src/objectrenderer.cpp

   1 /**
   2  * @file objectrenderer.cpp
   3  * @brief Implements ObjectRenderer and derived classes
   4  */
   5
   6 #include "objectrenderer.h"
   7 #include "view.h"
   8 #include <vector>
   9 #include <queue>
  10 #include <stack>
  11
  12 using namespace std;
  13
  14 namespace IPDF
  15 {
  16
  17 /**
  18  * ObjectRenderer constructor
  19  * Note we cannot compile the shaders in the ShaderProgram constructor
  20  *  because the Screen class needs to initialise GL first and it has a
  21  *      ShaderProgram member
  22  */
  23 ObjectRenderer::ObjectRenderer(const ObjectType & type,
  24                 const char * vert_glsl_file, const char * frag_glsl_file, const char * geom_glsl_file)
  25                 : m_type(type), m_shader_program(), m_indexes(), m_buffer_builder(NULL)
  26 {
  27         m_shader_program.InitialiseShaders(vert_glsl_file, frag_glsl_file, geom_glsl_file);
  28         m_shader_program.Use();
  29         glUniform4f(m_shader_program.GetUniformLocation("colour"), 0,0,0,1); //TODO: Allow different colours
  30 }
  31
  32 /**
  33  * Render using GPU
  34  */
  35 void ObjectRenderer::RenderUsingGPU(unsigned first_obj_id, unsigned last_obj_id)
  36 {
  37         // If we don't have anything to render, return.
  38         if (first_obj_id == last_obj_id) return;
  39         // If there are no objects of this type, return.
  40         if (m_indexes.empty()) return;
  41         unsigned first_index = 0;
  42         while (m_indexes.size() > first_index && m_indexes[first_index] < first_obj_id) first_index ++;
  43         unsigned last_index = first_index;
  44         while (m_indexes.size() > last_index && m_indexes[last_index] < last_obj_id) last_index ++;
  45
  46         m_shader_program.Use();
  47         m_ibo.Bind();
  48         glDrawElements(GL_LINES, (last_index-first_index)*2, GL_UNSIGNED_INT, (GLvoid*)(2*first_index*sizeof(uint32_t)));
  49 }
  50
  51
  52 /**
  53  * Default implementation for rendering using CPU
  54  */
  55 void ObjectRenderer::RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id)
  56 {
  57         Error("Cannot render objects of type %d on CPU", m_type);
  58         //TODO: Render a rect or something instead?
  59 }
  60
  61 /**
  62  * Prepare index buffers for both CPU and GPU rendering to receive indexes (but don't add any yet!)
  63  */
  64 void ObjectRenderer::PrepareBuffers(unsigned max_objects)
  65 {
  66         if (m_buffer_builder != NULL) // We already have a BufferBuilder
  67         {
  68                 Fatal("Has been called before, without FinaliseBuffers being called since!");
  69         }
  70         // Empty and reserve the indexes vector (for CPU rendering)
  71         m_indexes.clear();
  72         m_indexes.reserve(max_objects); //TODO: Can probably make this smaller? Or leave it out? Do we care?
  73
  74         // Initialise and resize the ibo (for GPU rendering)
  75         m_ibo.Invalidate();
  76         m_ibo.SetUsage(GraphicsBuffer::BufferUsageStaticDraw);
  77         m_ibo.SetType(GraphicsBuffer::BufferTypeIndex);
  78         m_ibo.Resize(max_objects * 2 * sizeof(uint32_t));
  79         // BufferBuilder is used to construct the ibo
  80         m_buffer_builder = new BufferBuilder<uint32_t>(m_ibo.Map(false, true, true), m_ibo.GetSize()); // new matches delete in ObjectRenderer::FinaliseBuffers
  81
  82 }
  83
  84 /**
  85  * Add object index to the buffers for CPU and GPU rendering
  86  */
  87 void ObjectRenderer::AddObjectToBuffers(unsigned index)
  88 {
  89         if (m_buffer_builder == NULL) // No BufferBuilder!
  90         {
  91                 Fatal("Called without calling PrepareBuffers");
  92         }
  93         m_buffer_builder->Add(2*index); // ibo for GPU rendering
  94         m_buffer_builder->Add(2*index+1);
  95         m_indexes.push_back(index); // std::vector of indices for CPU rendering
  96 }
  97
  98 /**
  99  * Finalise the index buffers for CPU and GPU rendering
 100  */
 101 void ObjectRenderer::FinaliseBuffers()
 102 {
 103         if (m_buffer_builder == NULL) // No BufferBuilder!
 104         {
 105                 Fatal("Called without calling PrepareBuffers");
 106         }
 107         // For GPU rendering, UnMap the ibo
 108         m_ibo.UnMap();
 109         // ... and delete the BufferBuilder used to create it
 110         delete m_buffer_builder; // delete matches new in ObjectRenderer::PrepareBuffers
 111         m_buffer_builder = NULL;
 112
 113         // Nothing is necessary for CPU rendering
 114 }
 115
 116
 117 /**
 118  * Rectangle (filled)
 119  */
 120 void RectFilledRenderer::RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id)
 121 {
 122         for (unsigned i = 0; i < m_indexes.size(); ++i)
 123         {
 124                 if (m_indexes[i] < first_obj_id) continue;
 125                 if (m_indexes[i] >= last_obj_id) continue;
 126                 PixelBounds bounds(CPURenderBounds(objects.bounds[m_indexes[i]], view, target));
 127                 FloodFillOnCPU(bounds.x+1, bounds.y+1, bounds, target, Colour(0,0,0,1));
 128                 /*
 129                 for (int64_t x = max((int64_t)0, bounds.x); x <= min(bounds.x+bounds.w, target.w-1); ++x)
 130                 {
 131                         for (int64_t y = max((int64_t)0, bounds.y); y <= min(bounds.y+bounds.h, target.h-1); ++y)
 132                         {
 133                                 int index = (x+target.w*y)*4;
 134                                 target.pixels[index+0] = 0;
 135                                 target.pixels[index+1] = 0;
 136                                 target.pixels[index+2] = 0;
 137                                 target.pixels[index+3] = 255;
 138                         }
 139                 }
 140                 */
 141         }
 142 }
 143
 144 /**
 145  * Rectangle (outine)
 146  */
 147 void RectOutlineRenderer::RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id)
 148 {
 149         //Debug("Render %u outlined rectangles on CPU", m_indexes.size());
 150         for (unsigned i = 0; i < m_indexes.size(); ++i)
 151         {
 152                 if (m_indexes[i] < first_obj_id) continue;
 153                 if (m_indexes[i] >= last_obj_id) continue;
 154                 PixelBounds bounds(CPURenderBounds(objects.bounds[m_indexes[i]], view, target));
 155
 156                 // Using bresenham's lines now mainly because I want to see if they work
 157                 // top
 158                 ObjectRenderer::RenderLineOnCPU(bounds.x, bounds.y, bounds.x+bounds.w, bounds.y, target);
 159                 // bottom
 160                 ObjectRenderer::RenderLineOnCPU(bounds.x, bounds.y+bounds.h, bounds.x+bounds.w, bounds.y+bounds.h, target);
 161                 // left
 162                 ObjectRenderer::RenderLineOnCPU(bounds.x, bounds.y, bounds.x, bounds.y+bounds.h, target);
 163                 // right
 164                 ObjectRenderer::RenderLineOnCPU(bounds.x+bounds.w, bounds.y, bounds.x+bounds.w, bounds.y+bounds.h, target);
 165
 166                 // Diagonal for testing (from bottom left to top right)
 167                 //ObjectRenderer::RenderLineOnCPU(bounds.x,bounds.y+bounds.h, bounds.x+bounds.w, bounds.y,target, C_BLUE);
 168                 //ObjectRenderer::RenderLineOnCPU(bounds.x+bounds.w, bounds.y+bounds.h, bounds.x, bounds.y, target,C_GREEN);
 169         }
 170 }
 171
 172 /**
 173  * Circle (filled)
 174  */
 175 void CircleFilledRenderer::RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id)
 176 {
 177         for (unsigned i = 0; i < m_indexes.size(); ++i)
 178         {
 179                 if (m_indexes[i] < first_obj_id) continue;
 180                 if (m_indexes[i] >= last_obj_id) continue;
 181                 PixelBounds bounds(CPURenderBounds(objects.bounds[m_indexes[i]], view, target));
 182                 int64_t centre_x = bounds.x + bounds.w / 2;
 183                 int64_t centre_y = bounds.y + bounds.h / 2;
 184
 185                 //Debug("Centre is %d, %d", centre_x, centre_y);
 186                 //Debug("Bounds are %d,%d,%d,%d", bounds.x, bounds.y, bounds.w, bounds.h);
 187                 //Debug("Windos is %d,%d", target.w, target.h);
 188                 for (int64_t x = max((int64_t)0, bounds.x); x <= min(bounds.x+bounds.w, target.w-1); ++x)
 189                 {
 190                         for (int64_t y = max((int64_t)0, bounds.y); y <= min(bounds.y + bounds.h, target.h-1); ++y)
 191                         {
 192                                 Real dx(2); dx *= Real(x - centre_x)/Real(bounds.w);
 193                                 Real dy(2); dy *= Real(y - centre_y)/Real(bounds.h);
 194                                 int64_t index = (x+target.w*y)*4;
 195
 196                                 if (dx*dx + dy*dy <= Real(1))
 197                                 {
 198                                         target.pixels[index+0] = 0;
 199                                         target.pixels[index+1] = 0;
 200                                         target.pixels[index+2] = 0;
 201                                         target.pixels[index+3] = 255;
 202                                 }
 203                         }
 204                 }
 205         }
 206 }
 207
 208 Rect ObjectRenderer::CPURenderBounds(const Rect & bounds, const View & view, const CPURenderTarget & target)
 209 {
 210         Rect result = view.TransformToViewCoords(bounds);
 211         result.x *= Real(target.w);
 212         result.y *= Real(target.h);
 213         result.w *= Real(target.w);
 214         result.h *= Real(target.h);
 215         return result;
 216 }
 217
 218 ObjectRenderer::PixelPoint ObjectRenderer::CPUPointLocation(const Vec2 & point, const View & view, const CPURenderTarget & target)
 219 {
 220         // hack...
 221         Rect result = view.TransformToViewCoords(Rect(point.x, point.y,1,1));
 222         int64_t x = Int64(result.x)*target.w;
 223         int64_t y = Int64(result.y)*target.h;
 224         return PixelPoint(x,y);
 225 }
 226
 227
 228 void BezierRenderer::RenderBezierOnCPU(unsigned i, Objects & objects, const View & view, const CPURenderTarget & target, const Colour & c)
 229 {
 230         const Rect & bounds = objects.bounds[i];
 231         PixelBounds pix_bounds(CPURenderBounds(bounds,view,target));
 232         Bezier control(objects.beziers[objects.data_indices[i]].ToAbsolute(bounds),CPURenderBounds(Rect(0,0,1,1), view, target));
 233
 234         if (view.ShowingBezierBounds())
 235         {
 236                 ObjectRenderer::RenderLineOnCPU(pix_bounds.x, pix_bounds.y, pix_bounds.x+pix_bounds.w, pix_bounds.y, target, Colour(255,0,0,0));
 237                 ObjectRenderer::RenderLineOnCPU(pix_bounds.x, pix_bounds.y+pix_bounds.h, pix_bounds.x+pix_bounds.w, pix_bounds.y+pix_bounds.h, target, Colour(0,255,0,0));
 238                 ObjectRenderer::RenderLineOnCPU(pix_bounds.x, pix_bounds.y, pix_bounds.x, pix_bounds.y+pix_bounds.h, target, Colour(255,0,0,0));
 239                 ObjectRenderer::RenderLineOnCPU(pix_bounds.x+pix_bounds.w, pix_bounds.y, pix_bounds.x+pix_bounds.w, pix_bounds.y+pix_bounds.h, target, Colour(0,255,0,0));
 240         }
 241
 242         unsigned blen = target.w;//min(max(2U, (unsigned)Int64(Real(target.w)/view.GetBounds().w)),
 243                         //min((unsigned)(pix_bounds.w+pix_bounds.h)/4 + 1, 100U));
 244
 245                 // DeCasteljau Divide the Bezier
 246         queue<Bezier> divisions;
 247         divisions.push(control);
 248         while(divisions.size() < blen)
 249         {
 250                 Bezier & current = divisions.front();
 251                 if (current.GetType() == Bezier::LINE)
 252                 {
 253                         --blen;
 254                         continue;
 255                 }
 256                 divisions.push(current.DeCasteljauSubdivideRight(Real(1)/Real(2)));
 257                 divisions.push(current.DeCasteljauSubdivideLeft(Real(1)/Real(2)));
 258                 divisions.pop();
 259         }
 260         while (divisions.size() > 0)
 261         {
 262                 Bezier & current = divisions.front();
 263                 RenderLineOnCPU(Int64(current.x0), Int64(current.y0), Int64(current.x3), Int64(current.y3), target, c);
 264                 divisions.pop();
 265         }
 266 }
 267
 268 /**
 269  * Bezier curve
 270  * Not sure how to apply De'Casteljau, will just use a bunch of Bresnham lines for now.
 271  */
 272 void BezierRenderer::RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id)
 273 {
 274         if (view.PerformingShading())
 275                 return;
 276
 277         //Warn("Rendering Beziers on CPU. Things may explode.");
 278         for (unsigned i = 0; i < m_indexes.size(); ++i)
 279         {
 280                 if (m_indexes[i] < first_obj_id) continue;
 281                 if (m_indexes[i] >= last_obj_id) continue;
 282                 Colour c(0,0,0,255);
 283                 if (view.ShowingBezierType())
 284                 {
 285                         switch (objects.beziers[objects.data_indices[m_indexes[i]]].GetType())
 286                         {
 287                                 case Bezier::LINE:
 288                                         break;
 289                                 case Bezier::QUADRATIC:
 290                                         c.b = 255;
 291                                         break;
 292                                 case Bezier::SERPENTINE:
 293                                         c.r = 255;
 294                                         break;
 295                                 case Bezier::CUSP:
 296                                         c.g = 255;
 297                                         break;
 298                                 case Bezier::LOOP:
 299                                         c.r = 128;
 300                                         c.b = 128;
 301                                         break;
 302                                 default:
 303                                         c.r = 128;
 304                                         c.g = 128;
 305                                         break;
 306                         }
 307                 }
 308                 RenderBezierOnCPU(m_indexes[i], objects, view, target, c);
 309         }
 310 }
 311
 312 void BezierRenderer::PrepareBezierGPUBuffer(Objects & objects)
 313 {
 314         m_bezier_coeffs.SetType(GraphicsBuffer::BufferTypeTexture);
 315         m_bezier_coeffs.SetUsage(GraphicsBuffer::BufferUsageDynamicDraw);
 316         m_bezier_coeffs.Resize(objects.beziers.size()*sizeof(GPUBezierCoeffs));
 317         BufferBuilder<GPUBezierCoeffs> builder(m_bezier_coeffs.Map(false, true, true), m_bezier_coeffs.GetSize());
 318
 319
 320         for (unsigned i = 0; i < objects.beziers.size(); ++i)
 321         {
 322                 const Bezier & bez = objects.beziers[i];
 323
 324                 GPUBezierCoeffs coeffs = {
 325                         Float(bez.x0), Float(bez.y0),
 326                         Float(bez.x1), Float(bez.y1),
 327                         Float(bez.x2), Float(bez.y2),
 328                         Float(bez.x3), Float(bez.y3)
 329                         };
 330                 builder.Add(coeffs);
 331         }
 332         m_bezier_coeffs.UnMap();
 333         glGenTextures(1, &m_bezier_buffer_texture);
 334         glBindTexture(GL_TEXTURE_BUFFER, m_bezier_buffer_texture);
 335         glTexBuffer(GL_TEXTURE_BUFFER, GL_RG32F, m_bezier_coeffs.GetHandle());
 336
 337         m_bezier_ids.SetType(GraphicsBuffer::BufferTypeTexture);
 338         m_bezier_ids.SetUsage(GraphicsBuffer::BufferUsageDynamicDraw);
 339         m_bezier_ids.Upload(objects.data_indices.size() * sizeof(uint32_t), &objects.data_indices[0]);
 340
 341         glGenTextures(1, &m_bezier_id_buffer_texture);
 342         glActiveTexture(GL_TEXTURE1);
 343         glBindTexture(GL_TEXTURE_BUFFER, m_bezier_id_buffer_texture);
 344         glTexBuffer(GL_TEXTURE_BUFFER, GL_R32I, m_bezier_ids.GetHandle());
 345         glActiveTexture(GL_TEXTURE0);
 346 }
 347
 348 void BezierRenderer::RenderUsingGPU(unsigned first_obj_id, unsigned last_obj_id)
 349 {
 350         if (!m_shader_program.Valid())
 351                 Warn("Shader is invalid (objects are of type %d)", m_type);
 352
 353         // If we don't have anything to render, return.
 354         if (first_obj_id == last_obj_id) return;
 355         // If there are no objects of this type, return.
 356         if (m_indexes.empty()) return;
 357
 358         unsigned first_index = 0;
 359         while (m_indexes.size() > first_index && m_indexes[first_index] < first_obj_id) first_index ++;
 360         unsigned last_index = first_index;
 361         while (m_indexes.size() > last_index && m_indexes[last_index] < last_obj_id) last_index ++;
 362
 363         m_shader_program.Use();
 364         glUniform1i(m_shader_program.GetUniformLocation("bezier_buffer_texture"), 0);
 365         glUniform1i(m_shader_program.GetUniformLocation("bezier_id_buffer_texture"), 1);
 366         m_ibo.Bind();
 367         glDrawElements(GL_LINES, (last_index-first_index)*2, GL_UNSIGNED_INT, (GLvoid*)(2*first_index*sizeof(uint32_t)));
 368 }
 369
 370
 371
 372 /**
 373  * Render Path (shading)
 374  */
 375 void PathRenderer::RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id)
 376 {
 377
 378
 379         for (unsigned i = 0; i < m_indexes.size(); ++i)
 380         {
 381                 if (m_indexes[i] < first_obj_id) continue;
 382                 if (m_indexes[i] >= last_obj_id) continue;
 383
 384
 385                 Rect bounds(CPURenderBounds(objects.bounds[m_indexes[i]], view, target));
 386                 PixelBounds pix_bounds(bounds);
 387                 Path & path = objects.paths[objects.data_indices[m_indexes[i]]];
 388
 389                 if (view.ShowingFillPoints())
 390                 {
 391
 392                         PixelPoint start(CPUPointLocation((path.m_top+path.m_left+path.m_right+path.m_bottom)/4, view, target));
 393                         for (unsigned f = 0; f < path.m_fill_points.size(); ++f)
 394                         {
 395                                 PixelPoint end(CPUPointLocation(path.m_fill_points[f], view, target));
 396                                 RenderLineOnCPU(start.first, start.second, end.first, end.second, target, Colour(0,0,255,0));
 397                         }
 398                 }
 399
 400                 if (!view.PerformingShading())
 401                         continue;
 402
 403                 for (unsigned b = path.m_start; b <= path.m_end; ++b)
 404                 {
 405                         BezierRenderer::RenderBezierOnCPU(b,objects,view,target,path.m_stroke);
 406                 }
 407
 408                 if (pix_bounds.w*pix_bounds.h > 100)
 409                 {
 410                         vector<Vec2> & fill_points = path.FillPoints(objects, view);
 411                         Debug("High resolution; use fill points %u,%u", pix_bounds.w, pix_bounds.h);
 412                         for (unsigned f = 0; f < fill_points.size(); ++f)
 413                         {
 414                                 PixelPoint fill_point(CPUPointLocation(fill_points[f], view, target));
 415
 416                                 FloodFillOnCPU(fill_point.first, fill_point.second, pix_bounds, target, path.m_fill, path.m_stroke);
 417                         }
 418                 }
 419                 else
 420                 {
 421                         Debug("Low resolution; use brute force %u,%u",pix_bounds.w, pix_bounds.h);
 422                         int64_t y_min = max((int64_t)0, pix_bounds.y);
 423                         int64_t y_max = min(pix_bounds.y+pix_bounds.h, target.h);
 424                         int64_t x_min = max((int64_t)0, pix_bounds.x);
 425                         int64_t x_max = min(pix_bounds.x+pix_bounds.w, target.w);
 426                         for (int64_t y = y_min; y < y_max; ++y)
 427                         {
 428                                 for (int64_t x = x_min; x < x_max; ++x)
 429                                 {
 430                                         Rect pb(path.SolveBounds(objects));
 431                                         Vec2 pt(pb.x + (Real(x-pix_bounds.x)/Real(pix_bounds.w))*pb.w,
 432                                                         pb.y + (Real(y-pix_bounds.y)/Real(pix_bounds.h))*pb.h);
 433                                         if (path.PointInside(objects, pt))
 434                                         {
 435                                                 FloodFillOnCPU(x, y, pix_bounds, target, path.m_fill, path.m_stroke);
 436                                         }
 437                                 }
 438                         }
 439                 }
 440         }
 441 }
 442
 443 /**
 444  * For debug, save pixels to bitmap
 445  */
 446 void ObjectRenderer::SaveBMP(const CPURenderTarget & target, const char * filename)
 447 {
 448         SDL_Surface * surf = SDL_CreateRGBSurfaceFrom(target.pixels, target.w, target.h, 8*4, target.w*4,
 449         #if SDL_BYTEORDER == SDL_LIL_ENDIAN
 450                 0x000000ff, 0x0000ff00, 0x00ff0000, 0xff000000
 451         #else
 452                 0xff000000, 0x00ff0000, 0x0000ff00, 0x000000ff
 453         #endif //SDL_BYTEORDER
 454         );
 455         if (surf == NULL)
 456                 Fatal("SDL_CreateRGBSurfaceFrom(pixels...) failed - %s", SDL_GetError());
 457         if (SDL_SaveBMP(surf, filename) != 0)
 458                 Fatal("SDL_SaveBMP failed - %s", SDL_GetError());
 459
 460         // Cleanup
 461         SDL_FreeSurface(surf);
 462 }
 463
 464 /**
 465  * Bresenham's lines
 466  */
 467 void ObjectRenderer::RenderLineOnCPU(int64_t x0, int64_t y0, int64_t x1, int64_t y1, const CPURenderTarget & target, const Colour & colour, bool transpose)
 468 {
 469         int64_t dx = x1 - x0;
 470         int64_t dy = y1 - y0;
 471         bool neg_m = (dy*dx < 0);
 472         dy = abs(dy);
 473         dx = abs(dx);
 474
 475         // If positive slope > 1, just swap x and y
 476         if (dy > dx)
 477         {
 478                 RenderLineOnCPU(y0,x0,y1,x1,target,colour,!transpose);
 479                 return;
 480         }
 481
 482         int64_t two_dy = 2*dy;
 483         int64_t p = two_dy - dx;
 484         int64_t two_dxdy = 2*(dy-dx);
 485         int64_t x; int64_t y; int64_t x_end;
 486         int64_t width = (transpose ? target.h : target.w);
 487         int64_t height = (transpose ? target.w : target.h);
 488
 489         if (x0 > x1)
 490         {
 491                 x = x1;
 492                 y = y1;
 493                 x_end = x0;
 494         }
 495         else
 496         {
 497                 x = x0;
 498                 y = y0;
 499                 x_end = x1;
 500         }
 501
 502         if (x < 0)
 503         {
 504                 if (x_end < 0) return;
 505                 y = (neg_m ? y - (dy*-x)/dx : y + (dy*-x)/dx);
 506                 x = 0;
 507         }
 508
 509         if (x_end > width)
 510         {
 511                 if (x > width) return;
 512                 x_end = width-1;
 513         }
 514
 515         // TODO: Avoid extra inner conditionals
 516         do
 517         {
 518                 if (x >= 0 && x < width && y >= 0 && y < height)
 519                 {
 520                         int64_t index = (transpose ? (y + x*target.w)*4 : (x + y*target.w)*4);
 521                         target.pixels[index+0] = colour.r;
 522                         target.pixels[index+1] = colour.g;
 523                         target.pixels[index+2] = colour.b;
 524                         target.pixels[index+3] = colour.a;
 525                 }
 526                 if (p < 0)
 527                         p += two_dy;
 528                 else
 529                 {
 530                         if (neg_m) --y; else ++y;
 531                         p += two_dxdy;
 532                 }
 533         } while (++x <= x_end);
 534 }
 535
 536
 537 void ObjectRenderer::FloodFillOnCPU(int64_t x, int64_t y, const PixelBounds & bounds, const CPURenderTarget & target, const Colour & fill, const Colour & stroke)
 538 {
 539         // HACK to prevent overflooding (when the fill points for a path round to the pixel outside the boundary)
 540         // (I totally just made that term up...)
 541         Colour c = GetColour(target, x+1, y);
 542         if (c == fill || c == stroke)
 543                 return;
 544         c = GetColour(target, x-1, y);
 545         if (c == fill || c == stroke)
 546                 return;
 547         c = GetColour(target, x, y+1);
 548         if (c == fill || c == stroke)
 549                 return;
 550         c = GetColour(target, x, y-1);
 551         if (c == fill || c == stroke)
 552                 return;
 553
 554         // The hack works but now we get underflooding, or, "droughts".
 555
 556
 557         queue<PixelPoint > traverse;
 558         traverse.push(PixelPoint(x,y));
 559         // now with 100% less stack overflows!
 560         while (traverse.size() > 0)
 561         {
 562                 PixelPoint cur(traverse.front());
 563                 traverse.pop();
 564                 if (cur.first < 0 || cur.first < bounds.x || cur.first >= bounds.x+bounds.w || cur.first >= target.w ||
 565                         cur.second < 0 || cur.second < bounds.y || cur.second >= bounds.y+bounds.h || cur.second >= target.h)
 566                         continue;
 567                 c = GetColour(target, cur.first, cur.second);
 568                 if (c == fill || c == stroke)
 569                         continue;
 570
 571                 SetColour(target, cur.first, cur.second, fill);
 572
 573                 //Debug("c is {%u,%u,%u,%u} fill is {%u,%u,%u,%u}, stroke is {%u,%u,%u,%u}",
 574                 //      c.r,c.g,c.b,c.a, fill.r,fill.g,fill.b,fill.a, stroke.r,stroke.g,stroke.b,stroke.a);
 575
 576                 traverse.push(PixelPoint(cur.first+1, cur.second));
 577                 traverse.push(PixelPoint(cur.first-1, cur.second));
 578                 traverse.push(PixelPoint(cur.first, cur.second-1));
 579                 traverse.push(PixelPoint(cur.first, cur.second+1));
 580         }
 581 }
 582
 583 }