Triangle

void Triangle::init()
{
 glm::vec3 t1 = p + v1;
glm::vec3 t2 = p + v2;
glm::vec3 t3 = p + v3;

// face 1
vbo.addData(&t1[0], sizeof(glm::vec3)); // vertex position
vbo.addData(&color[0], sizeof(glm::vec3)); // vertex color
vbo.addData(&t2[0], sizeof(glm::vec3));
vbo.addData(&color[0], sizeof(glm::vec3));
vbo.addData(&t3[0], sizeof(glm::vec3));
vbo.addData(&color[0], sizeof(glm::vec3));

numVertices = 3;

// VAO & VBOs
vbo.createVBO();
vbo.bindVBO();
vbo.uploadDataToGPU(GL_STATIC_DRAW);

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

int iDataStride = 2 * sizeof(glm::vec3); // vertex & color only
int iDataOffset = 0;
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, iDataStride, (void*)iDataOffset);
iDataOffset += sizeof(glm::vec3);
glEnableVertexAttribArray(1);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, iDataStride, (void*)iDataOffset);

isLoaded = true;
}

HW1

lab1 코드 실행하고 실행 및 코드분석 리포트 (init() & draw() 함수 중심으로, 장수 제한 없음. 그리고 본인의 geometry primitive를 추가한다. (Due by 9/21)

-triangle

-square

-circle (primitive type)

-indexed square

your geometry (eg. star, flower) 추가

 

glVertexAttribPointer

glVertexAttribPointer — define an array of generic vertex attribute data

https://www.opengl.org/sdk/docs/man/html/glVertexAttribPointer.xhtml

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

Parameters

index
Specifies the index of the generic vertex attribute to be modified.
size
Specifies the number of components per generic vertex attribute. Must be 1, 2, 3, 4. Additionally, the symbolic constant GL_BGRA is accepted by glVertexAttribPointer. The initial value is 4.
type
Specifies the data type of each component in the array. The symbolic constants GL_BYTE, GL_UNSIGNED_BYTE, GL_SHORT, GL_UNSIGNED_SHORT, GL_INT, and GL_UNSIGNED_INT are accepted by glVertexAttribPointer and glVertexAttribIPointer. Additionally GL_HALF_FLOAT, GL_FLOAT, GL_DOUBLE, GL_FIXED, GL_INT_2_10_10_10_REV, GL_UNSIGNED_INT_2_10_10_10_REV and GL_UNSIGNED_INT_10F_11F_11F_REV are accepted by glVertexAttribPointer. GL_DOUBLE is also accepted by glVertexAttribLPointer and is the only token accepted by the type parameter for that function. The initial value is GL_FLOAT.
normalized
For glVertexAttribPointer, specifies whether fixed-point data values should be normalized (GL_TRUE) or converted directly as fixed-point values (GL_FALSE) when they are accessed.
stride
Specifies the byte offset between consecutive generic vertex attributes. If stride is 0, the generic vertex attributes are understood to be tightly packed in the array. The initial value is 0.
pointer
Specifies a offset of the first component of the first generic vertex attribute in the array in the data store of the buffer currently bound to the GL_ARRAY_BUFFER target. The initial value is 0.

 

 

OPENGL PROGRAMMABLE PIPELINE

http://duriansoftware.com/joe/An-intro-to-modern-OpenGL.-Chapter-1:-The-Graphics-Pipeline.html

 

Modern OpenGL (OpenGL 3.x) 프로그래밍은 다음과 같은 단계로 진행한다.
1.Shader 프로그램을 만든다.
2.Vertex 자료를 Vertex Buffer Object (VBO)와 Vertex Array Object (VAO)를 만들고 이 자료를 쉐이더에 로딩한다.
3.이 자료의 위치와 쉐이더의 변수와 “연결(Connect)” 한다.
4.렌더링을 수행한다.

 

[OpenGL Part 3 ] Shaders in OpenGL