easy-gl › ProgramPipeline

ProgramPipeline

Manages a separable program pipeline — a collection of independently compiled program stages. Requires OpenGL 4.1+ or GL_ARB_separate_shader_objects. Non-copyable, movable, RAII.

A separable pipeline lets you mix and match independently compiled vertex and fragment programs without having to link them together into a single Program. Each stage is compiled as a standalone Program via Program::create_separable().

Creating separable programs

// Create separable programs — each is a full Program compiled for one stage
auto vertProg = easygl::Program::create_separable(easygl::ShaderType::Vertex, vertSrc);
auto fragProg = easygl::Program::create_separable(easygl::ShaderType::Fragment, fragSrc);

// Assemble the pipeline
easygl::ProgramPipeline pipeline;
pipeline.create();
pipeline.use_stages(easygl::ShaderStageMask::Vertex, vertProg);
pipeline.use_stages(easygl::ShaderStageMask::Fragment, fragProg);
pipeline.validate();

// At render time: bind the pipeline instead of calling program.use()
pipeline.bind();
// ... draw calls ...
easygl::ProgramPipeline::unbind();

Setting uniforms without binding

With separable programs, use the set_program_uniform* family on the individual program objects. These methods bypass the need to call use():

int loc = vertProg.uniform_location("uMVP");
vertProg.set_program_uniform_matrix4(loc, mvpData);

int colorLoc = fragProg.uniform_location("uColor");
fragProg.set_program_uniform(colorLoc, 1.0f, 0.5f, 0.2f, 1.0f);

See Program — Separable program uniforms for the full list of set_program_uniform* methods.

Method reference

Method	Description
`create()`	Allocate GL pipeline handle.
`destroy()`	Free handle. Noexcept.
`bind()`	Bind this pipeline as the active program pipeline.
`unbind() [static]`	Bind pipeline 0 (disable separable pipeline).
`use_stages(stages, program)`	Assign a separable program to one or more pipeline stages.
`set_active_shader_program(program)`	Set the active program for `glUniform*` calls on this pipeline.
`validate()`	Validate the pipeline for the current GL state.
`info_log()`	Validation log string.
`is_valid_gl_object()`	True if the GL handle is currently valid.
`is_created()`	True if GL handle is allocated.
`native_handle()`	Raw GL integer ID.
`reset_handle_no_gl()`	Context-loss recovery: clear handle without a GL call.