egutierrez
4610bb4a99
- cpp/functions/gfx/uniform_parser: regex-based parser of @slider/@color/@toggle/@xy annotations (+ inline tests) - cpp/functions/gfx/uniform_panel: ImGui widgets + value store + glUniform* apply - shader_canvas: optional uniforms callback invoked per-frame - gl_loader: +glUniform1i/3f/4f - seed plasma: demo uniforms u_speed + u_color - rebuild Windows .exe Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
65 lines
2.4 KiB
Markdown
65 lines
2.4 KiB
Markdown
---
|
|
name: shader_canvas
|
|
kind: component
|
|
lang: cpp
|
|
domain: gfx
|
|
version: "1.1.0"
|
|
purity: impure
|
|
signature: "void canvas_render(ShaderCanvas& c, float time_seconds, const std::function<void(unsigned int)>& uniforms_fn = {})"
|
|
description: "Componente ImGui que renderiza un fragment shader GLSL a un FBO y lo muestra en el panel actual. Compone gl_framebuffer, fullscreen_quad y gl_shader. Gestiona resize automático y coordenadas de mouse. Acepta callback opcional uniforms_fn invocado tras glUseProgram para uniforms custom."
|
|
tags: [opengl, shader, canvas, imgui, fbo, gfx, component]
|
|
uses_functions:
|
|
- gl_shader_cpp_gfx
|
|
- gl_framebuffer_cpp_gfx
|
|
- fullscreen_quad_cpp_gfx
|
|
- uniform_panel_cpp_gfx
|
|
uses_types: []
|
|
returns: []
|
|
returns_optional: false
|
|
error_type: "error_go_core"
|
|
imports: [imgui, GL/gl.h, GL/glext.h]
|
|
tested: false
|
|
tests: []
|
|
test_file_path: ""
|
|
file_path: "cpp/functions/gfx/shader_canvas.cpp"
|
|
framework: imgui
|
|
params:
|
|
- name: c
|
|
desc: "ShaderCanvas con estado GL interno (fb, quad, program). Inicializar con canvas_init() antes del primer frame."
|
|
- name: time_seconds
|
|
desc: "Tiempo en segundos para el uniform u_time. Usar ImGui::GetTime() o clock propio."
|
|
- name: uniforms_fn
|
|
desc: "Callback opcional invocado tras glUseProgram y antes de quad_draw. Recibe el program ID. Usar para aplicar uniforms custom (ej: uniforms_apply de uniform_panel)."
|
|
output: "Dibuja ImGui::Image con la textura del FBO renderizado. El panel ImGui debe estar abierto (entre Begin/End). Ocupa GetContentRegionAvail()."
|
|
---
|
|
|
|
# shader_canvas
|
|
|
|
Componente que encapsula el ciclo render-to-FBO + ImGui::Image. Llama a `canvas_render()` dentro de un `ImGui::Begin/End` activo.
|
|
|
|
## Ciclo de vida
|
|
|
|
```cpp
|
|
fn::gfx::ShaderCanvas canvas{};
|
|
|
|
// En el render loop:
|
|
if (!canvas.initialized) fn::gfx::canvas_init(canvas);
|
|
|
|
// Cargar un shader compilado:
|
|
auto r = fn::gfx::compile_fragment(src);
|
|
if (r.ok) fn::gfx::canvas_set_program(canvas, r.program);
|
|
|
|
// Dentro de ImGui::Begin/End:
|
|
fn::gfx::canvas_render(canvas, (float)ImGui::GetTime());
|
|
|
|
// Al destruir:
|
|
fn::gfx::canvas_destroy(canvas);
|
|
```
|
|
|
|
## Notas
|
|
|
|
- `canvas_set_program` borra el programa anterior automáticamente.
|
|
- `canvas_set_program(c, 0)` deja la pantalla en negro (glClear sin draw call).
|
|
- El flip de coordenadas UV (`ImVec2(0,1)` / `ImVec2(1,0)`) corrige el origen OpenGL bottom-left vs ImGui top-left.
|
|
- Guarda y restaura `GL_FRAMEBUFFER_BINDING` y `GL_VIEWPORT` para compatibilidad con el render loop de ImGui.
|