoadMatrixf(&ViewMatrix);
for(int i = 0; i < 4; i++)
{
glLightfv(GL_LIGHT0 + i, GL_POSITION, &vec4(LightPositions[i], 1.0f));
}
// calculate lighting -----------------------------------------------------------------------------------------------------
glActiveTexture(GL_TEXTURE0); glBindTexture(GL_TEXTURE_2D, ColorBuffer);
glActiveTexture(GL_TEXTURE1); glBindTexture(GL_TEXTURE_2D, NormalBuffer);
glActiveTexture(GL_TEXTURE2); glBindTexture(GL_TEXTURE_2D, DepthBuffer);
glUseProgram(DeferredLighting);
glBegin(GL_QUADS);
glVertex2f(0.0f, 0.0f);
glVertex2f(1.0f, 0.0f);
glVertex2f(1.0f, 1.0f);
glVertex2f(0.0f, 1.0f);
glEnd();
glUseProgram(0);
glActiveTexture(GL_TEXTURE2); glBindTexture(GL_TEXTURE_2D, 0);
glActiveTexture(GL_TEXTURE1); glBindTexture(GL_TEXTURE_2D, 0);
glActiveTexture(GL_TEXTURE0); glBindTexture(GL_TEXTURE_2D, 0);
// rotate object and lights -----------------------------------------------------------------------------------------------
if(!Pause)
{
static float a = 0.0f;
ModelMatrix = translate(0.0f, 1.5f, 0.0f) * rotate(a, vec3(0.0f, 1.0f, 0.0f)) * rotate(a, vec3(1.0f, 0.0f, 0.0f));
a += 22.5f * FrameTime;
for(int i = 0; i < 3; i++)
{
LightPositions[i] = rotate(LightPositions[i], -180.0f * FrameTime, vec3(0.0f, 1.0f, 0.0f));
}
}
// ------------------------------------------------------------------------------------------------------------------------
}
void COpenGLRenderer::Resize(int Width, int Height)
{
this->Width = Width;
this->Height = Height;
glViewport(0, 0, Width, Height);
ProjectionMatrix = perspective(45.0f, (float)Width / (float)Height, 0.125f, 512.0f);
glMatrixMode(GL_PROJECTION);
glLoadMatrixf(&ProjectionMatrix);
ProjectionBiasMatrixInverse = inverse(ProjectionMatrix) * BiasMatrixInverse;
glBindTexture(GL_TEXTURE_2D, ColorBuffer);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, Width, Height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
glBindTexture(GL_TEXTURE_2D, 0);
glBindTexture(GL_TEXTURE_2D, NormalBuffer);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, Width, Height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
glBindTexture(GL_TEXTURE_2D, 0);
glBindTexture(GL_TEXTURE_2D, DepthBuffer);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT24, Width, Height, 0, GL_DEPTH_COMPONENT, GL_FLOAT, NULL);
glBindTexture(GL_TEXTURE_2D, 0);
glUseProgram(DeferredLighting);
glUniformMatrix4fv(DeferredLighting.UniformLocations[0], 1, GL_FALSE, &ProjectionBiasMatrixInverse);
glUseProgram(0);
}
void COpenGLRenderer::Destroy()
{
for(int i = 0; i < 3; i++)
{
Texture[i].Destroy();
}
Preprocess.Destroy();
DeferredLighting.Destroy();
glDeleteBuffers(1, &VBO);
glDeleteTextures(1, &ColorBuffer);
glDeleteTextures(1, &NormalBuffer);
glDeleteTextures(1, &DepthBuffer);
if(GLEW_EXT_framebuffer_object)
{
glDeleteFramebuffersEXT(1, &FBO);
}
}
void COpenGLRenderer::InitArrayBuffers()
{
CBuffer buffer;
...
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, buffer.GetDataSize(), buffer.GetData(), GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
buffer.Empty();
}
...
void COpenGLView::OnKeyDown(UINT Key)
{
switch(Key)
{
case VK_SPACE:
OpenGLRenderer.Pause = !OpenGLRenderer.Pause;
break;
}
}
...
void CWnd::OnPaint()
{
...
float MinD = 0.25f;
if(Keys & 0x3F)
{
vec3 Movement = Camera.OnKeys(Keys, FrameTime);
if(Camera.Reference.x + Movement.x < -5.0f + MinD) Movement.x -= Camera.Reference.x + Movement.x - (-5.0f + MinD);
if(Camera.Reference.x + Movement.x > 5.0f - MinD) Movement.x -= Camera.Reference.x + Movement.x - ( 5.0f - MinD);
if(Camera.Reference.y + Movement.y < 0.0f + MinD) Movement.y -= Camera.Reference.y + Movement.y - ( 0.0f + MinD);
if(Camera.Reference.y + Movement.y > 3.0f - MinD) Movement.y -= Camera.Reference.y + Movement.y - ( 3.0f - MinD);
if(Camera.Reference.z + Movement.z < -5.0f + MinD) Movement.z -= Camera.Reference.z + Movement.z - (-5.0f + MinD);
if(Camera.Reference.z + Movement.z > 5.0f - MinD) Movement.z -= Camera.Reference.z + Movement.z - ( 5.0f - MinD);
Camera.Move(Movement);
}
if(GetKeyState(VK_NUMPAD4) & 0x80) OpenGLRenderer.LightPositions[3].x -= FrameTime;
if(GetKeyState(VK_NUMPAD6) & 0x80) OpenGLRenderer.LightPositions[3].x += FrameTime;
if(GetKeyState(VK_NUMPAD2) & 0x80) OpenGLRenderer.LightPositions[3].y -= FrameTime;
if(GetKeyState(VK_NUMPAD8) & 0x80) OpenGLRenderer.LightPositions[3].y += FrameTime;
if(GetKeyState(VK_NUMPAD9) & 0x80) OpenGLRenderer.LightPositions[3].z -= FrameTime;
if(GetKeyState(VK_NUMPAD1) & 0x80) OpenGLRenderer.LightPositions[3].z += FrameTime;
if(OpenGLRenderer.LightPositions[3].x < -5.0f + MinD) OpenGLRenderer.LightPositions[3].x = -5.0f + MinD;
if(OpenGLRenderer.LightPositions[3].x > 5.0f - MinD) OpenGLRenderer.LightPositions[3].x = 5.0f - MinD;
if(OpenGLRenderer.LightPositions[3].y < 0.0f + MinD) OpenGLRenderer.LightPositions[3].y = 0.0f + MinD;
if(OpenGLRenderer.LightPositions[3].y > 3.0f - MinD) OpenGLRenderer.LightPositions[3].y = 3.0f - MinD;
if(OpenGLRenderer.LightPositions[3].z < -5.0f + MinD) OpenGLRenderer.LightPositions[3].z = -5.0f + MinD;
if(OpenGLRenderer.LightPositions[3].z > 5.0f - MinD) OpenGLRenderer.LightPositions[3].z = 5.0f - MinD;
if(GetKeyState(VK_NUMPAD5) & 0x80) OpenGLRenderer.LightPositions[3] = vec3(0.0f, 2.75f, 0.0f);
...
}
...
preprocess.vs
#version 120
varying vec3 Normal;
void main()
{
gl_FrontColor = gl_Color;
gl_TexCoord[0] = gl_MultiTexCoord0;
Normal = gl_NormalMatrix * gl_Normal;
gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
}
preprocess.fs
#version 120
uniform sampler2D Texture;
uniform bool Texturing;
varying vec3 Normal;
void main()
{
gl_FragData[0] = gl_Color;
if(Texturing) gl_FragData[0] *= texture2D(Texture, gl_TexCoord[0].st);
gl_FragData[1] = vec4(normalize(Normal) * 0.5 + 0.5, 1.0);
}
deferredlighting.vs
#version 120
void main()
{
gl_TexCoord[0] = gl_Vertex;
gl_Position = gl_Vertex * 2.0 - 1.0;
}
deferredlighting.fs
#version 120
uniform sampler2D ColorBuffer, NormalBuffer, DepthBuffer;
uniform mat4x4 ProjectionBiasMatrixInverse;
void main()
{
gl_FragColor = texture2D(ColorBuffer, gl_TexCoord[0].st);
float Depth = texture2D(DepthBuffer, gl_TexCoord[0].st).r;
if(Depth < 1.0)
{
vec3 Normal = normalize(texture2D(NormalBuffer, gl_TexCoord[0].st).rgb * 2.0 - 1.0);
vec4 Position = ProjectionBiasMatrixInverse * vec4(gl_TexCoord[0].st, Depth, 1.0);
Position /= Position.w;
vec3 Light = vec3(0.0);
for(int i = 0; i < 4; i++)
{
vec3 LightDirection = gl_LightSource[i].position.xyz - Position.xyz;
float LightDistance2 = dot(LightDirection, LightDirection);
float LightDistance = sqrt(LightDistance2);
LightDirection /= LightDistance;
float NdotLD = max(dot(Normal, LightDirection), 0.0);
float Attenuation = gl_LightSource[i].constantAttenuation;
Attenuation += gl_LightSource[i].linearAttenuation * LightDistance;
Attenuation += gl_LightSource[i].quadraticAttenuation * LightDistance2;
Light += (gl_LightSource[i].ambient.rgb + gl_LightSource[i].diffuse.rgb * NdotLD) / Attenuation;
}
gl_FragColor.rgb *= Light;
}
}
Color buffer, view space normal buffer, depth buffer and final image Download
deferred_rendering_point_lights.zip (Visual Studio 2005 Professional)
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© 2010 - 2016 Bc. Michal Belanec, michalbelanec (at) centrum (dot) sk
Last update June 25, 2016 OpenGL® is a registered trademark of Silicon Graphics Inc. |