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我試圖讓每頂點基礎上某些浮點值到我的頂點着色器 - 浮動值將定義gl_PointSize的大小呈現OpenGL的緩衝區,以屬性
這裏是我的着色器:
attribute float vSpacial;
void main(void)
{
gl_FrontColor = gl_Color;
gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
gl_PointSize = vSpacial;
}
這裏是我設置緩衝區的綠黨,顏色和「空間」點大小信息:
GLint spacial = glGetAttribLocation(program, "vSpacial");
float spacialData[] = {11.0f, 50.0f, 100.0f};
GLuint VBO;
glGenBuffers(1, &VBO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(positions), &positions, GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
GLuint CBO;
glGenBuffers(1, &CBO);
glBindBuffer(GL_ARRAY_BUFFER, CBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(colors), &colors, GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
GLuint SPO;
glGenBuffers(1, &SPO);
glBindBuffer(GL_ARRAY_BUFFER, SPO);
glBufferData(GL_ARRAY_BUFFER, sizeof(spacial), &spacial, GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
,這裏是我如何渲染:
// Set up projection
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45, 1024.0/768.0, 1, 1000);
// Set up camera view
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
gluLookAt(0,0,-5,
0,0,0,
0,1,0);
glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// ---
glUseProgram(program);
glPushMatrix();
glRotatef(theta, 0.0f, 0.0f, 1.0f);
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_COLOR_ARRAY);
glEnable(GL_PROGRAM_POINT_SIZE);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glVertexPointer(3, GL_FLOAT, 0, BUFFER_OFFSET(0));
glBindBuffer(GL_ARRAY_BUFFER, CBO);
glColorPointer(3, GL_FLOAT, 0, BUFFER_OFFSET(0));
glBindBuffer(GL_ARRAY_BUFFER, SPO);
glEnableVertexAttribArray(spacial);
glVertexAttribPointer(spacial, 1, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
glDrawArrays(GL_POINTS, 0, 3);
glDisableVertexAttribArray(spacial);
glDisable(GL_PROGRAM_POINT_SIZE);
glDisableClientState(GL_COLOR_ARRAY);
glDisableClientState(GL_VERTEX_ARRAY);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glPopMatrix();
// ---
glFlush();
SwapBuffers(hDC);
theta += 1.0f;
目前我看不到任何渲染 - 如果我註釋掉線 glBindBuffer(GL_ARRAY_BUFFER,SPO); 我會看到一個點本身被渲染(不使用我傳入的空間值)。