src/graphics/Canvas.cpp

   1 #include "Canvas.h"
   2
   3 #include <algorithm>
   4 #include <cassert>
   5 #include <stdexcept>
   6 #include <string>
   7
   8 using std::runtime_error;
   9
  10
  11 namespace space {
  12
  13 Canvas::Canvas(SDL_Window *win, int index, Uint32 flags)
  14 : canv(SDL_CreateRenderer(win, index, flags)) {
  15         if (!canv) {
  16                 throw runtime_error(std::string("create canvas: ") + SDL_GetError());
  17         }
  18 }
  19
  20 Canvas::~Canvas() {
  21         if (canv) SDL_DestroyRenderer(canv);
  22 }
  23
  24 Canvas::Canvas(Canvas &&other)
  25 : canv(other.canv) {
  26         other.canv = nullptr;
  27 }
  28
  29 Canvas &Canvas::operator =(Canvas &&other) {
  30         std::swap(canv, other.canv);
  31         return *this;
  32 }
  33
  34
  35 void Canvas::Present() {
  36         SDL_RenderPresent(canv);
  37 }
  38
  39
  40 Vector<int> Canvas::Size() const {
  41         assert(canv);
  42         Vector<int> size;
  43         SDL_GetRendererOutputSize(canv, &size.x, &size.y);
  44         return size;
  45 }
  46
  47
  48 void Canvas::SetColor(Color c) {
  49         SDL_SetRenderDrawColor(canv, c.r, c.g, c.b, c.a);
  50 }
  51
  52
  53 void Canvas::Fill() {
  54         SDL_RenderClear(canv);
  55 }
  56
  57 void Canvas::Outline() {
  58         SDL_RenderDrawRect(canv, nullptr);
  59 }
  60
  61
  62 void Canvas::Line(Vector<int> from, Vector<int> to) {
  63         SDL_RenderDrawLine(canv, from.x, from.y, to.x, to.y);
  64 }
  65
  66 void Canvas::FillRect(Vector<int> pos, Vector<int> size) {
  67         SDL_Rect destRect;
  68         destRect.x = pos.x;
  69         destRect.y = pos.y;
  70         destRect.w = size.x;
  71         destRect.h = size.y;
  72         SDL_RenderFillRect(canv, &destRect);
  73 }
  74
  75 void Canvas::OutlineRect(Vector<int> pos, Vector<int> size) {
  76         SDL_Rect destRect;
  77         destRect.x = pos.x;
  78         destRect.y = pos.y;
  79         destRect.w = size.x;
  80         destRect.h = size.y;
  81         SDL_RenderDrawRect(canv, &destRect);
  82 }
  83
  84
  85 void Canvas::Dot(Vector<int> pos) {
  86         SDL_RenderDrawPoint(canv, pos.x, pos.y);
  87 }
  88
  89 void Canvas::Cross(Vector<int> pos, int extent) {
  90         Line(
  91                 Vector<int>(pos.x - extent, pos.y),
  92                 Vector<int>(pos.x + extent, pos.y));
  93         Line(
  94                 Vector<int>(pos.x, pos.y - extent),
  95                 Vector<int>(pos.x, pos.y + extent));
  96 }
  97
  98
  99 namespace {
 100
 101 template<class Scalar>
 102 void GridImpl(
 103                 Canvas &canv,
 104                 Vector<int> pos,
 105                 Vector<int> size,
 106                 Vector<Scalar> step) {
 107         Vector<int> from(pos);
 108         Vector<int> to(pos + size);
 109         Vector<int> clip(canv.Size());
 110
 111         if (from.x > clip.x || from.y > clip.y || to.x < 0 || to.y < 0) {
 112                 return;
 113         }
 114         if (step.x <= 1 || step.y <= 1) {
 115                 canv.FillRect(pos, size);
 116                 return;
 117         }
 118
 119         if (from.x < -step.x) {
 120                 int skip = from.x / -step.x;
 121                 from.x += skip * step.x;
 122         }
 123         if (from.y < -step.y) {
 124                 int skip = from.y / -step.y;
 125                 from.y += skip * step.y;
 126         }
 127         if (to.x > clip.x + step.x) {
 128                 int skip = (to.x - clip.x) / step.x;
 129                 to.x -= skip * step.x;
 130         }
 131         if (to.y > clip.y + step.y) {
 132                 int skip = (to.y - clip.y) / step.y;
 133                 to.y -= skip * step.y;
 134         }
 135
 136         int width = to.x - from.x;
 137         int height = to.y - from.y;
 138
 139         for (Vector<Scalar> pos(from); pos.x <= to.x; pos.x += step.x) {
 140                 canv.Line(pos, Vector<int>(pos.x, pos.y + height));
 141         }
 142         for (Vector<Scalar> pos(from); pos.y <= to.y; pos.y += step.y) {
 143                 canv.Line(pos, Vector<int>(pos.x + width, pos.y));
 144         }
 145 }
 146
 147 template<class Scalar>
 148 void Grid2Impl(
 149                 Canvas &canv,
 150                 Vector<int> pos,
 151                 Vector<int> size,
 152                 Vector<Scalar> step,
 153                 Vector<int> n,
 154                 Color c1,
 155                 Color c2) {
 156         Vector<int> from(pos);
 157         Vector<int> to(pos + size);
 158         Vector<int> clip(canv.Size());
 159
 160         if (from.x > clip.x || from.y > clip.y || to.x < 0 || to.y < 0) {
 161                 return;
 162         }
 163         if (step.x <= 1 || step.y <= 1) {
 164                 canv.SetColor(c1);
 165                 canv.FillRect(pos, size);
 166                 canv.SetColor(c2);
 167                 GridImpl(canv, pos, size, step);
 168                 return;
 169         }
 170
 171         Vector<int> i(0, 0);
 172
 173         if (from.x < -step.x) {
 174                 int skip = from.x / -step.x;
 175                 from.x += skip * step.x;
 176                 i.x += skip;
 177         }
 178         if (from.y < -step.y) {
 179                 int skip = from.y / -step.y;
 180                 from.y += skip * step.y;
 181                 i.y += skip;
 182         }
 183         if (to.x > clip.x + step.x) {
 184                 int skip = (to.x - clip.x) / step.x;
 185                 to.x -= skip * step.x;
 186         }
 187         if (to.y > clip.y + step.y) {
 188                 int skip = (to.y - clip.y) / step.y;
 189                 to.y -= skip * step.y;
 190         }
 191
 192         int width = to.x - from.x;
 193         int height = to.y - from.y;
 194
 195         for (Vector<Scalar> pos(from); pos.x <= to.x; pos.x += step.x) {
 196                 canv.SetColor((i.x++ % n.x) ? c1 : c2);
 197                 canv.Line(pos, Vector<int>(pos.x, pos.y + height));
 198         }
 199         for (Vector<Scalar> pos(from); pos.y <= to.y; pos.y += step.y) {
 200                 canv.SetColor((i.y++ % n.y) ? c1 : c2);
 201                 canv.Line(pos, Vector<int>(pos.x + width, pos.y));
 202         }
 203 }
 204
 205 }
 206
 207 void Canvas::Grid(Vector<int> pos, Vector<int> size, Vector<int> step) {
 208         GridImpl(*this, pos, size, step);
 209 }
 210
 211 void Canvas::Grid(Vector<int> pos, Vector<int> size, Vector<float> step) {
 212         GridImpl(*this, pos, size, step);
 213 }
 214
 215 void Canvas::Grid2(
 216                 Vector<int> pos, Vector<int> size, Vector<int> step,
 217                 Vector<int> n, Color c1, Color c2) {
 218         Grid2Impl(*this, pos, size, step, n, c1, c2);
 219 }
 220
 221 void Canvas::Grid2(
 222                 Vector<int> pos, Vector<int> size, Vector<float> step,
 223                 Vector<int> n, Color c1, Color c2) {
 224         Grid2Impl(*this, pos, size, step, n, c1, c2);
 225 }
 226
 227 }