优化OpenGL片段着色器
我有一个顶点/片段着色器,它绘制一个矩形,根据纹理执行许多计算。(它混合像素、修改像素等)。问题是每个矩形及其包含的像素不会改变。我只移动整个矩形并缩放它们优化OpenGL片段着色器,opengl,shader,fragment-shader,Opengl,Shader,Fragment Shader,我有一个顶点/片段着色器,它绘制一个矩形,根据纹理执行许多计算。(它混合像素、修改像素等)。问题是每个矩形及其包含的像素不会改变。我只移动整个矩形并缩放它们 有没有办法优化片段着色器,因为矩形实际上不需要重新计算?因此,如果我理解正确,您只需计算一次这些矩形,然后想重用它们?这类任务通过渲染到纹理,然后进一步使用生成的纹理来解决 渲染到纹理最容易通过帧缓冲区对象完成 编辑:使用FBO渲染到纹理的简单示例 // test_fbo_teapot.cpp #include <GL/glew.h
有没有办法优化片段着色器,因为矩形实际上不需要重新计算?因此,如果我理解正确,您只需计算一次这些矩形,然后想重用它们?这类任务通过渲染到纹理,然后进一步使用生成的纹理来解决 渲染到纹理最容易通过帧缓冲区对象完成 编辑:使用FBO渲染到纹理的简单示例
// test_fbo_teapot.cpp
#include <GL/glew.h> // Uses GLEW for extension loading
#include <GL/glut.h> // Uses GLUT as framework
// Check those are on your system for compilation
// and if not please install them.
#include <cmath>
#include <iostream>
using namespace std;
namespace render
{
int width, height;
float aspect;
void init();
void reshape(int width, int height);
void display();
int const fbo_width = 512;
int const fbo_height = 512;
GLuint fb, color, depth;
};
void idle();
int main(int argc, char *argv[])
{
glutInit(&argc, argv);
glutInitDisplayMode( GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH );
glutCreateWindow("FBO test");
glutDisplayFunc(render::display);
glutReshapeFunc(render::reshape);
glutIdleFunc(idle);
glewInit();
render::init();
glutMainLoop();
return 0;
}
void idle()
{
glutPostRedisplay();
}
void CHECK_FRAMEBUFFER_STATUS()
{
GLenum status;
status = glCheckFramebufferStatus(GL_DRAW_FRAMEBUFFER);
switch(status) {
case GL_FRAMEBUFFER_COMPLETE:
break;
case GL_FRAMEBUFFER_UNSUPPORTED:
/* choose different formats */
break;
default:
/* programming error; will fail on all hardware */
throw "Framebuffer Error";
}
}
namespace render
{
float const light_dir[]={1,1,1,0};
float const light_color[]={1,0.95,0.9,1};
void init()
{
glGenFramebuffers(1, &fb);
glGenTextures(1, &color);
glGenRenderbuffers(1, &depth);
glBindFramebuffer(GL_DRAW_FRAMEBUFFER, fb);
glBindTexture(GL_TEXTURE_2D, color);
glTexImage2D( GL_TEXTURE_2D,
0,
GL_RGBA,
fbo_width, fbo_height,
0,
GL_RGBA,
GL_UNSIGNED_BYTE,
NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, color, 0);
glBindRenderbuffer(GL_RENDERBUFFER, depth);
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, fbo_width, fbo_height);
glFramebufferRenderbuffer(GL_DRAW_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depth);
CHECK_FRAMEBUFFER_STATUS();
}
void reshape(int width, int height)
{
render::width=width;
render::height=height;
aspect=float(width)/float(height);
glutPostRedisplay();
}
void prepare()
{
static float a=0, b=0, c=0;
glBindTexture(GL_TEXTURE_2D, 0);
glEnable(GL_TEXTURE_2D);
glBindFramebuffer(GL_DRAW_FRAMEBUFFER, fb);
glViewport(0,0,fbo_width, fbo_height);
glClearColor(1,1,1,0);
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45, 1, 1, 10);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glEnable(GL_LIGHT0);
glEnable(GL_LIGHTING);
glEnable(GL_DEPTH_TEST);
glDisable(GL_CULL_FACE);
glLightfv(GL_LIGHT0, GL_POSITION, light_dir);
glLightfv(GL_LIGHT0, GL_DIFFUSE, light_color);
glTranslatef(0,0,-5);
glRotatef(a, 1, 0, 0);
glRotatef(b, 0, 1, 0);
glRotatef(c, 0, 0, 1);
glutSolidTeapot(0.75);
a=fmod(a+0.1, 360.);
b=fmod(b+0.5, 360.);
c=fmod(c+0.25, 360.);
}
void intermediary()
{
}
void final()
{
static float a=0, b=0, c=0;
glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
glViewport(0,0, width, height);
glClearColor(1,1,1,1);
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45, aspect, 1, 10);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0,0,-5);
glRotatef(b, 0, 1, 0);
b=fmod(b+0.5, 360.);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, color);
glEnable(GL_DEPTH_TEST);
glEnable(GL_CULL_FACE);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glDisable(GL_LIGHTING);
float cube[][5]=
{
{-1, -1, -1, 0, 0},
{ 1, -1, -1, 1, 0},
{ 1, 1, -1, 1, 1},
{-1, 1, -1, 0, 1},
{-1, -1, 1, -1, 0},
{ 1, -1, 1, 0, 0},
{ 1, 1, 1, 0, 1},
{-1, 1, 1, -1, 1},
};
unsigned int faces[]=
{
0, 1, 2, 3,
1, 5, 6, 2,
5, 4, 7, 6,
4, 0, 3, 7,
3, 2, 6, 7,
4, 5, 1, 0
};
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glVertexPointer(3, GL_FLOAT, 5*sizeof(float), &cube[0][0]);
glTexCoordPointer(2, GL_FLOAT, 5*sizeof(float), &cube[0][3]);
glCullFace(GL_BACK);
glDrawElements(GL_QUADS, 24, GL_UNSIGNED_INT, faces);
glCullFace(GL_FRONT);
glDrawElements(GL_QUADS, 24, GL_UNSIGNED_INT, faces);
glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
}
void display()
{
prepare();
intermediary();
final();
glutSwapBuffers();
}
};
//test\u fbo\u teapot.cpp
#include//使用GLEW加载扩展
#include//使用GLUT作为框架
//检查您的系统上是否有用于编译的文件
//如果没有,请安装它们。
#包括
#包括
使用名称空间std;
命名空间呈现
{
int宽度、高度;
浮动方面;
void init();
空洞重塑(内部宽度、内部高度);
void display();
int const fbo_width=512;
int const fbo_height=512;
胶水,颜色,深度;
};
无效空闲();
int main(int argc,char*argv[])
{
glutInit(&argc,argv);
glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_深度);
玻璃窗(“FBO测试”);
glutDisplayFunc(渲染::显示);
GLUTREFORMATEFUNC(渲染::重塑);
glutIdleFunc(空闲);
glewInit();
render::init();
glutMainLoop();
返回0;
}
无效空闲()
{
再发现();
}
无效检查\u帧缓冲区\u状态()
{
盂状态;
状态=glCheckFramebufferStatus(GL\u DRAW\u FRAMEBUFFER);
开关(状态){
案例GL\u帧缓冲区\u完成:
打破
不支持案例GL\u帧缓冲区\u:
/*选择不同的格式*/
打破
违约:
/*编程错误;将在所有硬件上失败*/
抛出“帧缓冲区错误”;
}
}
命名空间呈现
{
float const light_dir[]={1,1,1,0};
float const light_color[]={1,0.95,0.9,1};
void init()
{
glGenFramebuffers(1和fb);
glGenTextures(1,彩色);
glGenRenderbuffers(1和深度);
glBindFramebuffer(GL_DRAW_FRAMEBUFFER,fb);
glBindTexture(GL_纹理_2D,颜色);
glTexImage2D(GL_纹理_2D,
0,
格尔巴,
fbo_宽度,fbo_高度,
0,
格尔巴,
GL_无符号字节,
无效);
glTexParameteri(GL_纹理2D、GL_纹理最小过滤器、GL_线性);
glTexParameteri(GL_纹理2D、GL_纹理MAG_过滤器、GL_线性);
glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER,GL_COLOR_ATTACHMENT0,GL_TEXTURE_2D,COLOR,0);
glBindRenderbuffer(GLU RENDERBUFFER,深度);
GLRENDERBUFFER存储(GLRENDERBUFFER,GLRENDERBUFFER深度组件24,fbo宽度,fbo高度);
glFramebufferRenderbuffer(GL_DRAW_FRAMEBUFFER,GL_DEPTH_附件,GL_RENDERBUFFER,DEPTH);
检查_帧缓冲区_状态();
}
空洞重塑(整型宽度、整型高度)
{
渲染::宽度=宽度;
渲染::高度=高度;
纵横比=浮动(宽度)/浮动(高度);
再发现();
}
无效准备()
{
静态浮动a=0,b=0,c=0;
glBindTexture(GL_TEXTURE_2D,0);
glEnable(GL_纹理_2D);
glBindFramebuffer(GL_DRAW_FRAMEBUFFER,fb);
glViewport(0,0,fbo_宽度,fbo_高度);
glClearColor(1,1,1,0);
glClear(GL_颜色_缓冲_位| GL_深度_缓冲_位);
glMatrixMode(GL_投影);
glLoadIdentity();
GLU透视图(45,1,1,10);
glMatrixMode(GLU模型视图);
glLoadIdentity();
glEnable(GL_LIGHT0);
glEnable(德国劳埃德大学照明);
glEnable(GLU深度试验);
glDisable(GLU消隐面);
glLightfv(GL_LIGHT0,GL_位置,light_dir);
glLightfv(GL_LIGHT0,GL_漫反射,light_color);
glTranslatef(0,0,-5);
glRotatef(a,1,0,0);
glRotatef(b,0,1,0);
glRotatef(c,0,0,1);
茶壶(0.75);
a=fmod(a+0.1360.);
b=fmod(b+0.5360);
c=fmod(c+0.25360);
}
无效中介人()
{
}
最终作废()
{
静态浮动a=0,b=0,c=0;
glBindFramebuffer(GL\u DRAW\u FRAMEBUFFER,0);
glViewport(0,0,宽度,高度);
glClearColor(1,1,1,1);
glClear(GL_颜色_缓冲_位| GL_深度_缓冲_位);
glMatrixMode(GL_投影);
glLoadIdentity();
透视图(45,纵横比,1,10);
glMatrixMode(GLU模型视图);
glLoadIdentity();
glTranslatef(0,0,-5);
glRotatef(b,0,1,0);
b=fmod(b+0.5360);
glEnable(GL_纹理_2D);
glBindTexture(GL_纹理_2D,颜色);
glEnable(GLU深度试验);
glEnable(GL_CULL_面);
glEnable(GL_混合物);
glBlendFunc(GL_SRC_ALPHA,GL_ONE_减去GL_SRC_ALPHA);
glDisable(GLU照明);
浮动立方体[][5]=
{
{-1, -1, -1, 0, 0},
{ 1, -1, -1, 1, 0},
{ 1, 1, -1, 1, 1},
{-1, 1, -1, 0, 1},
{-1, -1, 1, -1, 0},
{ 1, -1, 1, 0, 0},
{ 1, 1, 1, 0, 1},
{-1, 1, 1, -1, 1},
};
无符号整数面[]=
{
0, 1, 2, 3,
1, 5, 6, 2,
5, 4, 7, 6,
4, 0, 3, 7,
3, 2, 6, 7,
4, 5, 1, 0
};
glEnableClientState(GL_顶点_数组);
glEnableClientState(GL_纹理_坐标_阵列);
glvertexointer(3,GL_FLOAT,5*sizeof(FLOAT),&cube[0][0]);
glTexCoordPointer(2,GL_FLOAT,5*sizeof(FLOAT),&cube[0][3]);
正面(背面);
GLD元件(GLU四边形,24,GL_