具有多个缓冲区的片段着色器颜色错误
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我最近一直在尝试使用OpenGL,并再次陷入困境。如果在我的程序中我通过制服设置颜色,我可以使用我选择的任何颜色绘制多个顶点数组。但是为顶点数组对象传递两个缓冲区会导致奇怪的着色,其中0表示顶点位置,1表示颜色。
我的主要功能:
int main(){
Window window(960,540);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
Reader read1("src/shaders/test.vert");
Reader read2("src/shaders/test.frag");
char * r1 = read1.getData();
char * r2 = read2.getData();
GLfloat vert[] = {
0, 0, 0,
0, 3, 0,
8, 3, 0,
8, 0, 0
};
GLushort indices[] = {
0,1,2,
2,3,0
};
GLfloat colors[] = {
1, 0, 1, 1,
1, 0, 1, 1,
1, 0, 1, 1,
1, 0, 1, 1,
};
VertexArray vao;
Buffer* vbo = new Buffer(vert, 4 * 4, 3);
vao.addBuffer(vbo, 0);
vao.addBuffer(new Buffer(colors,4 * 4 , 4), 1);
indexBuffer ibo(indices, 6);
Shader shader(r1, r2);
shader.enable();
shader.setUniformMat4("pr_matrix", mat4::orthographic(0.0f, 16.0f, 0.0f, 9.0f, -1.0f, 1.0f));
shader.setUniformMat4("ml_matrix", mat4::translation(vec3(4, 3, 0)));
shader.setUniform2f("light_pos", vec2(8.0f, 4.5f));
shader.setUniform4f("colour", vec4(0.2, 0.3, 0.8, 1));
while (!window.closed()){
window.clear();
double x, y;
x = window.getX();
y = window.getY();
shader.setUniform2f("light_pos", vec2((float)((x)*16.0f / 960.0f), (float)(9 - 9 * (y) / 540.0f)));
vao.bind();
ibo.bind();
shader.setUniform4f("colour", vec4(0.2, 0.3, 0.8, 1));
shader.setUniformMat4("ml_matrix", mat4::translation(vec3(4, 3, 0)));
glDrawElements(GL_TRIANGLES, ibo.getCount(), GL_UNSIGNED_SHORT, 0);
ibo.unbind();
vao.unbind();
window.update();
}
return 0;
}
我的顶点着色器:
#version 410 core
layout (location = 0) in vec3 position;
layout (location = 1) in vec4 color;
uniform mat4 pr_matrix ;
uniform mat4 vw_matrix = mat4(1.0f);
uniform mat4 ml_matrix = mat4(1.0f);
out DATA{
vec4 position;
vec4 color;
} vs_out;
out vec4 pos;
void main(){
gl_Position = pr_matrix * vw_matrix * ml_matrix * vec4(position,1) ;
vs_out.position = ml_matrix * vec4(position,1);
vs_out.color = color;
}
我的片段着色器:
#version 410 core
layout(location = 0) out vec4 color ;
uniform vec4 colour;
uniform vec2 light_pos;
in DATA{
vec4 position;
vec4 color;
} fs_in;
void main(){
float intensity = 1.0f / length(fs_in.position.xy - light_pos);
//color = fs_in.color * intensity;
color = fs_in.color * intensity;
}
我的缓冲类,以防需要纠正:
Buffer::Buffer(GLfloat *data, GLsizei count, GLuint compCountExt) : compCount (compCountExt) {
glGenBuffers(1, &bufferId);
glBindBuffer(GL_ARRAY_BUFFER,bufferId);
glBufferData(GL_ARRAY_BUFFER, count* sizeof(GLfloat), data, GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
}
void Buffer::bind() const {
glBindBuffer(GL_ARRAY_BUFFER, bufferId);
}
void Buffer::unbind() const {
glBindBuffer(GL_ARRAY_BUFFER, 0);
}
编辑:
vertexArray类的代码:
VertexArray::VertexArray(){
glGenVertexArrays(1,&arrayID);
}
void VertexArray::bind() const{
glBindVertexArray(arrayID);
}
void VertexArray::unbind() const{
glBindVertexArray(0);
}
VertexArray::~VertexArray(){
}
void VertexArray::addBuffer(Buffer* buffer, GLuint index){
bind();
glBindBuffer(GL_ARRAY_BUFFER, arrayID);
glEnableVertexAttribArray(index);
glVertexAttribPointer(index, buffer->getComCount(), GL_FLOAT, GL_FALSE, 0, 0);
buffer->unbind();
unbind();
}
在此类中调用顶点属性指针。
答案
glVertexAttribPointer
指的是当前绑定的数组缓冲区。这意味着你必须绑定数组缓冲区,因为你使用glVertexAttribPointer
:
void VertexArray::addBuffer(Buffer* buffer, GLuint index){
bind();
// glBindBuffer(GL_ARRAY_BUFFER, arrayID); <---- skip
buffer->bind(); // <---- bind the array buffer
glEnableVertexAttribArray(index);
glVertexAttribPointer(index, buffer->getComCount(), GL_FLOAT, GL_FALSE, 0, 0);
buffer->unbind();
unbind();
}
见OpenGL 4.6 Specification - 10.3.9 Vertex Arrays in Buffer Objects:
将缓冲区对象绑定点添加到与每个顶点数组索引关联的客户端状态。指定顶点数组的位置和组织的命令将绑定到
ARRAY_BUFFER
的缓冲区对象名称复制到与指定的顶点数组索引对应的绑定点。例如,VertexAttribPointer命令复制ARRAY_BUFFER_BINDING
的值。
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