为什么这个 GLSL Vertex Shader 无法编译？
我正在用 OpenGL 编写自己的着色器，但我很困惑为什么这个着色器无法编译。其他人可以看一下吗？
我作为顶点传递的是以下格式的 2 个浮点数（以字节分隔）：
Float 1:
Byte 1: Position X
Byte 2: Position Y
Byte 3: Position Z
Byte 4: Texture Coordinate X
Float 2:
Byte 1: Color R
Byte 2: Color G
Byte 3: Color B
Byte 4: Texture Coordinate Y
这是我的着色器：
in vec2 Data;
varying vec3 Color;
varying vec2 TextureCoords;
uniform mat4 projection_mat;
uniform mat4 view_mat;
uniform mat4 world_mat;
void main()
{
vec4 dataPosition = UnpackValues(Data.x);
vec4 dataColor = UnpackValues(Data.y);
vec4 position = dataPosition * vec4(1.0, 1.0, 1.0, 0.0);
Color = dataColor.xyz;
TextureCoords = vec2(dataPosition.w, dataColor.w)
gl_Position = projection_mat * view_mat * world_mat * position;
}
vec4 UnpackValues(float value)
{
return vec4(value % 255, (value >> 8) % 255, (value >> 16) % 255, value >> 24);
}
如果您需要更多信息，我很乐意遵守。
I'm writing my own shader with OpenGL, and I am stumped why this shader won't compile. Could anyone else have a look at it?
What I'm passing in as a vertex is 2 floats (separated as bytes) in this format:
Float 1:
Byte 1: Position X
Byte 2: Position Y
Byte 3: Position Z
Byte 4: Texture Coordinate X
Float 2:
Byte 1: Color R
Byte 2: Color G
Byte 3: Color B
Byte 4: Texture Coordinate Y
And this is my shader:
in vec2 Data;
varying vec3 Color;
varying vec2 TextureCoords;
uniform mat4 projection_mat;
uniform mat4 view_mat;
uniform mat4 world_mat;
void main()
{
vec4 dataPosition = UnpackValues(Data.x);
vec4 dataColor = UnpackValues(Data.y);
vec4 position = dataPosition * vec4(1.0, 1.0, 1.0, 0.0);
Color = dataColor.xyz;
TextureCoords = vec2(dataPosition.w, dataColor.w)
gl_Position = projection_mat * view_mat * world_mat * position;
}
vec4 UnpackValues(float value)
{
return vec4(value % 255, (value >> 8) % 255, (value >> 16) % 255, value >> 24);
}
If you need any more information, I'd be happy to comply.
如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。
绑定邮箱获取回复消息
由于您还没有绑定你的真实邮箱，如果其他用户或者作者回复了您的评论，将不能在第一时间通知您！
发布评论
评论（1）
您需要在调用之前声明
UnpackValues。 GLSL 就像 C 和 C++；名称在使用之前必须有声明。顺便说一句：您尝试做的事情不会起作用。花车就是花车；除非您使用 GLSL 4.00（并且由于您继续使用“变化”等旧术语，我猜不是），否则您无法从浮点数中提取位。事实上，右移运算符仅针对整数定义；尝试在浮点数上使用它将会失败并出现编译器错误。
GLSL 不是 C 或 C++（讽刺的是）。
如果你想打包你的数据，使用OpenGL来为你打包。发送两个包含标准化无符号字节的 vec4 属性：
您的顶点着色器将采用两个 vec4 值作为输入。由于您没有使用 glVertexAttribIPointer，OpenGL 知道您正在传递将被解释为浮点数的值。
You need to declare
UnpackValuesbefore you call it. GLSL is like C and C++; names must have a declaration before they can be used.BTW: What you're trying to do will not work. Floats are floats; unless you're working with GLSL 4.00 (and since you continue to use old terms like "varying", I'm guessing not), you cannot extract bits out of a float. Indeed, the right-shift operator is only defined for integers; attempting to use it on floats will fail with a compiler error.
GLSL is not C or C++ (ironically).
If you want to pack your data, use OpenGL to pack it for you. Send two vec4 attributes that contain normalized unsigned bytes:
Your vertex shader would take two
vec4values as inputs. Since you are not using glVertexAttribIPointer, OpenGL knows that you're passing values that are to be interpreted as floats.