1
我正在使用GLKit繪製一個像素。我可以成功地繪製在(10,10)的像素座標,如果我有:GLKit:[繪製像素]初始化GLfloat陣列
glClearColor(0.65f, 0.65f, 0.65f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// Prepare the effect for rendering
[self.effect prepareToDraw];
GLfloat points[] =
{
10.0f, 10.0f,
};
glClearColor(1.0f, 1.0f, 0.0f, 1.0f);
GLuint bufferObjectNameArray;
glGenBuffers(1, &bufferObjectNameArray);
glBindBuffer(GL_ARRAY_BUFFER, bufferObjectNameArray);
glBufferData(
GL_ARRAY_BUFFER,
sizeof(points),
points,
GL_STATIC_DRAW);
glEnableVertexAttribArray(GLKVertexAttribPosition);
glVertexAttribPointer(
GLKVertexAttribPosition,
2,
GL_FLOAT,
GL_FALSE,
2*4,
NULL);
glDrawArrays(GL_POINTS, 0, 1);
但我想在運行時多少決定和正是我想要畫的像素,所以我想這一點,但它是借鑑像素在(10,0),這裏有什麼錯誤:
glClearColor(0.65f, 0.65f, 0.65f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// Prepare the effect for rendering
[self.effect prepareToDraw];
GLfloat *points = (GLfloat*)malloc(sizeof(GLfloat) * 2);
for (int i=0; i<2; i++) {
points[i] = 10.0f;
}
glClearColor(1.0f, 1.0f, 0.0f, 1.0f);
GLuint bufferObjectNameArray;
glGenBuffers(1, &bufferObjectNameArray);
glBindBuffer(GL_ARRAY_BUFFER, bufferObjectNameArray);
glBufferData(
GL_ARRAY_BUFFER,
sizeof(points),
points,
GL_STATIC_DRAW);
glEnableVertexAttribArray(GLKVertexAttribPosition);
glVertexAttribPointer(
GLKVertexAttribPosition,
2,
GL_FLOAT,
GL_FALSE,
2*4,
NULL);
glDrawArrays(GL_POINTS, 0, 1);
請幫助我。
編輯: 問題 其實這個問題是:我無法弄清楚是什麼之間的區別:我的選擇將是這個問題
GLfloat points[] =
{
10.0f, 10.0f,
};
和
GLfloat *points = (GLfloat*)malloc(sizeof(GLfloat) * 2);
for (int i=0; i<2; i++) {
points[i] = 10.0f;
}