Is it possible to have a vertex shader and the fragment shader in the same file?
I don't think so. The [font=courier new,courier,monospace]void main()[/font] functions for the vertex shader and fragment shader would conflict.
You could always create a wrapper file in a format like XML in which you put both your fragment and vertex shaders. You can then parse the XML file and read the two different sources and compile them as normal.
I think you could also pull this off with some pre-processor magic though
I think you could also pull this off with some pre-processor magic though
I think you could also pull this off with some pre-processor magic though
The opengl api requires you to split them before loading, so I don't think the preprocessor will help you?
But maybe just a simple marker in the file you can look for?
[source lang="cpp"]#vertex
main() {
..
}
#fragment
main() {
...
}
[/source]
Should be simple to write some loader code that finds and split the file on the markers
Edit:
I realized how to do it with preprocessor, should also work
Just have a vertex_main and a fragment_main that you patch in a #define for at the top of the file at load.
Interesting concept, might be useful
I realized how to do it with preprocessor, should also work
Just have a vertex_main and a fragment_main that you patch in a #define for at the top of the file at load.
Interesting concept, might be useful
Yeah that's what I was thinking as well, haven't tested it though but I believe this should work.
I used a marker and do a quick string function after I load the file to replace the markers with 0's and save offsets, Then I pass those pointers to the compiler. [vertex shader] [fragment shader] [geometry shader] is what I use. I also have shader definition which allows me to create indexes to attributes and other data opengl needs to index data.
So it ends up looking like this.
[source lang="plain"]
[Shader Definition]
[0] = attribute vPosition
[1] = uniform mModelView
[2] = uniform mProjection
frag fragColor0
[Vertex shader]
#version 150
in vec3 vPosition;
uniform mat4 mModelView;
uniform mat4 mProjection;
void main(void)
{
vec4 posTemp = mModelView * vec4(vPosition, 1.0);
gl_Position = mProjection * posTemp;
}
[Fragment shader]
#version 150
out vec4 fragColor0;
void main (void)
{
// Save it squared
fragColor0 = vec4(0, 0, 0, 0);
}
[/source]
So it ends up looking like this.
[source lang="plain"]
[Shader Definition]
[0] = attribute vPosition
[1] = uniform mModelView
[2] = uniform mProjection
frag fragColor0
[Vertex shader]
#version 150
in vec3 vPosition;
uniform mat4 mModelView;
uniform mat4 mProjection;
void main(void)
{
vec4 posTemp = mModelView * vec4(vPosition, 1.0);
gl_Position = mProjection * posTemp;
}
[Fragment shader]
#version 150
out vec4 fragColor0;
void main (void)
{
// Save it squared
fragColor0 = vec4(0, 0, 0, 0);
}
[/source]
A different way to do with with macro magic is something like:
Shader.glsl
Source File.cpp
Shader.glsl
#ifdef COMPILING_VERTEX_SHADER
// vertex shader
void main()
{}
#endif
#ifdef COMPILING_FRAGMENT_SHADER
// fragment shader
void main()
{}
#endif
Source File.cpp
std::string fileContents = fileToString("Shader.glsl"); // load it as a string
std::string compilingString = "#define COMPILNG_VERTEX_SHADER\n" + fileContents;
// load vertex shader...
compilingString = "#define COMPILING_FRAGMENT_SHADER\n" + fileContents;
// load fragment shader...
A different way to do with with macro magic is something like:
Shader.glsl
#ifdef COMPILING_VERTEX_SHADER
// vertex shader
void main()
{}
#endif
#ifdef COMPILING_FRAGMENT_SHADER
// fragment shader
void main()
{}
#endif
Source File.cpp
std::string fileContents = fileToString("Shader.glsl"); // load it as a string
std::string compilingString = "#define COMPILNG_VERTEX_SHADER\n" + fileContents;
// load vertex shader...
compilingString = "#define COMPILING_FRAGMENT_SHADER\n" + fileContents;
// load fragment shader...
Yep, that's pretty much what Olof Hedman and I were talking about, should work just fine.
I use Cornstalks' suggestion and it works great; it's nice that glShaderSource takes an array of strings as it's source param because you can just pop in the appropriate #define in the first array slot.
It's also be possible to extend that to support multiple shaders of the same type in a single file, and all other combinations with another #define such as:
It's also be possible to extend that to support multiple shaders of the same type in a single file, and all other combinations with another #define such as:
#define MyVertexShaderEntryPointName main
void MyVertexShaderEntryPointName ()
{
// do stuff....
[quote name='Cornstalks' timestamp='1349901383' post='4988845']
A different way to do with with macro magic is something like:
Yep, that's pretty much what Olof Hedman and I were talking about, should work just fine.
[/quote]
Yep. I like my suggestion (and mhagain's) better though, that is to re-define the main function name.
That way you don't have to clutter your source file with #ifdefs, and the other main should be removed at link time.
This topic is closed to new replies.
Advertisement
Popular Topics
Advertisement
