Method render

src/host/stage_view.cpp:101–129

}

GLuint StageView::render(Stage& stage) const {
    if (fbo_ == 0) {
        return 0;
    }

    canvas_.glBindFramebuffer(GL_FRAMEBUFFER, fbo_);
    canvas_.glViewport(0, 0, width_, height_);
    canvas_.glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
    canvas_.glClear(GL_COLOR_BUFFER_BIT);

    // A VAO must be bound for the viz layer's glDrawArrays calls to produce
    // output in a core-profile context; bind ours each frame since ImGui's
    // backend rebinds/clears the VAO binding when it renders.
    // Enable alpha blending for this pass so the pixel-value text overlay
    // (glyph coverage lives in the fragment alpha) composites over the buffer
    // instead of painting opaque glyph-quad boxes. Set every frame: ImGui's GL
    // backend saves/restores blend state around its own render and leaves it
    // disabled between our passes (same reason the VAO is rebound above).
    canvas_.glEnable(GL_BLEND);
    canvas_.glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

    canvas_.glBindVertexArray(vao_);
    stage.update();
    stage.draw();
    canvas_.glBindVertexArray(0);

    canvas_.glBindFramebuffer(GL_FRAMEBUFFER, 0);
    return texture_;
}

} // namespace oid::host