我正在 Ubuntu 上编写一个简单的 OpenGL 程序,它使用顶点数组绘制两个正方形(一个在另一个前面)。由于某种原因,GL_DEPTH_TEST 似乎不起作用。后面的物体出现在前面的物体前面。深度缓冲区启用
glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH);
GL_DEPTH_TEST 启用方式
glEnable(GL_DEPTH_TEST);
并且深度缓冲区在绘制之前被清除
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
完整代码如下:
#define BUFFER_OFFSET( offset ) ((GLvoid*) (offset))
#define NUM_VERTICES 8
vec4 vertices[8] =
{{0.0, 0.0, -0.25, 1.0}, // front
{0.0, 0.5, -0.25, 1.0},
{0.5, 0.5, -0.25, 1.0},
{0.5, 0.0, -0.25, 1.0},
{0.25, 0.25, -0.75, 1.0}, // back
{0.25, 0.75, -0.75, 1.0},
{0.75, 0.75, -0.75, 1.0},
{0.75, 0.25, -0.75, 1.0}};
vec4 vertex_colors[8] =
{{1.0, 0.0, 0.0, 1.0}, // red
{1.0, 0.0, 0.0, 1.0},
{1.0, 0.0, 0.0, 1.0},
{1.0, 0.0, 0.0, 1.0},
{0.0, 1.0, 0.0, 1.0}, // green
{0.0, 1.0, 0.0, 1.0},
{0.0, 1.0, 0.0, 1.0},
{0.0, 1.0, 0.0, 1.0}};
void init(void)
{
GLuint program = initShader("vshader_td.glsl", "fshader_td.glsl");
glUseProgram(program);
GLuint vao;
glGenVertexArrays(1, &vao);
glBindVertexArray(vao);
GLuint buffer;
glGenBuffers(1, &buffer);
glBindBuffer(GL_ARRAY_BUFFER, buffer);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices) + sizeof(vertex_colors), NULL, GL_STATIC_DRAW);
glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(vertices), vertices);
glBufferSubData(GL_ARRAY_BUFFER, sizeof(vertices), sizeof(vertex_colors), vertex_colors);
GLuint vPosition = glGetAttribLocation(program, "vPosition");
glEnableVertexAttribArray(vPosition);
glVertexAttribPointer(vPosition, 4, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
GLuint vColor = glGetAttribLocation(program, "vColor");
glEnableVertexAttribArray(vColor);
glVertexAttribPointer(vColor, 4, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(sizeof(points)));
glEnable(GL_DEPTH_TEST);
glClearColor(1.0, 1.0, 1.0, 1.0);
}
void display(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glDrawArrays(GL_QUADS, 0, NUM_VERTICES);
glutSwapBuffers();
}
int main(int argc, char **argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH);
glutInitWindowSize(512, 512);
glutCreateWindow("Test Depth");
glewInit();
init();
glutDisplayFunc(display);
glutMainLoop();
trả về 0;
}
顶点着色器如下所示: #版本130
in vec4 vPosition;
in vec4 vColor;
out vec4 color;
void main()
{
color = vColor;
gl_Position = vPosition;
}
片段着色器如下所示: #版本130
in vec4 color;
out vec4 fColor;
void main()
{
fColor = color;
}
为什么前面的物体会被后面的物体挡住?
Tôi là một lập trình viên xuất sắc, rất giỏi!