From 5e3a2492c7bb73daa4e27398daaf490d09980ff3 Mon Sep 17 00:00:00 2001
From: Jon Santmyer <jon@jonsantmyer.com>
Date: Wed, 22 Jun 2022 17:41:59 -0400
Subject: Base system viewer with data loaded from csv files

---
 src/camera.cpp | 197 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 197 insertions(+)
 create mode 100644 src/camera.cpp

(limited to 'src/camera.cpp')

diff --git a/src/camera.cpp b/src/camera.cpp
new file mode 100644
index 0000000..59e99a0
--- /dev/null
+++ b/src/camera.cpp
@@ -0,0 +1,197 @@
+#include "camera.hpp"
+#include "shape.hpp"
+#include <cmath>
+#include <algorithm>
+#include <variant>
+#include <typeinfo>
+#include <any>
+
+void 
+Camera::updateFrustum(){
+    if(m_dirty) {
+        *m_viewport << straw::clear(' ');
+        m_frustum = shapes::rectangle<long>(0, 0, (long)m_viewport->getwidth(), (long)m_viewport->getheight());
+        m_frustum.position -= (m_frustum.bounds / 2);
+        m_frustum.position += m_position + m_origin;
+        m_dirty = false;
+    }
+}
+
+void
+RenderBatchEntry::translate(Camera *camera)
+{
+    std::visit([camera](auto &shapeval) {
+        shapeval.translate(-camera->m_frustum.position);
+        shapeval.translate((camera->m_frustum.bounds * camera->m_scale) / 2);
+        shapeval.position = vex::vec2<long>(
+                (long)std::floor((double)shapeval.position[0] / (double)camera->m_scale),
+                (long)std::floor((double)shapeval.position[1] / (double)camera->m_scale));
+        shapeval.scale(camera->m_scale);
+        }, shape);
+}
+
+void 
+Camera::draw()
+{
+    if(!m_dirty) return;
+    updateFrustum();
+    shapes::rectangle<long> ssfrustum{vex::vec2<long>(0, 0), vex::vec2<long>(m_viewport->getwidth(), m_viewport->getheight())};
+
+    //Remove all batches not intersecting the screenspace frustum
+    m_shapeBatch.erase(
+            std::remove_if(
+                m_shapeBatch.begin(), 
+                m_shapeBatch.end(),
+                [ssfrustum, this](RenderBatchEntry &entry){
+                    entry.translate(this);
+                    return std::visit([ssfrustum](auto &&shape) {
+                        return shapes::intersects(shape, ssfrustum) == 0;
+                    }, entry.shape);
+                }),
+            m_shapeBatch.end());
+    for(RenderBatchEntry &entry : m_shapeBatch) entry.plot(this);
+    m_shapeBatch.clear();
+}
+
+void
+RenderBatchEntry::plotPoint(shapes::point<long> point, Camera *camera) {
+    long ploty = camera->m_viewport->getheight() - point.position[1];
+    if(point.position[0] < 0 || point.position[0] >= camera->m_viewport->getwidth() ||
+            ploty < 0 || ploty >= camera->m_viewport->getheight()) return;
+    *camera->m_viewport << straw::setcolor(fg, bg) << straw::plot(point.position[0], ploty, c);
+}
+
+void
+RenderBatchEntry::plotLine(shapes::line<long> line, Camera *camera) {
+    if(line.end == line.position) {
+        plotPoint(shapes::point<long>(line.position), camera);
+    }
+    vex::vec2<long> vpdim(camera->m_viewport->getwidth(),
+                          camera->m_viewport->getheight());
+    vex::vec2<long> d(line.end - line.position);
+    long adx = std::abs(d[0]);
+    long ady = std::abs(d[1]);
+
+    long offX= d[0] > 0 ? 1 : -1;
+    long offY = d[1] > 0 ? 1 : -1;
+
+    *camera->m_viewport << straw::setcolor(fg, bg);
+    if(adx < ady) {
+        long err = ady / 2;
+        long x = line.position[0];
+        long y = line.position[1];
+        for(long i = 0; i < ady; i++) {
+            if(x > 0 && x < vpdim[0] && y > 0 && y < vpdim[1]) {
+                long ploty = vpdim[1] - y;
+                *camera->m_viewport << straw::plot(x, ploty, c);
+            }
+            if(err >= ady) {
+                x += offX;
+                y += offY;
+                err += adx - ady;
+            }else {
+                y += offY;
+                err += adx;
+            }
+        }
+
+    }else{
+        long err = adx / 2;
+        long x = line.position[0];
+        long y = line.position[1];
+        for(long i = 0; i < adx; i++) {
+            if(x > 0 && x < vpdim[0] && y > 0 && y < vpdim[1]) {
+                long ploty = vpdim[1] - y;
+                *camera->m_viewport << straw::plot(x, ploty, c);
+            }
+            if(err >= adx) {
+                x += offX;
+                y += offY;
+                err += ady - adx;
+            }else {
+                x += offX;
+                err += ady;
+            }
+        }
+    }
+}
+
+void
+RenderBatchEntry::plotCircle(shapes::circle<long> circle, Camera *camera) {
+    if(circle.radius == 1) {
+        plotPoint(shapes::point<long>(circle.position), camera);
+        return;
+    }
+    long sy = std::max<long>(1, circle.position[1] - circle.radius);
+    long ey = std::min<long>(camera->m_viewport->getheight(), circle.position[1] + circle.radius);
+    *camera->m_viewport << straw::setcolor(fg, bg);
+    for(long y = sy; y <= ey; y++) {
+        long ploty = camera->m_viewport->getheight() - y;
+        long r2 = circle.radius * circle.radius;
+        long dy = circle.position[1] - y;
+        long dx = (long)std::sqrt(r2 - (dy * dy));
+        long sx = std::max<long>(0, circle.position[0] - dx + 1);
+        long ex = std::min<long>(camera->m_viewport->getwidth(), circle.position[0] + dx);
+        for(unsigned x = (unsigned)sx; x < ex; x++) {
+            *camera->m_viewport << straw::plot(x, ploty, c);
+        }
+    }
+}
+
+void
+RenderBatchEntry::plotRectangle(shapes::rectangle<long> rectangle, Camera *camera)
+{
+    if(rectangle.bounds[1] == 1) {
+        plotPoint(shapes::point<long>(rectangle.position), camera);
+        return;
+    }
+    long sy = std::max<long>(1, rectangle.position[1]);
+    long ey = std::min<long>(camera->m_viewport->getheight(), rectangle.position[1] + rectangle.bounds[1]);
+    *camera->m_viewport << straw::setcolor(fg, bg);
+    for(long y = sy; y < ey; y++) {
+        long ploty = camera->m_viewport->getheight() - y;
+        long sx = std::max<long>(0, rectangle.position[1]);
+        long ex = std::min<long>(camera->m_viewport->getwidth(), rectangle.position[1] + rectangle.bounds[1]);
+        for(unsigned x = (unsigned)sx; x < ex; x++) {
+            *camera->m_viewport << straw::plot(x, ploty, c);
+        }
+    }
+}
+
+void
+RenderBatchEntry::plotEllipse(shapes::ellipse<long> shapeval, Camera *camera) {
+    if(shapeval.a == 1) {
+        plotPoint(shapes::point<long>(shapeval.position), camera);
+        return;
+    }
+    long sy = std::max<long>(1, shapeval.position[1] - shapeval.b);
+    long ey = std::min<long>(camera->m_viewport->getheight(), shapeval.position[1] + shapeval.b);
+    *camera->m_viewport << straw::setcolor(fg, bg);
+    for(long y = sy; y <= ey; y++) {
+        long ploty = camera->m_viewport->getheight() - y;
+        long dy = shapeval.position[1] - y;
+        long dy2 = dy * dy;
+        long a2 = shapeval.a * shapeval.a;
+        long b2 = shapeval.b * shapeval.b;
+        long dx = (long)(((2.0 * (double)shapeval.a) /
+                    (double)shapeval.b) * std::sqrt(b2 - dy2) / 2.0);
+        long sx = std::max<long>(0, shapeval.position[0] - dx + 1);
+        long ex = std::min<long>(camera->m_viewport->getwidth(), shapeval.position[0] + dx);
+
+        for(unsigned x = (unsigned)sx; x < ex; x++) {
+            *camera->m_viewport << straw::plot(x, ploty, c);
+        }       
+    }
+}
+void
+RenderBatchEntry::plot(Camera *camera) 
+{
+    std::visit([this, camera](auto &shapeval) -> void{
+        using T = std::decay_t<decltype(shapeval)>;
+        if constexpr(std::is_same_v<T, shapes::point<long>>) plotPoint(shapeval, camera);
+        if constexpr(std::is_same_v<T, shapes::line<long>>) plotLine(shapeval, camera);
+        if constexpr(std::is_same_v<T, shapes::ellipse<long>>) plotEllipse(shapeval, camera);
+        if constexpr(std::is_same_v<T, shapes::circle<long>>) plotCircle(shapeval, camera);
+        if constexpr(std::is_same_v<T, shapes::rectangle<long>>) plotRectangle(shapeval, camera);
+    }, shape);
+}
-- 
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