OpenGL - OBJ 中的顶点法线
OpenGL - vertex normals in OBJ
我想知道如何使用顶点法线来实现闪电效果？目前我所拥有的是我可以将顶点和纹理坐标发送到着色器并使用它们但是对于法线，我不知道如何在着色器程序中使用它们。以下是我目前所拥有的。
// vertex shader
layout(location = 0) in vec4 vert;
layout(location = 1) in vec4 color;
layout(location = 2) in vec2 texcoord;
uniform mat4 m_model;
uniform mat4 m_view;
uniform mat4 m_proj;
void main() {
gl_Position = m_proj * m_view * m_model * vert;
}
// fragment shader
in vec2 fragtexcoord;
out vec4 color;
uniform sampler2D textureunit;
void main(void) {
color = texture(textureunit, fragtexcoord);
}
编辑
这是我现在的着色器。
顶点着色器
layout(location = 0) in vec4 vert;
layout(location = 1) in vec4 color;
layout(location = 2) in vec2 texcoord;
layout(location = 3) in vec4 normal;
out vec4 LightIntensity;
uniform vec4 LightPosition;
uniform vec4 Kd;
uniform vec4 Ld;
uniform mat4 m_model;
uniform mat4 m_view;
uniform mat4 m_proj;
void main() {
gl_Position = m_proj * m_view * m_model * vert;
mat4 normalmatrix = transpose(inverse(m_view));
vec4 tnorm = normalize(normalmatrix * normal);
vec4 eyeCoords = m_model * vec4(vert);
vec4 s = normalize(vec4(LightPosition - eyeCoords));
LightIntensity = Ld * Kd * max(dot(s, tnorm), 0.0);
}
片段着色器。
in vec4 LightIntensity;
out vec4 color;
void main(void) {
color = vec4(LightIntensity);
}
目前得到一个没有阴影的黑色立方体。可能我在着色器中做错了什么，我不知道是哪一个 :(
更新：
顶点
layout(location = 0) in vec4 vert;
layout(location = 1) in vec4 color;
layout(location = 2) in vec2 texcoord;
layout(location = 3) in vec4 normal;
out vec2 fragtexcoord;
out vec4 fragnormal;
uniform mat4 m_model;
uniform mat4 m_view;
uniform mat4 m_proj;
void main() {
gl_Position = m_proj * m_view * m_model * vert;
fragtexcoord = texcoord;
fragnormal = normal;
}
片段
in vec2 fragtexcoord;
in vec4 fragnormal;
out vec4 fragment_color;
uniform sampler2D textureunit;
void main(void) {
vec4 lt_ambient = vec4(0.2, 0.2, 0.2, 1.0);
vec4 lt_direct = vec4(0.8, 0.8, 0.8, 1.0);
vec4 lt_direct_dir = vec4(1.5, 1.0, 1.0, 1.0);
vec4 color = texture(textureunit, fragtexcoord);
fragment_color = (lt_ambient + (lt_direct * dot(lt_direct_dir, -fragnormal))) * color;
}
我不知道要为 lt_direct_dir 添加什么，这就是为什么它具有这样的值:)
更新：下面是我的工作着色器
// vertex shader
layout(location = 0) in vec4 vert;
layout(location = 1) in vec4 color;
layout(location = 2) in vec2 texcoord;
layout(location = 3) in vec4 normal;
out vec4 fragposition;
out vec4 fragcolor;
out vec4 fragnormal;
out vec2 fragtexcoord;
uniform mat4 m_model;
uniform mat4 m_view;
uniform mat4 m_proj;
uniform vec4 lightpos;
void main() {
gl_Position = m_proj * m_view * m_model * vert;
mat4 m_normal = transpose(inverse(m_model));
fragposition = m_model * vert;
fragnormal = m_normal * normal;
fragtexcoord = texcoord;
}
// fragment shader
in vec4 fragposition;
in vec4 fragnormal;
in vec2 fragtexcoord;
out vec4 fragment_color;
uniform sampler2D textureunit;
void main() {
vec4 lt_pnt_pos = vec4(2.5, 2.5, 2.5, 1.0);
vec4 lt_pnt_col = vec4(0.8, 0.8, 0.8, 1.0);
vec4 lt_amb_col = vec4(0.2, 0.2, 0.2, 1.0);
vec4 lt_dir = normalize(lt_pnt_pos - fragposition);
float li = dot(fragnormal, lt_dir);
if(li < 0.0) {
li = 0.0;
}
vec4 color = texture(textureunit, fragtexcoord);
fragment_color = color * (lt_amb_col + (lt_pnt_col * li));
}
normal/bump 地图
在不增加几何复杂性的情况下提供精细的细节，这意味着以极低的性能成本提供更多细节。 Normal/bump 地图是粗糙的可选。
普通着色（片段着色器）
法线是垂直于 fragment/face/primitive 的向量，它有 2 个用途：
- 暗淡的表面照明
让我们有：
color - 每个 fragment/face/primitive 颜色（用纹理调制）normal - 每个 fragment/face/primitive 3D 法向量（指向网格外）lt_ambient,lt_direct - 灯光颜色和强度lt_direct_dir - 定向光方向
那么输出就简单了：
fragment_color=(lt_ambient+(lt_direct*dot(lt_direct_dir,-normal))*color;
这称为正常着色
dot returns cos(angle between light and normal) 如果你想要摊位侧面的几何形状，那么使用 fabs(dot(...))。加在一起的光色和强度矢量不应超过每个通道 1.0，否则夹紧可能会导致颜色伪影。使用例如：
lt_ambient=(0.2,0.2,0.2)lt_direct =(0.8,0.8,0.8)
as lt_direct_dir 您可以使用 (fragment_xyz-Sun.xyz) 并归一化为单位向量或使用相机视角方向。 点积需要单位向量，否则无法正常工作
- 反射
如果您有任何环境贴图 (cube_map)，那么您可以添加倒影。你得到了片段 (x,y,z) 坐标和 normal 所以你可以计算反射观察方向的方向并添加它指向结果的纹素 fragment_color.
还有更多的东西，比如镜面高光和不同的光方程，但我认为你应该先从法线着色开始。当你掌握了基础知识，那么理解更高级的东西就没问题了，只要永远记住背后的东西......
[edit1] 既然你是新手，那么你显然需要完整的例子来开始：
所以这里用 C++ 完成了 GL+VAO/VBO+GLSL+shaders 的例子。当我使用 Borland 环境时，它是 VCL 形式的应用程序，因此只需忽略 VCL 内容并仅提取您需要的内容。这是它的样子：
那个十字是我用来目视检查正确性的点光源位置，那个箭头（手绘）显示的是平均光线方向。
normal_shading.glsl_vert
// Vertex
#version 400 core
layout(location = 0) in vec3 pos;
layout(location = 2) in vec3 nor;
layout(location = 3) in vec3 col;
uniform mat4 m_model; // model matrix
uniform mat4 m_normal; // model matrix with origin=(0,0,0)
uniform mat4 m_view; // inverse of camera matrix
uniform mat4 m_proj; // projection matrix
out vec3 pixel_pos; // fragment position [GCS]
out vec3 pixel_col; // fragment surface color
out vec3 pixel_nor; // fragment surface normal [GCS]
void main()
{
pixel_col=col;
pixel_pos=(m_model*vec4(pos,1)).xyz;
pixel_nor=(m_normal*vec4(nor,1)).xyz;
gl_Position=m_proj*m_view*m_model*vec4(pos,1);
}
normal_shading.glsl_frag
// Fragment
#version 400 core
uniform vec3 lt_pnt_pos;// point light source position [GCS]
uniform vec3 lt_pnt_col;// point light source color&strength
uniform vec3 lt_amb_col;// ambient light source color&strength
in vec3 pixel_pos; // fragment position [GCS]
in vec3 pixel_col; // fragment surface color
in vec3 pixel_nor; // fragment surface normal [GCS]
out vec4 col;
void main()
{
float li;
vec3 c,lt_dir;
lt_dir=normalize(lt_pnt_pos-pixel_pos); // vector from fragment to point light source in [GCS]
li=dot(pixel_nor,lt_dir);
if (li<0.0) li=0.0;
c=pixel_col*(lt_amb_col+(lt_pnt_col*li));
col=vec4(c,1.0);
}
gl_simple.h
//---------------------------------------------------------------------------
//--- GL simple ver: 1.000 --------------------------------------------------
//---------------------------------------------------------------------------
#define GLEW_STATIC
#include "glew.c"
#include <gl\gl.h>
#include <gl\glu.h>
//---------------------------------------------------------------------------
//--- OpenGL GL example -----------------------------------------------------
//---------------------------------------------------------------------------
int xs,ys; // screen size
HDC hdc=NULL; // device context
HGLRC hrc=NULL; // rendering context
int gl_inicialized=0;
int gl_init(HWND Handle);
void gl_exit();
void gl_draw();
void gl_resize(int _xs,int _ys);
//---------------------------------------------------------------------------
//--- OpenGL GLSL example ---------------------------------------------------
//---------------------------------------------------------------------------
GLint prog_id=0, // whole program
vert_id=0, // vertex shader
frag_id=0; // fragment shader
char glsl_log[4096];// compile/link GLSL log
int glsl_logs=0;
void glsl_init(char *vert,char *frag); // create/compile/link GLSL program
void glsl_exit();
//---------------------------------------------------------------------------
//--- OpenGL VAO example ----------------------------------------------------
//---------------------------------------------------------------------------
#pragma pack(1)
//#define vao_indices
GLuint vbo[4]={-1,-1,-1,-1};
GLuint vao[4]={-1,-1,-1,-1};
const GLfloat vao_pos[]=
{
// x y z //ix
-1.0,+1.0,-1.0, //0
+1.0,+1.0,-1.0, //1
+1.0,-1.0,-1.0, //2
-1.0,-1.0,-1.0, //3
-1.0,-1.0,+1.0, //4
+1.0,-1.0,+1.0, //5
+1.0,+1.0,+1.0, //6
-1.0,+1.0,+1.0, //7
#ifndef vao_indices
-1.0,-1.0,-1.0, //3
+1.0,-1.0,-1.0, //2
+1.0,-1.0,+1.0, //5
-1.0,-1.0,+1.0, //4
+1.0,-1.0,-1.0, //2
+1.0,+1.0,-1.0, //1
+1.0,+1.0,+1.0, //6
+1.0,-1.0,+1.0, //5
+1.0,+1.0,-1.0, //1
-1.0,+1.0,-1.0, //0
-1.0,+1.0,+1.0, //7
+1.0,+1.0,+1.0, //6
-1.0,+1.0,-1.0, //0
-1.0,-1.0,-1.0, //3
-1.0,-1.0,+1.0, //4
-1.0,+1.0,+1.0, //7
#endif
};
const GLfloat vao_col[]=
{
// r g b //ix
0.0,0.0,0.0, //0
1.0,0.0,0.0, //1
1.0,1.0,0.0, //2
0.0,1.0,0.0, //3
0.0,0.0,1.0, //4
1.0,0.0,1.0, //5
1.0,1.0,1.0, //6
0.0,1.0,1.0, //7
#ifndef vao_indices
0.0,0.0,0.0, //0
1.0,0.0,0.0, //1
1.0,0.0,1.0, //5
0.0,0.0,1.0, //4
1.0,0.0,0.0, //1
1.0,1.0,0.0, //2
1.0,1.0,1.0, //6
1.0,0.0,1.0, //5
1.0,1.0,0.0, //2
0.0,1.0,0.0, //3
0.0,1.0,1.0, //7
1.0,1.0,1.0, //6
0.0,1.0,0.0, //3
0.0,0.0,0.0, //0
0.0,0.0,1.0, //4
0.0,1.0,1.0, //7
#endif
};
#ifndef vao_indices
const GLfloat vao_nor[]=
{
// nx ny nz //ix
0.0, 0.0,-1.0, //0
0.0, 0.0,-1.0, //1
0.0, 0.0,-1.0, //2
0.0, 0.0,-1.0, //3
0.0, 0.0,+1.0, //4
0.0, 0.0,+1.0, //5
0.0, 0.0,+1.0, //6
0.0, 0.0,+1.0, //7
0.0,-1.0, 0.0, //0
0.0,-1.0, 0.0, //1
0.0,-1.0, 0.0, //5
0.0,-1.0, 0.0, //4
+1.0, 0.0, 0.0, //1
+1.0, 0.0, 0.0, //2
+1.0, 0.0, 0.0, //6
+1.0, 0.0, 0.0, //5
0.0,+1.0, 0.0, //2
0.0,+1.0, 0.0, //3
0.0,+1.0, 0.0, //7
0.0,+1.0, 0.0, //6
-1.0, 0.0, 0.0, //3
-1.0, 0.0, 0.0, //0
-1.0, 0.0, 0.0, //4
-1.0, 0.0, 0.0, //7
};
#endif
#ifdef vao_indices
const GLuint vao_ix[]=
{
0,1,2,3,
4,5,6,7,
3,2,5,4,
2,1,6,5,
1,0,7,6,
0,3,4,7,
};
#endif
#pragma pack()
void vao_init();
void vao_exit();
void vao_draw();
//---------------------------------------------------------------------------
//--- bodies: ---------------------------------------------------------------
//---------------------------------------------------------------------------
int gl_init(HWND Handle)
{
if (gl_inicialized) return 1;
hdc = GetDC(Handle); // get device context
PIXELFORMATDESCRIPTOR pfd;
ZeroMemory( &pfd, sizeof( pfd ) ); // set the pixel format for the DC
pfd.nSize = sizeof( pfd );
pfd.nVersion = 1;
pfd.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
pfd.iPixelType = PFD_TYPE_RGBA;
pfd.cColorBits = 24;
pfd.cDepthBits = 24;
pfd.iLayerType = PFD_MAIN_PLANE;
SetPixelFormat(hdc,ChoosePixelFormat(hdc, &pfd),&pfd);
hrc = wglCreateContext(hdc); // create current rendering context
if(hrc == NULL)
{
ShowMessage("Could not initialize OpenGL Rendering context !!!");
gl_inicialized=0;
return 0;
}
if(wglMakeCurrent(hdc, hrc) == false)
{
ShowMessage("Could not make current OpenGL Rendering context !!!");
wglDeleteContext(hrc); // destroy rendering context
gl_inicialized=0;
return 0;
}
gl_resize(1,1);
glEnable(GL_DEPTH_TEST); // Zbuf
glDisable(GL_CULL_FACE); // vynechavaj odvratene steny
glDisable(GL_TEXTURE_2D); // pouzivaj textury, farbu pouzivaj z textury
glDisable(GL_BLEND); // priehladnost
glShadeModel(GL_SMOOTH); // gourard shading
glClearColor(0.0f, 0.0f, 0.0f, 1.0f); // background color
gl_inicialized=1;
glewInit();
return 1;
}
//---------------------------------------------------------------------------
void gl_exit()
{
if (!gl_inicialized) return;
wglMakeCurrent(NULL, NULL); // release current rendering context
wglDeleteContext(hrc); // destroy rendering context
gl_inicialized=0;
}
//---------------------------------------------------------------------------
void gl_resize(int _xs,int _ys)
{
xs=_xs;
ys=_ys;
if (xs<=0) xs = 1; // Prevent a divide by zero
if (ys<=0) ys = 1;
if (!gl_inicialized) return;
glViewport(0,0,xs,ys); // Set Viewport to window dimensions
glMatrixMode(GL_PROJECTION); // operacie s projekcnou maticou
glLoadIdentity(); // jednotkova matica projekcie
gluPerspective(30,float(xs)/float(ys),0.1,100.0); // matica=perspektiva,120 stupnov premieta z viewsize do 0.1
glMatrixMode(GL_TEXTURE); // operacie s texturovou maticou
glLoadIdentity(); // jednotkova matica textury
glMatrixMode(GL_MODELVIEW); // operacie s modelovou maticou
glLoadIdentity(); // jednotkova matica modelu (objektu)
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
void glsl_init(char *vert,char *frag)
{
const int _size=1024;
GLint status,siz=0,i;
const char * VS = vert;
const char * FS = frag;
glsl_logs=0;
if (prog_id<=0) prog_id=glCreateProgram();
if (vert_id<=0) vert_id=glCreateShader(GL_VERTEX_SHADER); else glDetachShader(prog_id,vert_id);
if (vert)
{
glShaderSource(vert_id, 1, &VS,NULL);
glCompileShader(vert_id);
glAttachShader(prog_id,vert_id);
glGetShaderiv(vert_id,GL_COMPILE_STATUS,&status);
const char t[]="[Vertex]\r\n"; for (i=0;t[i];i++) { glsl_log[glsl_logs]=t[i]; glsl_logs++; }
glGetShaderInfoLog(vert_id,_size,&siz,glsl_log+glsl_logs);
glsl_logs+=siz;
}
if (frag_id<=0) frag_id=glCreateShader(GL_FRAGMENT_SHADER); else glDetachShader(prog_id,frag_id);
if (frag)
{
glShaderSource(frag_id, 1, &FS,NULL);
glCompileShader(frag_id);
glAttachShader(prog_id,frag_id);
glGetShaderiv(frag_id,GL_COMPILE_STATUS,&status);
const char t[]="[Fragment]\r\n"; for (i=0;t[i];i++) { glsl_log[glsl_logs]=t[i]; glsl_logs++; }
glGetShaderInfoLog(frag_id,_size,&siz,glsl_log+glsl_logs);
glsl_logs+=siz;
}
glLinkProgram(prog_id);
glGetProgramiv(prog_id,GL_LINK_STATUS,&status);
const char t[]="[Program]\r\n"; for (i=0;t[i];i++) { glsl_log[glsl_logs]=t[i]; glsl_logs++; }
glGetProgramInfoLog(prog_id,_size,&siz,glsl_log+glsl_logs);
glsl_logs+=siz;
glReleaseShaderCompiler();
glsl_log[glsl_logs]=0;
}
//------------------------------------------------------------------------------
void glsl_exit()
{
glUseProgram(0);
if (vert_id>0) { glDetachShader(prog_id,vert_id); glDeleteShader(vert_id); }
if (frag_id>0) { glDetachShader(prog_id,frag_id); glDeleteShader(frag_id); }
if (prog_id>0) { glDeleteShader(prog_id); }
glsl_log[0]=0;
}
//---------------------------------------------------------------------------
//------------------------------------------------------------------------------
void vao_init()
{
GLuint i;
glGenVertexArrays(4,vao);
glGenBuffers(4,vbo);
glBindVertexArray(vao[0]);
i=0; // vertex
glBindBuffer(GL_ARRAY_BUFFER,vbo[i]);
glBufferData(GL_ARRAY_BUFFER,sizeof(vao_pos),vao_pos,GL_STATIC_DRAW);
glEnableVertexAttribArray(i);
glVertexAttribPointer(i,3,GL_FLOAT,GL_FALSE,0,0);
i=1; // indices
#ifdef vao_indices
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,vbo[i]);
glBufferData(GL_ELEMENT_ARRAY_BUFFER,sizeof(vao_ix),vao_ix,GL_STATIC_DRAW);
glEnableVertexAttribArray(i);
glVertexAttribIPointer(i,4,GL_UNSIGNED_INT,0,0);
#endif
i=2; // normal
#ifndef vao_indices
glBindBuffer(GL_ARRAY_BUFFER,vbo[i]);
glBufferData(GL_ARRAY_BUFFER,sizeof(vao_nor),vao_nor,GL_STATIC_DRAW);
glEnableVertexAttribArray(i);
glVertexAttribPointer(i,3,GL_FLOAT,GL_FALSE,0,0);
#endif
i=3; // color
glBindBuffer(GL_ARRAY_BUFFER,vbo[i]);
glBufferData(GL_ARRAY_BUFFER,sizeof(vao_col),vao_col,GL_STATIC_DRAW);
glEnableVertexAttribArray(i);
glVertexAttribPointer(i,3,GL_FLOAT,GL_FALSE,0,0);
glBindVertexArray(0);
glBindBuffer(GL_ARRAY_BUFFER,0);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,0);
glDisableVertexAttribArray(0);
glDisableVertexAttribArray(1);
glDisableVertexAttribArray(2);
glDisableVertexAttribArray(3);
}
//---------------------------------------------------------------------------
void vao_exit()
{
glDeleteVertexArrays(4,vao);
glDeleteBuffers(4,vbo);
}
//---------------------------------------------------------------------------
void vao_draw()
{
glBindVertexArray(vao[0]);
#ifndef vao_indices
glDrawArrays(GL_QUADS,0,sizeof(vao_pos)/sizeof(vao_pos[0])); // QUADS ... no indices
#endif
#ifdef vao_indices
glDrawElements(GL_QUADS,sizeof(vao_ix)/sizeof(vao_ix[0]),GL_UNSIGNED_INT,0); // indices (choose just one line not both !!!)
#endif
glBindVertexArray(0);
}
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
VCL App主窗体来源：
//---------------------------------------------------------------------------
#include <vcl.h>
#pragma hdrstop
#include "Unit1.h"
#include "gl_simple.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
//---------------------------------------------------------------------------
GLfloat lt_pnt_pos[3]={+2.5,+2.5,+2.5};
GLfloat lt_pnt_col[3]={0.8,0.8,0.8};
GLfloat lt_amb_col[3]={0.2,0.2,0.2};
//---------------------------------------------------------------------------
void gl_draw()
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// load values into shader
GLint i,id;
GLfloat m[16];
glUseProgram(prog_id);
id=glGetUniformLocation(prog_id,"lt_pnt_pos"); glUniform3fv(id,1,lt_pnt_pos);
id=glGetUniformLocation(prog_id,"lt_pnt_col"); glUniform3fv(id,1,lt_pnt_col);
id=glGetUniformLocation(prog_id,"lt_amb_col"); glUniform3fv(id,1,lt_amb_col);
glGetFloatv(GL_MODELVIEW_MATRIX,m);
id=glGetUniformLocation(prog_id,"m_model" ); glUniformMatrix4fv(id,1,GL_FALSE,m);
m[12]=0.0; m[13]=0.0; m[14]=0.0;
id=glGetUniformLocation(prog_id,"m_normal" ); glUniformMatrix4fv(id,1,GL_FALSE,m);
for (i=0;i<16;i++) m[i]=0.0; m[0]=1.0; m[5]=1.0; m[10]=1.0; m[15]=1.0;
id=glGetUniformLocation(prog_id,"m_view" ); glUniformMatrix4fv(id,1,GL_FALSE,m);
glGetFloatv(GL_PROJECTION_MATRIX,m);
id=glGetUniformLocation(prog_id,"m_proj" ); glUniformMatrix4fv(id,1,GL_FALSE,m);
// draw VAO cube
vao_draw();
// turn of shader
glUseProgram(0);
// rotate the cube to see animation
glMatrixMode(GL_MODELVIEW);
glRotatef(1.0,0.0,1.0,0.0);
glRotatef(1.0,1.0,0.0,0.0);
// render point light source in [GCS]
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadIdentity();
GLfloat x,y,z,d=0.25;
x=lt_pnt_pos[0];
y=lt_pnt_pos[1];
z=lt_pnt_pos[2];
glBegin(GL_LINES);
glColor3fv(lt_pnt_col);
glVertex3f(x-d,y,z);
glVertex3f(x+d,y,z);
glVertex3f(x,y-d,z);
glVertex3f(x,y+d,z);
glVertex3f(x,y,z-d);
glVertex3f(x,y,z+d);
glEnd();
glMatrixMode(GL_MODELVIEW);
glPopMatrix();
glFlush();
SwapBuffers(hdc);
}
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner):TForm(Owner)
{
gl_init(Handle);
int hnd,siz; char vertex[4096],fragment[4096];
hnd=FileOpen("normal_shading.glsl_vert",fmOpenRead); siz=FileSeek(hnd,0,2); FileSeek(hnd,0,0); FileRead(hnd,vertex ,siz); vertex [siz]=0; FileClose(hnd);
hnd=FileOpen("normal_shading.glsl_frag",fmOpenRead); siz=FileSeek(hnd,0,2); FileSeek(hnd,0,0); FileRead(hnd,fragment,siz); fragment[siz]=0; FileClose(hnd);
glsl_init(vertex,fragment);
hnd=FileCreate("GLSL.txt"); FileWrite(hnd,glsl_log,glsl_logs); FileClose(hnd);
vao_init();
}
//---------------------------------------------------------------------------
void __fastcall TForm1::FormDestroy(TObject *Sender)
{
gl_exit();
glsl_exit();
vao_exit();
}
//---------------------------------------------------------------------------
void __fastcall TForm1::FormResize(TObject *Sender)
{
gl_resize(ClientWidth,ClientHeight);
glMatrixMode(GL_PROJECTION);
glTranslatef(0,0,-15.0);
}
//---------------------------------------------------------------------------
void __fastcall TForm1::FormPaint(TObject *Sender)
{
gl_draw();
}
//---------------------------------------------------------------------------
void __fastcall TForm1::Timer1Timer(TObject *Sender)
{
gl_draw();
}
//---------------------------------------------------------------------------
void __fastcall TForm1::FormMouseWheel(TObject *Sender, TShiftState Shift, int WheelDelta, TPoint &MousePos, bool &Handled)
{
GLfloat dz=2.0;
if (WheelDelta<0) dz=-dz;
glMatrixMode(GL_PROJECTION);
glTranslatef(0,0,dz);
gl_draw();
}
//---------------------------------------------------------------------------
不要忘记将布局更改为您的布局，仅当这已经有效时才添加纹理和内容，并始终检查 GLSL.txt（compile/link 日志）文件以查看是否一切正常.
你还需要 GLEW 所以请看
- GLEW sourceforge
- Building glew on windows with mingw32
这是带有纹理图集的相同示例：
- Texturing a cube with different images using OpenGL
我想知道如何使用顶点法线来实现闪电效果？目前我所拥有的是我可以将顶点和纹理坐标发送到着色器并使用它们但是对于法线，我不知道如何在着色器程序中使用它们。以下是我目前所拥有的。
// vertex shader
layout(location = 0) in vec4 vert;
layout(location = 1) in vec4 color;
layout(location = 2) in vec2 texcoord;
uniform mat4 m_model;
uniform mat4 m_view;
uniform mat4 m_proj;
void main() {
gl_Position = m_proj * m_view * m_model * vert;
}
// fragment shader
in vec2 fragtexcoord;
out vec4 color;
uniform sampler2D textureunit;
void main(void) {
color = texture(textureunit, fragtexcoord);
}
编辑 这是我现在的着色器。
顶点着色器
layout(location = 0) in vec4 vert;
layout(location = 1) in vec4 color;
layout(location = 2) in vec2 texcoord;
layout(location = 3) in vec4 normal;
out vec4 LightIntensity;
uniform vec4 LightPosition;
uniform vec4 Kd;
uniform vec4 Ld;
uniform mat4 m_model;
uniform mat4 m_view;
uniform mat4 m_proj;
void main() {
gl_Position = m_proj * m_view * m_model * vert;
mat4 normalmatrix = transpose(inverse(m_view));
vec4 tnorm = normalize(normalmatrix * normal);
vec4 eyeCoords = m_model * vec4(vert);
vec4 s = normalize(vec4(LightPosition - eyeCoords));
LightIntensity = Ld * Kd * max(dot(s, tnorm), 0.0);
}
片段着色器。
in vec4 LightIntensity;
out vec4 color;
void main(void) {
color = vec4(LightIntensity);
}
目前得到一个没有阴影的黑色立方体。可能我在着色器中做错了什么，我不知道是哪一个 :(
更新：
顶点
layout(location = 0) in vec4 vert;
layout(location = 1) in vec4 color;
layout(location = 2) in vec2 texcoord;
layout(location = 3) in vec4 normal;
out vec2 fragtexcoord;
out vec4 fragnormal;
uniform mat4 m_model;
uniform mat4 m_view;
uniform mat4 m_proj;
void main() {
gl_Position = m_proj * m_view * m_model * vert;
fragtexcoord = texcoord;
fragnormal = normal;
}
片段
in vec2 fragtexcoord;
in vec4 fragnormal;
out vec4 fragment_color;
uniform sampler2D textureunit;
void main(void) {
vec4 lt_ambient = vec4(0.2, 0.2, 0.2, 1.0);
vec4 lt_direct = vec4(0.8, 0.8, 0.8, 1.0);
vec4 lt_direct_dir = vec4(1.5, 1.0, 1.0, 1.0);
vec4 color = texture(textureunit, fragtexcoord);
fragment_color = (lt_ambient + (lt_direct * dot(lt_direct_dir, -fragnormal))) * color;
}
我不知道要为 lt_direct_dir 添加什么，这就是为什么它具有这样的值:)
更新：下面是我的工作着色器
// vertex shader
layout(location = 0) in vec4 vert;
layout(location = 1) in vec4 color;
layout(location = 2) in vec2 texcoord;
layout(location = 3) in vec4 normal;
out vec4 fragposition;
out vec4 fragcolor;
out vec4 fragnormal;
out vec2 fragtexcoord;
uniform mat4 m_model;
uniform mat4 m_view;
uniform mat4 m_proj;
uniform vec4 lightpos;
void main() {
gl_Position = m_proj * m_view * m_model * vert;
mat4 m_normal = transpose(inverse(m_model));
fragposition = m_model * vert;
fragnormal = m_normal * normal;
fragtexcoord = texcoord;
}
// fragment shader
in vec4 fragposition;
in vec4 fragnormal;
in vec2 fragtexcoord;
out vec4 fragment_color;
uniform sampler2D textureunit;
void main() {
vec4 lt_pnt_pos = vec4(2.5, 2.5, 2.5, 1.0);
vec4 lt_pnt_col = vec4(0.8, 0.8, 0.8, 1.0);
vec4 lt_amb_col = vec4(0.2, 0.2, 0.2, 1.0);
vec4 lt_dir = normalize(lt_pnt_pos - fragposition);
float li = dot(fragnormal, lt_dir);
if(li < 0.0) {
li = 0.0;
}
vec4 color = texture(textureunit, fragtexcoord);
fragment_color = color * (lt_amb_col + (lt_pnt_col * li));
}
normal/bump 地图
在不增加几何复杂性的情况下提供精细的细节，这意味着以极低的性能成本提供更多细节。 Normal/bump 地图是粗糙的可选。
普通着色（片段着色器）
法线是垂直于 fragment/face/primitive 的向量，它有 2 个用途：
- 暗淡的表面照明
让我们有：
color- 每个 fragment/face/primitive 颜色（用纹理调制）normal- 每个 fragment/face/primitive 3D 法向量（指向网格外）lt_ambient,lt_direct- 灯光颜色和强度lt_direct_dir- 定向光方向
那么输出就简单了：
fragment_color=(lt_ambient+(lt_direct*dot(lt_direct_dir,-normal))*color;
这称为正常着色
dot returns cos(angle between light and normal) 如果你想要摊位侧面的几何形状，那么使用 fabs(dot(...))。加在一起的光色和强度矢量不应超过每个通道 1.0，否则夹紧可能会导致颜色伪影。使用例如：
lt_ambient=(0.2,0.2,0.2)lt_direct =(0.8,0.8,0.8)
as lt_direct_dir 您可以使用 (fragment_xyz-Sun.xyz) 并归一化为单位向量或使用相机视角方向。 点积需要单位向量，否则无法正常工作
- 反射
如果您有任何环境贴图 (cube_map)，那么您可以添加倒影。你得到了片段 (x,y,z) 坐标和 normal 所以你可以计算反射观察方向的方向并添加它指向结果的纹素 fragment_color.
还有更多的东西，比如镜面高光和不同的光方程，但我认为你应该先从法线着色开始。当你掌握了基础知识，那么理解更高级的东西就没问题了，只要永远记住背后的东西......
[edit1] 既然你是新手，那么你显然需要完整的例子来开始：
所以这里用 C++ 完成了 GL+VAO/VBO+GLSL+shaders 的例子。当我使用 Borland 环境时，它是 VCL 形式的应用程序，因此只需忽略 VCL 内容并仅提取您需要的内容。这是它的样子：
那个十字是我用来目视检查正确性的点光源位置，那个箭头（手绘）显示的是平均光线方向。
normal_shading.glsl_vert
// Vertex
#version 400 core
layout(location = 0) in vec3 pos;
layout(location = 2) in vec3 nor;
layout(location = 3) in vec3 col;
uniform mat4 m_model; // model matrix
uniform mat4 m_normal; // model matrix with origin=(0,0,0)
uniform mat4 m_view; // inverse of camera matrix
uniform mat4 m_proj; // projection matrix
out vec3 pixel_pos; // fragment position [GCS]
out vec3 pixel_col; // fragment surface color
out vec3 pixel_nor; // fragment surface normal [GCS]
void main()
{
pixel_col=col;
pixel_pos=(m_model*vec4(pos,1)).xyz;
pixel_nor=(m_normal*vec4(nor,1)).xyz;
gl_Position=m_proj*m_view*m_model*vec4(pos,1);
}
normal_shading.glsl_frag
// Fragment
#version 400 core
uniform vec3 lt_pnt_pos;// point light source position [GCS]
uniform vec3 lt_pnt_col;// point light source color&strength
uniform vec3 lt_amb_col;// ambient light source color&strength
in vec3 pixel_pos; // fragment position [GCS]
in vec3 pixel_col; // fragment surface color
in vec3 pixel_nor; // fragment surface normal [GCS]
out vec4 col;
void main()
{
float li;
vec3 c,lt_dir;
lt_dir=normalize(lt_pnt_pos-pixel_pos); // vector from fragment to point light source in [GCS]
li=dot(pixel_nor,lt_dir);
if (li<0.0) li=0.0;
c=pixel_col*(lt_amb_col+(lt_pnt_col*li));
col=vec4(c,1.0);
}
gl_simple.h
//---------------------------------------------------------------------------
//--- GL simple ver: 1.000 --------------------------------------------------
//---------------------------------------------------------------------------
#define GLEW_STATIC
#include "glew.c"
#include <gl\gl.h>
#include <gl\glu.h>
//---------------------------------------------------------------------------
//--- OpenGL GL example -----------------------------------------------------
//---------------------------------------------------------------------------
int xs,ys; // screen size
HDC hdc=NULL; // device context
HGLRC hrc=NULL; // rendering context
int gl_inicialized=0;
int gl_init(HWND Handle);
void gl_exit();
void gl_draw();
void gl_resize(int _xs,int _ys);
//---------------------------------------------------------------------------
//--- OpenGL GLSL example ---------------------------------------------------
//---------------------------------------------------------------------------
GLint prog_id=0, // whole program
vert_id=0, // vertex shader
frag_id=0; // fragment shader
char glsl_log[4096];// compile/link GLSL log
int glsl_logs=0;
void glsl_init(char *vert,char *frag); // create/compile/link GLSL program
void glsl_exit();
//---------------------------------------------------------------------------
//--- OpenGL VAO example ----------------------------------------------------
//---------------------------------------------------------------------------
#pragma pack(1)
//#define vao_indices
GLuint vbo[4]={-1,-1,-1,-1};
GLuint vao[4]={-1,-1,-1,-1};
const GLfloat vao_pos[]=
{
// x y z //ix
-1.0,+1.0,-1.0, //0
+1.0,+1.0,-1.0, //1
+1.0,-1.0,-1.0, //2
-1.0,-1.0,-1.0, //3
-1.0,-1.0,+1.0, //4
+1.0,-1.0,+1.0, //5
+1.0,+1.0,+1.0, //6
-1.0,+1.0,+1.0, //7
#ifndef vao_indices
-1.0,-1.0,-1.0, //3
+1.0,-1.0,-1.0, //2
+1.0,-1.0,+1.0, //5
-1.0,-1.0,+1.0, //4
+1.0,-1.0,-1.0, //2
+1.0,+1.0,-1.0, //1
+1.0,+1.0,+1.0, //6
+1.0,-1.0,+1.0, //5
+1.0,+1.0,-1.0, //1
-1.0,+1.0,-1.0, //0
-1.0,+1.0,+1.0, //7
+1.0,+1.0,+1.0, //6
-1.0,+1.0,-1.0, //0
-1.0,-1.0,-1.0, //3
-1.0,-1.0,+1.0, //4
-1.0,+1.0,+1.0, //7
#endif
};
const GLfloat vao_col[]=
{
// r g b //ix
0.0,0.0,0.0, //0
1.0,0.0,0.0, //1
1.0,1.0,0.0, //2
0.0,1.0,0.0, //3
0.0,0.0,1.0, //4
1.0,0.0,1.0, //5
1.0,1.0,1.0, //6
0.0,1.0,1.0, //7
#ifndef vao_indices
0.0,0.0,0.0, //0
1.0,0.0,0.0, //1
1.0,0.0,1.0, //5
0.0,0.0,1.0, //4
1.0,0.0,0.0, //1
1.0,1.0,0.0, //2
1.0,1.0,1.0, //6
1.0,0.0,1.0, //5
1.0,1.0,0.0, //2
0.0,1.0,0.0, //3
0.0,1.0,1.0, //7
1.0,1.0,1.0, //6
0.0,1.0,0.0, //3
0.0,0.0,0.0, //0
0.0,0.0,1.0, //4
0.0,1.0,1.0, //7
#endif
};
#ifndef vao_indices
const GLfloat vao_nor[]=
{
// nx ny nz //ix
0.0, 0.0,-1.0, //0
0.0, 0.0,-1.0, //1
0.0, 0.0,-1.0, //2
0.0, 0.0,-1.0, //3
0.0, 0.0,+1.0, //4
0.0, 0.0,+1.0, //5
0.0, 0.0,+1.0, //6
0.0, 0.0,+1.0, //7
0.0,-1.0, 0.0, //0
0.0,-1.0, 0.0, //1
0.0,-1.0, 0.0, //5
0.0,-1.0, 0.0, //4
+1.0, 0.0, 0.0, //1
+1.0, 0.0, 0.0, //2
+1.0, 0.0, 0.0, //6
+1.0, 0.0, 0.0, //5
0.0,+1.0, 0.0, //2
0.0,+1.0, 0.0, //3
0.0,+1.0, 0.0, //7
0.0,+1.0, 0.0, //6
-1.0, 0.0, 0.0, //3
-1.0, 0.0, 0.0, //0
-1.0, 0.0, 0.0, //4
-1.0, 0.0, 0.0, //7
};
#endif
#ifdef vao_indices
const GLuint vao_ix[]=
{
0,1,2,3,
4,5,6,7,
3,2,5,4,
2,1,6,5,
1,0,7,6,
0,3,4,7,
};
#endif
#pragma pack()
void vao_init();
void vao_exit();
void vao_draw();
//---------------------------------------------------------------------------
//--- bodies: ---------------------------------------------------------------
//---------------------------------------------------------------------------
int gl_init(HWND Handle)
{
if (gl_inicialized) return 1;
hdc = GetDC(Handle); // get device context
PIXELFORMATDESCRIPTOR pfd;
ZeroMemory( &pfd, sizeof( pfd ) ); // set the pixel format for the DC
pfd.nSize = sizeof( pfd );
pfd.nVersion = 1;
pfd.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
pfd.iPixelType = PFD_TYPE_RGBA;
pfd.cColorBits = 24;
pfd.cDepthBits = 24;
pfd.iLayerType = PFD_MAIN_PLANE;
SetPixelFormat(hdc,ChoosePixelFormat(hdc, &pfd),&pfd);
hrc = wglCreateContext(hdc); // create current rendering context
if(hrc == NULL)
{
ShowMessage("Could not initialize OpenGL Rendering context !!!");
gl_inicialized=0;
return 0;
}
if(wglMakeCurrent(hdc, hrc) == false)
{
ShowMessage("Could not make current OpenGL Rendering context !!!");
wglDeleteContext(hrc); // destroy rendering context
gl_inicialized=0;
return 0;
}
gl_resize(1,1);
glEnable(GL_DEPTH_TEST); // Zbuf
glDisable(GL_CULL_FACE); // vynechavaj odvratene steny
glDisable(GL_TEXTURE_2D); // pouzivaj textury, farbu pouzivaj z textury
glDisable(GL_BLEND); // priehladnost
glShadeModel(GL_SMOOTH); // gourard shading
glClearColor(0.0f, 0.0f, 0.0f, 1.0f); // background color
gl_inicialized=1;
glewInit();
return 1;
}
//---------------------------------------------------------------------------
void gl_exit()
{
if (!gl_inicialized) return;
wglMakeCurrent(NULL, NULL); // release current rendering context
wglDeleteContext(hrc); // destroy rendering context
gl_inicialized=0;
}
//---------------------------------------------------------------------------
void gl_resize(int _xs,int _ys)
{
xs=_xs;
ys=_ys;
if (xs<=0) xs = 1; // Prevent a divide by zero
if (ys<=0) ys = 1;
if (!gl_inicialized) return;
glViewport(0,0,xs,ys); // Set Viewport to window dimensions
glMatrixMode(GL_PROJECTION); // operacie s projekcnou maticou
glLoadIdentity(); // jednotkova matica projekcie
gluPerspective(30,float(xs)/float(ys),0.1,100.0); // matica=perspektiva,120 stupnov premieta z viewsize do 0.1
glMatrixMode(GL_TEXTURE); // operacie s texturovou maticou
glLoadIdentity(); // jednotkova matica textury
glMatrixMode(GL_MODELVIEW); // operacie s modelovou maticou
glLoadIdentity(); // jednotkova matica modelu (objektu)
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
void glsl_init(char *vert,char *frag)
{
const int _size=1024;
GLint status,siz=0,i;
const char * VS = vert;
const char * FS = frag;
glsl_logs=0;
if (prog_id<=0) prog_id=glCreateProgram();
if (vert_id<=0) vert_id=glCreateShader(GL_VERTEX_SHADER); else glDetachShader(prog_id,vert_id);
if (vert)
{
glShaderSource(vert_id, 1, &VS,NULL);
glCompileShader(vert_id);
glAttachShader(prog_id,vert_id);
glGetShaderiv(vert_id,GL_COMPILE_STATUS,&status);
const char t[]="[Vertex]\r\n"; for (i=0;t[i];i++) { glsl_log[glsl_logs]=t[i]; glsl_logs++; }
glGetShaderInfoLog(vert_id,_size,&siz,glsl_log+glsl_logs);
glsl_logs+=siz;
}
if (frag_id<=0) frag_id=glCreateShader(GL_FRAGMENT_SHADER); else glDetachShader(prog_id,frag_id);
if (frag)
{
glShaderSource(frag_id, 1, &FS,NULL);
glCompileShader(frag_id);
glAttachShader(prog_id,frag_id);
glGetShaderiv(frag_id,GL_COMPILE_STATUS,&status);
const char t[]="[Fragment]\r\n"; for (i=0;t[i];i++) { glsl_log[glsl_logs]=t[i]; glsl_logs++; }
glGetShaderInfoLog(frag_id,_size,&siz,glsl_log+glsl_logs);
glsl_logs+=siz;
}
glLinkProgram(prog_id);
glGetProgramiv(prog_id,GL_LINK_STATUS,&status);
const char t[]="[Program]\r\n"; for (i=0;t[i];i++) { glsl_log[glsl_logs]=t[i]; glsl_logs++; }
glGetProgramInfoLog(prog_id,_size,&siz,glsl_log+glsl_logs);
glsl_logs+=siz;
glReleaseShaderCompiler();
glsl_log[glsl_logs]=0;
}
//------------------------------------------------------------------------------
void glsl_exit()
{
glUseProgram(0);
if (vert_id>0) { glDetachShader(prog_id,vert_id); glDeleteShader(vert_id); }
if (frag_id>0) { glDetachShader(prog_id,frag_id); glDeleteShader(frag_id); }
if (prog_id>0) { glDeleteShader(prog_id); }
glsl_log[0]=0;
}
//---------------------------------------------------------------------------
//------------------------------------------------------------------------------
void vao_init()
{
GLuint i;
glGenVertexArrays(4,vao);
glGenBuffers(4,vbo);
glBindVertexArray(vao[0]);
i=0; // vertex
glBindBuffer(GL_ARRAY_BUFFER,vbo[i]);
glBufferData(GL_ARRAY_BUFFER,sizeof(vao_pos),vao_pos,GL_STATIC_DRAW);
glEnableVertexAttribArray(i);
glVertexAttribPointer(i,3,GL_FLOAT,GL_FALSE,0,0);
i=1; // indices
#ifdef vao_indices
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,vbo[i]);
glBufferData(GL_ELEMENT_ARRAY_BUFFER,sizeof(vao_ix),vao_ix,GL_STATIC_DRAW);
glEnableVertexAttribArray(i);
glVertexAttribIPointer(i,4,GL_UNSIGNED_INT,0,0);
#endif
i=2; // normal
#ifndef vao_indices
glBindBuffer(GL_ARRAY_BUFFER,vbo[i]);
glBufferData(GL_ARRAY_BUFFER,sizeof(vao_nor),vao_nor,GL_STATIC_DRAW);
glEnableVertexAttribArray(i);
glVertexAttribPointer(i,3,GL_FLOAT,GL_FALSE,0,0);
#endif
i=3; // color
glBindBuffer(GL_ARRAY_BUFFER,vbo[i]);
glBufferData(GL_ARRAY_BUFFER,sizeof(vao_col),vao_col,GL_STATIC_DRAW);
glEnableVertexAttribArray(i);
glVertexAttribPointer(i,3,GL_FLOAT,GL_FALSE,0,0);
glBindVertexArray(0);
glBindBuffer(GL_ARRAY_BUFFER,0);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,0);
glDisableVertexAttribArray(0);
glDisableVertexAttribArray(1);
glDisableVertexAttribArray(2);
glDisableVertexAttribArray(3);
}
//---------------------------------------------------------------------------
void vao_exit()
{
glDeleteVertexArrays(4,vao);
glDeleteBuffers(4,vbo);
}
//---------------------------------------------------------------------------
void vao_draw()
{
glBindVertexArray(vao[0]);
#ifndef vao_indices
glDrawArrays(GL_QUADS,0,sizeof(vao_pos)/sizeof(vao_pos[0])); // QUADS ... no indices
#endif
#ifdef vao_indices
glDrawElements(GL_QUADS,sizeof(vao_ix)/sizeof(vao_ix[0]),GL_UNSIGNED_INT,0); // indices (choose just one line not both !!!)
#endif
glBindVertexArray(0);
}
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
VCL App主窗体来源：
//---------------------------------------------------------------------------
#include <vcl.h>
#pragma hdrstop
#include "Unit1.h"
#include "gl_simple.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
//---------------------------------------------------------------------------
GLfloat lt_pnt_pos[3]={+2.5,+2.5,+2.5};
GLfloat lt_pnt_col[3]={0.8,0.8,0.8};
GLfloat lt_amb_col[3]={0.2,0.2,0.2};
//---------------------------------------------------------------------------
void gl_draw()
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// load values into shader
GLint i,id;
GLfloat m[16];
glUseProgram(prog_id);
id=glGetUniformLocation(prog_id,"lt_pnt_pos"); glUniform3fv(id,1,lt_pnt_pos);
id=glGetUniformLocation(prog_id,"lt_pnt_col"); glUniform3fv(id,1,lt_pnt_col);
id=glGetUniformLocation(prog_id,"lt_amb_col"); glUniform3fv(id,1,lt_amb_col);
glGetFloatv(GL_MODELVIEW_MATRIX,m);
id=glGetUniformLocation(prog_id,"m_model" ); glUniformMatrix4fv(id,1,GL_FALSE,m);
m[12]=0.0; m[13]=0.0; m[14]=0.0;
id=glGetUniformLocation(prog_id,"m_normal" ); glUniformMatrix4fv(id,1,GL_FALSE,m);
for (i=0;i<16;i++) m[i]=0.0; m[0]=1.0; m[5]=1.0; m[10]=1.0; m[15]=1.0;
id=glGetUniformLocation(prog_id,"m_view" ); glUniformMatrix4fv(id,1,GL_FALSE,m);
glGetFloatv(GL_PROJECTION_MATRIX,m);
id=glGetUniformLocation(prog_id,"m_proj" ); glUniformMatrix4fv(id,1,GL_FALSE,m);
// draw VAO cube
vao_draw();
// turn of shader
glUseProgram(0);
// rotate the cube to see animation
glMatrixMode(GL_MODELVIEW);
glRotatef(1.0,0.0,1.0,0.0);
glRotatef(1.0,1.0,0.0,0.0);
// render point light source in [GCS]
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadIdentity();
GLfloat x,y,z,d=0.25;
x=lt_pnt_pos[0];
y=lt_pnt_pos[1];
z=lt_pnt_pos[2];
glBegin(GL_LINES);
glColor3fv(lt_pnt_col);
glVertex3f(x-d,y,z);
glVertex3f(x+d,y,z);
glVertex3f(x,y-d,z);
glVertex3f(x,y+d,z);
glVertex3f(x,y,z-d);
glVertex3f(x,y,z+d);
glEnd();
glMatrixMode(GL_MODELVIEW);
glPopMatrix();
glFlush();
SwapBuffers(hdc);
}
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner):TForm(Owner)
{
gl_init(Handle);
int hnd,siz; char vertex[4096],fragment[4096];
hnd=FileOpen("normal_shading.glsl_vert",fmOpenRead); siz=FileSeek(hnd,0,2); FileSeek(hnd,0,0); FileRead(hnd,vertex ,siz); vertex [siz]=0; FileClose(hnd);
hnd=FileOpen("normal_shading.glsl_frag",fmOpenRead); siz=FileSeek(hnd,0,2); FileSeek(hnd,0,0); FileRead(hnd,fragment,siz); fragment[siz]=0; FileClose(hnd);
glsl_init(vertex,fragment);
hnd=FileCreate("GLSL.txt"); FileWrite(hnd,glsl_log,glsl_logs); FileClose(hnd);
vao_init();
}
//---------------------------------------------------------------------------
void __fastcall TForm1::FormDestroy(TObject *Sender)
{
gl_exit();
glsl_exit();
vao_exit();
}
//---------------------------------------------------------------------------
void __fastcall TForm1::FormResize(TObject *Sender)
{
gl_resize(ClientWidth,ClientHeight);
glMatrixMode(GL_PROJECTION);
glTranslatef(0,0,-15.0);
}
//---------------------------------------------------------------------------
void __fastcall TForm1::FormPaint(TObject *Sender)
{
gl_draw();
}
//---------------------------------------------------------------------------
void __fastcall TForm1::Timer1Timer(TObject *Sender)
{
gl_draw();
}
//---------------------------------------------------------------------------
void __fastcall TForm1::FormMouseWheel(TObject *Sender, TShiftState Shift, int WheelDelta, TPoint &MousePos, bool &Handled)
{
GLfloat dz=2.0;
if (WheelDelta<0) dz=-dz;
glMatrixMode(GL_PROJECTION);
glTranslatef(0,0,dz);
gl_draw();
}
//---------------------------------------------------------------------------
不要忘记将布局更改为您的布局，仅当这已经有效时才添加纹理和内容，并始终检查 GLSL.txt（compile/link 日志）文件以查看是否一切正常.
你还需要 GLEW 所以请看
- GLEW sourceforge
- Building glew on windows with mingw32
这是带有纹理图集的相同示例：
- Texturing a cube with different images using OpenGL