Microsoft Word - ggbook.docx

(1)

4 GPU (Graphics Processing Unit)

4.1

4.1.1

63

(2)

( 64) " ( ) " " " 64

(3)

4.1.2

( )

GPU (Graphics Procssing Unit) (Transform) (Lighting

) T & L (Transform and Lighting)

" CG 4 4 4 4 ( ) 4 4 4 4 4 4 4 16 " ( ) (Swizzling) 2 1 65

4.1.3

(4)

GPU ( ) CPU

66

4.1.4

GPU

GPU CPU ( CPU )

(5)

(discrete) GPU PCI-Express GPU GPU GPU ( ) ( ) GPU 67 点三角形一枚の三角形四枚に細分割

(6)

4.1.5

( ) 69

4.1.6

/ (

(7)

) ( 70) 70 GPU

4.2

CPU GPU GPU (attribute) GPU (Vertex Buffer Object, VBO)

( )

(Index Buffer Object)

(Vertex Array Object)

( ) GPU ラスタライザ出力画像バーテックスシェーダフラグメントシェーダ補間画素頂点属性選択されたフラグメントバッファオブジェクトフレームバッファ基本図形

(8)

GPU 71 OpenGL 3.2 OpenGL 4.x 71 GPU アプリケーションディスプレイシェーダ頂点属性バッファオブジェクトバーテックスシェーダラスタライザフラグメントシェーダラスタオペレーションパラメータテクスチャ基本図形 uniform レジスタテクスチャメモリ映像出力クリッピングジオメトリシェーダスクリーンマッピングフレームバッファ頂点番号

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5

5.1

5.1.1

C " HLSL (High Level Shading Language)

! DirectX

! Microsoft NVIDIA " Cg (C for Graphics)

! DirectX OpenGL ! NVIDIA

" GLSL (OpenGL Shading Language, GLslang) ! OpenGL

! OpenGL ARB ( Khronos Group) GLSL (OpenGL Shading Language)

5.1.2

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72 OpenGL OpenGL 2.0

OpenGL 2013 7 4.4

GPU

OpenGL 3.2 Core Profile ( )

( ) Mac OS X 10.7 (Lion) 3 OpenGL GLSL GLSL 3 OpenGL GLSL OpenGL のバージョン 1.5 2.0 2.1 3.0 3.1 3.2 3.3 4.0 4.1 4.2 4.3 4.4 GLSL のバージョン 1.00 (100) 1.10 (110) 1.20 (120) 1.30 (130) 1.40 (140) 1.50 (150) 3.30 (330) 4.00 (400) 4.10 (410) 4.20 (420) 4.30 (430) 4.40 (440)

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5.2

73 OpenGL 3.2 Core Profile CPU

GPU GPU 73

5.3

5.3.1

GLSL 1. glCreateProgram() 2. glCreateShader() 3. glShaderSource() 4. glCompileShader() 5. glAttachShader() 6. glLinkProgram() glUseProgram()

(13)

5.3.2

" #version*150*core* in*vec4*pv;* void*main()* {* **gl_Position*=*pv;* }* 1 #version GLSL 150 OpenGL

3.2 GLSL 1.50 core Core Profile

2 pv in

in CPU

attribute

vec4 32bit (float ) 4

2 vec2 3 vec3 C “.” { .x, .y, .z, .w } { .s, .t, .p, q } { .r, .g, .b, .a } ( 4) 4 GLSL C C++ main() main() void main() 変数のデータ型内容ベクトル型の要素凡例 vec4 pv; vec4 型の変数宣言 .x .y .z .w .r .g .b .a .s .t .p .q float vec2 vec3 vec4 単精度浮動小数点 1 個単精度浮動小数点 2 個単精度浮動小数点 3 個単精度浮動小数点 4 個 pv.xy pv.rgb pv.q pv.yx pv.brg pv の第1,2要素, vec2 型 pv の第1,2,3要素, vec3 型 pv の第4要素, float 型 pv の第1,2要素の順序を入れ替えたもの, vec2 型 pv の第1,2,3要素を3,1,2の順に並べ替え, vec3 型

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CPU GPU attribute gl_Position GLSL ( ) attribute pv gl_Position " #version*150*core* out*vec4*fc;* void*main()* {* **fc*=*vec4(1.0,*0.0,*0.0,*1.0);* }* 2 fc out vec4() vec4 ( ) fc R ( ) G ( ) B ( ) A ( ) 4 ( ) discard

5.3.3

GPU glCreateProgram() (program) **const*GLuint*program(glCreateProgram());* GLuint glCreateProgram(void) ( ) 0 0

5.3.4

1 #version '#' '¥n' **static*const*GLchar**vsrc[]*=* **{* ****"#version*150*core¥n",*

(15)

****"in*vec4*pv;",* ****"void*main()",* ****"{",* ****"**gl_Position*=*pv;",* ****"}",* **};* (vobj) sizeof vsrc / sizeof vsrc[0] vsrc ( ) GL_VERTEX_SHADER GL_FRAGMENT_SHADER **const*GLuint*vobj(glCreateShader(GL_VERTEX_SHADER));* **glShaderSource(vobj,*sizeof*vsrc*/*sizeof*vsrc[0],*vsrc,*NULL);* **glCompileShader(vobj);* 1 '¥n' 2 **static*const*GLchar**vsrc*=* ****"#version*150*core¥n"* ****"in*vec4*pv;¥n"* ****"void*main()¥n"* ****"{¥n"* ****"**gl_Position*=*pv;¥n"* ****"}¥n";* **const*GLuint*vobj(glCreateShader(GL_VERTEX_SHADER));* **glShaderSource(vsrc,*1,*&vsrc,*NULL);** **glCompileShader(vobj);*

GLuint glCreateShader(GLenum shaderType)

( )

0 0

shaderType

GL_VERTEX_SHADER

GL_FRAGMENT_SHADER

void glShaderSource(GLuint shader, GLsizei count, const GLchar **string, const GLint *length) shader

glCreateShader() count

(16)

length

length NULL (0) length string

( ) length

string ('¥0')

void glCompileShader(GLuint shader) shader

**glAttachShader(program,*vobj);* **glDeleteShader(vobj);*

void glAttachShader(GLuint program, GLuint shader) program

shader

void glDetachShader(GLuint program, GLuint shader) program

shader

void glDeleteShader(GLuint shader) shader

void glDeleteProgram(GLuint program) program

glDeleteShader()

(17)

glDeleteProgram()

5.3.5

( , attribute) (attribute pv) (index) ( fc ) (colorNumber) 0 CPU GPU GPU **glBindAttribLocation(program,*0,*"pv");* **glBindFragDataLocation(program,*0,*"fc");* **glLinkProgram(program);*

void glBindAttribLocation(GLuint program, GLuint index, const GLchar *name)

attribute attribute in program attribute index name in ( ) 0 0 name in

void glBindFragDataLocation(GLuint program, GLuint colorNumber, const char *name) out program (out ) index name out ( ) 0 0 0 name out

(18)

void glLinkProgram(GLuint program) program program

5.3.6

NULL //* * //***vsrc:* * //***pv:* *in* * //***fsrc:* * //***fc:* *out* * static*GLuint*createProgram(const*char**vsrc,*const*char**pv,* **const*char**fsrc,*const*char**fc)* {* **//* * **const*GLuint*program(glCreateProgram());* * **if*(vsrc*!=*NULL)* **{* ****//* * ****const*GLuint*vobj(glCreateShader(GL_VERTEX_SHADER));* ****glShaderSource(vobj,*1,*&vsrc,*NULL);* ****glCompileShader(vobj);* * ****//* * ****glAttachShader(program,*vobj);* ****glDeleteShader(vobj);* **}* * **if*(fsrc*!=*NULL)* **{* ****//* * ****const*GLuint*fobj(glCreateShader(GL_FRAGMENT_SHADER));* ****glShaderSource(fobj,*1,*&fsrc,*NULL);* ****glCompileShader(fobj);* * ****//* * ****glAttachShader(program,*fobj);* ****glDeleteShader(fobj);* **}* * **//* * **glBindAttribLocation(program,*0,*pv);* **glBindFragDataLocation(program,*0,*fc);* **glLinkProgram(program);* * **//* * **return*program;* }*

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5.3.7

glUseProgram()

**glUseProgram(program);*

void glUseProgram(GLuint program) program 0 " main() createProgram() GLEW glUseProgram() #include*<cstdlib>* #include*<iostream>* #include*<GL/glew.h>* #include*<GLFW/glfw3.h>* * //* * static*void*cleanup()* {* **//*GLFW* * **glfwTerminate();* }* * //* * //***vsrc:* * //***pv:* *in* * //***fsrc:* * //***fc:* *out* * static*GLuint*createProgram(const*char**vsrc,*const*char**pv,* **const*char**fsrc,*const*char**fc)* {* ** * }* * * * int*main()* {* ** * * **//* * **glClearColor(1.0f,*1.0f,*1.0f,*0.0f);* * **//* * **static*const*GLchar*vsrc[]*=*

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****"void*main()¥n"* ****"{¥n"* ****"**gl_Position*=*pv;¥n"* ****"}¥n";* * **//* * **static*const*GLchar*fsrc[]*=* ****"#version*150*core¥n"* ****"out*vec4*fc;¥n"* ****"void*main()¥n"* ****"{¥n"* ****"**fc*=*vec4(1.0,*0.0,*0.0,*1.0);¥n"* ****"}¥n";* * **//* * **const*GLuint*program(createProgram(vsrc,*"pv",*fsrc,*"fc"));* * **//* * **while*(glfwWindowShouldClose(window)*==*GL_FALSE)* **{* ****//* * ****glClear(GL_COLOR_BUFFER_BIT);* * ****//* * ****glUseProgram(program);* * ****//* ****//* * ****//* * ****//* * ****glfwSwapBuffers(window);* * ****//* * ****glfwWaitEvents();* **}* }* " glUseProgram() glUseProgram(program); while ( ) ( ) glUseProgram(0);

5.4

GLSL GL_TRUE GL_FALSE //* * //***shader:* *

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//***str:* * static*GLboolean*printShaderInfoLog(GLuint*shader,*const*char**str)* {* **//* * **GLint*status;* **glGetShaderiv(shader,*GL_COMPILE_STATUS,*&status);* **if*(status*==*GL_FALSE)*std::cerr*<<*"Compile*Error*in*"*<<*str*<<*std::endl;* * **//* * **GLsizei*bufSize;* **glGetShaderiv(shader,*GL_INFO_LOG_LENGTH*,*&bufSize);* * **if*(bufSize*>*1)* **{* ****//* * ****std::vector<GLchar>*infoLog(bufSize);* ****GLsizei*length;* ****glGetShaderInfoLog(shader,*bufSize,*&length,*&infoLog[0]);* ****std::cerr*<<*&infoLog[0]*<<*std::endl;* **}* * **return*static_cast<GLboolean>(status);* }*

void glGetShaderiv(GLuint shader, GLenum pname, GLint *params) shader pname GL_SHADER_TYPE shader (GL_VERTEX_SHADER, GL_FRAGMENT_SHADER) *params GL_DELETE_STATUS shader glDeleteShader() GL_TRUE GL_FALSE *params GL_COMPILE_STATUS shader

GL_TRUE GL_FALSE *params GL_INFO_LOG_LENGTH shader *params 0 GL_SHADER_SOURCE_LENGTH shader *params 0

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params

void glGetShaderInfoLog(GLuint shader, GLsizei maxLength, GLsizei *length, GLchar *infoLog) shader maxLength infoLog length infoLog GL_TRUE GL_FALSE //* * //***program:* * static*GLboolean*printProgramInfoLog(GLuint*program)* {* **//* * **GLint*status;* **glGetProgramiv(program,*GL_LINK_STATUS,*&status);* **if*(status*==*GL_FALSE)*std::cerr*<<*"Link*Error."*<<*std::endl;* * **//* * **GLsizei*bufSize;* **glGetProgramiv(program,*GL_INFO_LOG_LENGTH,*&bufSize);* * **if*(bufSize*>*1)* **{* ****//* * ****std::vector<GLchar>*infoLog(bufSize);* ****GLsizei*length;* ****glGetProgramInfoLog(program,*bufSize,*&length,*&infoLog[0]);* ****std::cerr*<<*&infoLog[0]*<<*std::endl;* **}* * **return*static_cast<GLboolean>(status);* }*

void glGetProgramiv(GLuint program, GLenum pname, GLint *params) program

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GL_DELETE_STATUS program glDeleteProgram() GL_TRUE GL_FALSE *params GL_LINK_STATUS program

GL_TRUE GL_FALSE *params GL_VALIDATE_STATUS

program glValidateProgram()

*params *params OpenGL

GL_TRUE GL_FALSE GL_INFO_LOG_LENGTH program *params 0 GL_ATTACHED_SHADERS program *params params void glValidateProgram(GLuint program)

OpenGL

glGetProgramiv() pname GL_VALIDATE_STATUS program

void glGetProgramInfoLog(GLuint program, GLsizei maxLength, GLsizei *length, GLchar *infoLog) program maxLength infoLog length (infoLog ) infoLog maxLength "

(24)

C++ vector vector #include #include*<cstdlib>* #include*<iostream>* #include*<vector>* #include*<GL/glew.h>* #include*<GLFW/glfw3.h>* * //* * static*void*cleanup()* {* **//*GLFW* * **glfwTerminate();* }* * //* * //***shader:* * //***str:* * static*GLboolean*printShaderInfoLog(GLuint*shader,*const*char**str)* {* ** * }* * //* * //***program:* * static*GLboolean*printProgramInfoLog(GLuint*program)* {* ** * }* * //* * //***vsrc:* * //***pv:* *in* * //***fsrc:* * //***fc:* *out* * static*GLuint*createProgram(const*char**vsrc,*const*char**pv,* **const*char**fsrc,*const*char**fc)* {* **//* * **const*GLuint*program(glCreateProgram());* * **if*(vsrc*!=*NULL)* **{* ****//* * ****const*GLuint*vobj(glCreateShader(GL_VERTEX_SHADER));* ****glShaderSource(vobj,*1,*&vsrc,*NULL);* ****glCompileShader(vobj);* * ****//* * ****if*(printShaderInfoLog(vobj,*"vertex*shader"))* ******glAttachShader(program,*vobj);* ****glDeleteShader(vobj);* **}* *

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**{* ****//* * ****const*GLuint*fobj(glCreateShader(GL_FRAGMENT_SHADER));* ****glShaderSource(fobj,*1,*&fsrc,*NULL);* ****glCompileShader(fobj);* * ****//* * ****if*(printShaderInfoLog(fobj,*"fragment*shader"))* ******glAttachShader(program,*fobj);* ****glDeleteShader(fobj);* **}* * **//* * **glBindAttribLocation(program,*0,*pv);* **glBindFragDataLocation(program,*0,*fc);* **glLinkProgram(program);* * **//* * **if*(printProgramInfoLog(program))* ****return*program;* * **//* *0* * **glDeleteProgram(program);* **return*0;* }* * *

5.5

GLSL C++ C++ C++ C++ readShaderSource() //* * //***name:* * static*GLchar**readShaderSource(const*char**name)* {* **//* *NULL* *NULL* * **if*(name*==*NULL)*return*NULL;* * **//* * **std::ifstream*file(name,*std::ios::binary);* **if*(file.fail())* **{* ****//* * ****std::cerr*<<*"Error:*Can't*open*source*file:*"*<<*name*<<*std::endl;* ****return*NULL;* **}* *

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**const*GLsizei*length(static_cast<GLsizei>(file.tellg()));* * **//* *(‘¥0’)* * **GLchar**buffer(new(std::nothrow)*GLchar[length*+*1]);* **if*(buffer*==*NULL)* **{* ****//* * ****std::cerr*<<*"Error:*Too*large*file:*"*<<*name*<<*std::endl;* ****file.close();* ****return*NULL;* **}* * **//* * **file.seekg(0L,*std::ios::beg);* **file.read(buffer,*length);* **buffer[length]*=*'¥0';* * **if*(file.bad())* **{* ****//* * ****std::cerr*<<*"Error:*Could*not*read*souce*file:*"*<<*name*<<*std::endl;* ****delete*buffer;* ****buffer*=*NULL;* **}* **file.close();* * **// * **return*buffer;* }* createProgram() loadProgram() //* * //***vert:* * //***pv:* *in* * //***frag:* * //***fc:* *out* * static*GLuint*loadProgram(const*char**vert,*const*char**pv,* **const*char**frag,*const*char**fc)* {* **//* * **const*GLchar**vsrc(readShaderSource(vert));* **const*GLchar**fsrc(readShaderSource(frag));* * **//* * **const*GLuint*program(createProgram(vsrc,*pv,*fsrc,*fc));* * **//* * **delete*vsrc;* **delete*fsrc;* * **//* * **return*program;* }*

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"

createProgram() readShaderSource() loadProgram() main() vsrc fsrc createProgram() loadProgram() #include*<cstdlib>* #include*<iostream>* #include*<fstream>* #include*<vector>* #include*<GL/glew.h>* #include*<GLFW/glfw3.h>* * * * //* * //***vsrc:* * //***pv:* *in* * //***fsrc:* * //***fc:* *out* * static*GLuint*createProgram(const*char**vsrc,*const*char**pv,* **const*char**fsrc,*const*char**fc)* {* ** * }* * //* * //***name:* * static*GLchar**readShaderSource(const*char**name)* {* ** * }* * //* * //***vert:* * //***pv:* *in* * //***frag:* * //***fc:* *out* * static*GLuint*loadProgram(const*char**vert,*const*char**pv,* **const*char**frag,*const*char**fc)* {* ** * }* * * * int*main()* {* ** * * **//* * **glClearColor(1.0f,*1.0f,*1.0f,*0.0f);* * **//* *vsrc* * **//* *fsrc* *

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**const*GLuint*program(loadProgram("point.vert",*"pv",*"point.frag",*"fc"));* * **//* * **while*(glfwWindowShouldClose(window)*==*GL_FALSE)* **{* **** * **}* }* C++ point.vert point.frag ( ) C++ ( ) " point.vert #version*150*core* in*vec4*pv;* void*main()* {* **gl_Position*=*pv;* }* point.frag #version*150*core* out*vec4*fc;* void*main()* {* **fc*=*vec4(1.0,*0.0,*0.0,*1.0);* }* " Xcode Mac OS X Xcode C++ Xcode C++ Xcode C++ Xcode Xcode

(29)

74

“Run ” “Options” “Working Directory”

C++

“OK” ( 75)

(30)

6

6.1 OpenGL

(GPU) (CPU) OpenGL ( 5) GLubyte C C++ unsigned

char GLfloat float GLclampf float

OpenGL 0 1 1 GLhalf

6.2 OpenGL

OpenGL (attribute) GPU GPU

(Vertex Buffer Object, VBO)

(Vertex Array Object, VAO) OpenGL

(31)

5 OpenGL

6.3

glGenVertexArrays() glBindVertexArray() **GLuint*vao;* **glGenVertexArrays(1,*&vao);* **glBindVertexArray(vao);*

void glGenVertexArrays(GLsizei n, GLuint *arrays) n arrays ( ) n OpenGL のデータ型最小ビット数説明 GLboolean ₁ _論理値 GLbyte 8 符号付き二進整数（二の補数表現） GLubyte ₈ _{符号なし二進整数} GLchar 8 文字列中の文字 GLshort ₁₆ _{符号付き二進整数（二の補数表現）} GLushort 16 符号なし二進整数 GLint ₃₂ _{符号付き二進整数（二の補数表現）} GLuint 32 符号なし二進整数 GLint64 ₆₄ _{符号付き二進整数（二の補数表現）} GLuint64 64 符号なし二進整数 GLsizei ₃₂ _{非負の二進整数で表したサイズ} GLenum 32 二進整数で表した列挙子 GLintptr _※ _{符号付き二進整数（二の補数表現）} GLsizeiptr ※ 非負の二進整数で表したサイズ GLsync _※ _{同期オブジェクトのハンドル} GLbitfield 32 ビットフィールド GLhalf ₁₆ _{符号なしの値に符号化された半精度浮動小数点数} GLfloat 32 単線度浮動小数点数 GLclampf ₃₂ _{[0, 1] にクランプされた単精度浮動小数点数} GLdouble 64 倍線度浮動小数点数 GLclampd ₆₄ _{[0, 1] にクランプされた倍精度浮動小数点数} ※ ポインタ（アドレス）を保持するのに必要なビット数

(32)

void glBindVertexArray(GLuint array) array 0

6.4

6.4.1

4 vertices **//* * **static*const*GLfloat*position[][2]*=* **{* ****{*K0.5f,*K0.5f*},* ****{**0.5f,*K0.5f*},* ****{**0.5f,**0.5f*},* ****{*K0.5f,**0.5f*}* **};* * **//* * **static*const*GLuint*vertices(sizeof*position*/*sizeof*position[0]);* GPU GLfloat

vertices sizeof (GLfloat) * 2 * vertices

**GLuint*vbo;*

**glGenBuffers(1,*&vbo);*

**glBindBuffer(GL_ARRAY_BUFFER,*vbo);* **glBufferData(GL_ARRAY_BUFFER,*

****sizeof*(GLfloat)***2***vertices,*position,*GL_STATIC_DRAW);*

void glGenBuffers(GLsizei n, GLuint *buffers) n

arrays

( ) n

void glBindBuffer(GLenum target, GLuint buffer) target

GL_ARRAY_BUFFER,

GL_COPY_READ_BUFFER, GL_COPY_WRITE_BUFFER,

(33)

GL_PIXEL_UNPACK_BUFFER, GL_TEXTURE_BUFFE, GL_UNIFORM_BUFFE, GL_TRANSFORM_FEEDBACK_BUFFER

GL_ARRAY_BUFFER array

0

void glBufferData(GLenum target, GLsizeiptr size, const GLvoid *data, GLenum usage)

( ) target size GPU data CPU ( ) size 0 GPU usage GL_STREAM_DRAW GL_STREAM_READ GL_STREAM_COPY GL_STATIC_DRAW GL_STATIC_READ

GL_STATIC_COPY GL_DYNAMIC_DRAW GL_DYNAMIC_READ

GL_DYNAMIC_COPY GPU STREAM STATIC DYNAMIC DRAW READ OpenGL (GPU) COPY OpenGL (GPU)

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6.4.2 attribute

in attribute in glVertexAttribPointer() glEnableVertexAttribArray() in **glVertexAttribPointer(0,*2,*GL_FLOAT,*GL_FALSE,*0,*0);* **glEnableVertexAttribArray(0);*

void glVertexAttribPointer(GLuint index, GLint size, GLenum type, GLboolean normalized, GLsizei stride, const GLvoid *pointer);

attribute index

glBindAttribLocation()

attribute (index) pv index 0

0 size attribute 1 2 3 4 (x, y) 2 (x, y, z) 3 2 type

attribute (pointer ) GL_BYTE

GL_UNSIGNED_BYTE GL_SHORT GL_UNSIGNED_SHORT GL_INT GL_UNSIGNED_INT GL_FLOAT GL_DOUBLE

GLfloat GL_FLOAT

normalized

GL_TRUE type (GL_BYTE GL_UNSIGNED_BYTE GL_SHORT GL_UNSIGNED_SHORT GL_INT GL_UNSIGNED_INT)

GL_FALSE GL_FALSE stride attribute (pointer ) 0 0 pointer attribute 0 int offset

static_cast<char *>(0) + offset (char *)0 + offset

(35)

void glEnableVertexAttribArray(GLuint index) attribute index attribute **glBindBuffer(GL_ARRAY_BUFFER,*0);* **glBindVertexArray(0);* glGenVertexArray() glVertexAttribPointer() glBindBuffer() " //* * //***vertices:* * //***position:* * static*GLuint*createObject(GLuint*vertices,*const*GLfloat*(*position)[2])* {* **//* * **GLuint*vao;* **glGenVertexArrays(1,*&vao);* **glBindVertexArray(vao);* * **//* * **GLuint*vbo;* **glGenBuffers(1,*&vbo);* **glBindBuffer(GL_ARRAY_BUFFER,*vbo);* **glBufferData(GL_ARRAY_BUFFER,* ****sizeof*(GLfloat)***2***vertices,*position,*GL_STATIC_DRAW);* * **//* *in* * **glVertexAttribPointer(0,*2,*GL_FLOAT,*GL_FALSE,*0,*0);* **glEnableVertexAttribArray(0);* * **//* * **glBindBuffer(GL_ARRAY_BUFFER,*0);* **glBindVertexArray(0);* * **return*vao;* }* " createObject() createRectangle() (“Object” )

(36)

//* * struct*Object* {* **//* * **GLuint*vao;* * **//* * **GLsizei*count;* };* createObject() //* * static*Object*createRectangle()* {* **//* * **static*const*GLfloat*position[][2]*=* **{* ****{*K0.5f,*K0.5f*},* ****{**0.5f,*K0.5f*},* ****{**0.5f,**0.5f*},* ****{*K0.5f,**0.5f*}* **};* * **//* * **static*const*int*vertices(sizeof*position*/*sizeof*position[0]);* * **//* * **Object*object;* **object.vao*=*createObject(vertices,*position);* **object.count*=*vertices;* * **return*object;* }*

6.5

glBindVertexArray() glDrawArrays() ( 76) ****glBindVertexArray(vao);* ****glDrawArrays(GL_LINE_LOOP,*0,*vertices);*

void glDrawArrays(GLenum mode, GLint first, GLsizei count) mode 76 OpenGL 4.0 GL_PATCHES first 0 count 4

(37)

76 OpenGL " * * //* * //***vertices:* * //***position:* * static*GLuint*createObject(GLuint*vertices,*const*GLfloat*(*position)[2])* {* ** * }* * //* * struct*Object* {* ** * };* * //* * static*Object*createRectangle()* {* ** * 0 1 2 3 4 5 GL_TRIANGLE_STRIP 0 1 2 3 ₄ 5 GL_TRIANGLE_FAN 0 1 2 3 4 5 GL_TRIANGLES 0 1 2 3 4 5 GL_LINES 0 1 2 3 4 5 GL_LINE_STRIP 0 1 2 3 4 5 GL_POINTS 0 1 2 3 4 5 GL_LINE_LOOP 0 1 2 3 4 5 GL_TRIANGLE_STRIP_ADJACENCY 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 8 9 10 11 6 7 8 9 10 11 GL_TRIANGLES_ADJACENCY GL_LINE_STRIP_ADJACENCY GL_LINES_ADJACENCY

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int*main()* {* ** * * **//* * **glClearColor(1.0f,*1.0f,*1.0f,*0.0f);* * **//* * **const*GLuint*program(loadProgram("point.vert",*"pv",*"point.frag",*"fc"));* * **//* * **const*Object*object(createRectangle());* * **//* * **while*(glfwWindowShouldClose(window)*==*GL_FALSE)* **{* ****//* * ****glClear(GL_COLOR_BUFFER_BIT);* * ****//* * ****glUseProgram(program);* * ****//* * ****glBindVertexArray(object.vao);* ****glDrawArrays(GL_LINE_LOOP,*0,*object.count);* * ****//* * ****glfwSwapBuffers(window);* * ****//* * ****glfwWaitEvents();* **}* }* " 77