MyCustomGlObject.cpp

#include "MyCustomGlObject.h"
 
#include <ImFusion/Core/GL/FixedFunctionPipeline.h>
#include <ImFusion/Core/GL/VertexBuffer.h>
#include <ImFusion/Core/Mat.h>
 
#include <vector>
 
using namespace ImFusion;
 
void MyCustomGlObject::draw(const GlView& view)
{
    GL::FixedFunctionPipeline& ffp = GL::FixedFunctionPipeline::cachedInstance();

    // define vertex data on the CPU
    std::vector<vec3f> lineVertices{vec3f(-10.f, 10.f, 0.f), vec3f(10.f, 10.f, 0.f), vec3f(10.f, -10.f, 0.f)};
    // upload vertex data to the GPU using the utility function of GL::FixedFunctionPipeline.
    std::unique_ptr<GL::VertexBuffer> vbo = GL::FixedFunctionPipeline::makeVertexData(lineVertices);

    // Select the line rendering shader and initialize it with the GlViewState of the view passed as argument
    ffp.enable(view.state(), GL::FixedFunctionPipeline::ShaderSelection::LineRendering);
    // Set line color and width
    ffp.setDefaultColor(vec4(1.0, 0.5, 0.0, 1.0));
    ffp.setLineWidth(4);
 
    // When the shader is completely configured, issue the draw call on the vertex buffer
    vbo->draw(GL::Primitive::LineStrip);
 

    // define vertex data
    std::vector<vec3f> triangleVertices{vec3f(-10.f, 8.f, 0.f), vec3f(-10.f, -10.f, 0.f), vec3f(8.f, -10.f, 0.f)};
    std::vector<vec3f> triangleColors{vec3f(1.f, 0.f, 0.f), vec3f(0.f, 1.f, 0.f), vec3f(0.f, 0.f, 1.f)};
    // update the vertex buffer with the new data for the triangle
    GL::FixedFunctionPipeline::makeVertexData(triangleVertices).useColors(triangleColors).assign(*vbo);

    ffp.enable(view.state(), GL::FixedFunctionPipeline::ShaderSelection::Default);
    vbo->draw(GL::Primitive::Triangles);

    ffp.disable();
}