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Make VisibleRegion more GL2-friendly

pull/3/head
Hleb Valoshka 2019-07-07 12:29:31 +03:00
parent 96c22fbe8e
commit a1bdca280a
1 changed files with 45 additions and 6 deletions
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51
src/celengine/visibleregion.cpp
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@ -15,6 +15,7 @@
#include "body.h"
#include "selection.h"
#include "vecgl.h"
#include "vertexobject.h"
#include <celmath/intersect.h>
#include <Eigen/Core>
#include <Eigen/Geometry>
@ -130,9 +131,47 @@ ellipsoidTangent(const Matrix<T, 3, 1>& recipSemiAxes,
return e + v * t1;
}
constexpr const unsigned maxSections = 360;
static void
renderTerminator(Renderer* renderer, const vector<Vector3f>& pos, const Vector4f& color, const Quaternionf& qf)
{
/*!
* Proper terminator calculation requires double precision floats in GLSL
* which were introduced in ARB_gpu_shader_fp64 unavailable with GL2.1.
* Because of this we make calculations on a CPU and stream results to GPU.
*/
static celgl::VertexObject vo{ GL_ARRAY_BUFFER, maxSections * sizeof(Vector3f), GL_DYNAMIC_DRAW };
auto *prog = renderer->getShaderManager().getShader("uniform_color");
if (prog == nullptr)
return;
vo.bindWritable();
if (!vo.initialized())
{
vo.allocate();
vo.setVertices(3, GL_FLOAT);
}
vo.setBufferData(pos.data(), 0, pos.size() * sizeof(Vector3f));
prog->use();
prog->vec4Param("color") = color;
Eigen::Matrix4f m = Eigen::Matrix4f::Identity();
m.topLeftCorner(3, 3) = qf.conjugate().toRotationMatrix();
prog->mat4Param("rotate") = m;
vo.draw(GL_LINE_LOOP, pos.size());
vo.unbind();
glUseProgram(0);
}
void
VisibleRegion::render(Renderer* /* renderer */,
VisibleRegion::render(Renderer* renderer,
const Vector3f& /* pos */,
float discSizeInPixels,
double tdb) const
@ -157,7 +196,7 @@ VisibleRegion::render(Renderer* /* renderer */,
// Base the amount of subdivision on the apparent size
auto nSections = (unsigned int) (30.0f + discSizeInPixels * 0.5f);
nSections = min(nSections, 360u);
nSections = min(nSections, maxSections);
Quaterniond q = m_body.getEclipticToBodyFixed(tdb);
Quaternionf qf = q.cast<float>();
@ -211,8 +250,8 @@ VisibleRegion::render(Renderer* /* renderer */,
Vector3d e_ = e.cwiseProduct(recipSemiAxes);
double ee = e_.squaredNorm();
glColor4f(m_color.red(), m_color.green(), m_color.blue(), opacity);
glBegin(GL_LINE_LOOP);
vector<Vector3f> pos;
pos.reserve(nSections);
for (unsigned i = 0; i < nSections; i++)
{
@ -221,10 +260,10 @@ VisibleRegion::render(Renderer* /* renderer */,
Vector3d toCenter = ellipsoidTangent(recipSemiAxes, w, e, e_, ee);
toCenter *= maxSemiAxis * scale;
glVertex3dv(toCenter.data());
pos.push_back(toCenter.cast<float>());
}
glEnd();
renderTerminator(renderer, pos, Color(m_color, opacity).toVector4(), qf);
glPopMatrix();