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         if (vert_glsl_file != NULL && frag_glsl_file != NULL && geom_glsl_file != NULL)
  28         {
  29                 m_shader_program.InitialiseShaders(vert_glsl_file, frag_glsl_file, geom_glsl_file);
  30                 m_shader_program.Use();
  31                 glUniform4f(m_shader_program.GetUniformLocation("colour"), 0,0,0,1); //TODO: Allow different colours
  32         }
  33 }
  34
  35 /**
  36  * Render using GPU
  37  */
  38 void ObjectRenderer::RenderUsingGPU(unsigned first_obj_id, unsigned last_obj_id)
  39 {
  40         // If we don't have anything to render, return.
  41         if (first_obj_id == last_obj_id) return;
  42         // If there are no objects of this type, return.
  43         if (m_indexes.empty()) return;
  44         unsigned first_index = 0;
  45         while (m_indexes.size() > first_index && m_indexes[first_index] < first_obj_id) first_index ++;
  46         unsigned last_index = first_index;
  47         while (m_indexes.size() > last_index && m_indexes[last_index] < last_obj_id) last_index ++;
  48
  49         m_shader_program.Use();
  50         m_ibo.Bind();
  51         glDrawElements(GL_LINES, (last_index-first_index)*2, GL_UNSIGNED_INT, (GLvoid*)(2*first_index*sizeof(uint32_t)));
  52 }
  53
  54
  55 /**
  56  * Default implementation for rendering using CPU
  57  */
  58 void ObjectRenderer::RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id)
  59 {
  60         Error("Cannot render objects of type %d on CPU", m_type);
  61         //TODO: Render a rect or something instead?
  62 }
  63
  64 /**
  65  * Prepare index buffers for both CPU and GPU rendering to receive indexes (but don't add any yet!)
  66  */
  67 void ObjectRenderer::PrepareBuffers(unsigned max_objects)
  68 {
  69         if (m_buffer_builder != NULL) // We already have a BufferBuilder
  70         {
  71                 Fatal("Has been called before, without FinaliseBuffers being called since!");
  72         }
  73         // Empty and reserve the indexes vector (for CPU rendering)
  74         m_indexes.clear();
  75         m_indexes.reserve(max_objects); //TODO: Can probably make this smaller? Or leave it out? Do we care?
  76
  77         // Initialise and resize the ibo (for GPU rendering)
  78         m_ibo.Invalidate();
  79         m_ibo.SetUsage(GraphicsBuffer::BufferUsageStaticDraw);
  80         m_ibo.SetType(GraphicsBuffer::BufferTypeIndex);
  81         m_ibo.Resize(max_objects * 2 * sizeof(uint32_t));
  82         // BufferBuilder is used to construct the ibo
  83         m_buffer_builder = new BufferBuilder<uint32_t>(m_ibo.Map(false, true, true), m_ibo.GetSize()); // new matches delete in ObjectRenderer::FinaliseBuffers
  84
  85 }
  86
  87 /**
  88  * Add object index to the buffers for CPU and GPU rendering
  89  */
  90 void ObjectRenderer::AddObjectToBuffers(unsigned index)
  91 {
  92         if (m_buffer_builder == NULL) // No BufferBuilder!
  93         {
  94                 Fatal("Called without calling PrepareBuffers");
  95         }
  96         m_buffer_builder->Add(2*index); // ibo for GPU rendering
  97         m_buffer_builder->Add(2*index+1);
  98         m_indexes.push_back(index); // std::vector of indices for CPU rendering
  99 }
 100
 101 /**
 102  * Finalise the index buffers for CPU and GPU rendering
 103  */
 104 void ObjectRenderer::FinaliseBuffers()
 105 {
 106         if (m_buffer_builder == NULL) // No BufferBuilder!
 107         {
 108                 Fatal("Called without calling PrepareBuffers");
 109         }
 110         // For GPU rendering, UnMap the ibo
 111         m_ibo.UnMap();
 112         // ... and delete the BufferBuilder used to create it
 113         delete m_buffer_builder; // delete matches new in ObjectRenderer::PrepareBuffers
 114         m_buffer_builder = NULL;
 115
 116         // Nothing is necessary for CPU rendering
 117 }
 118
 119
 120 /**
 121  * Rectangle (filled)
 122  */
 123 void RectFilledRenderer::RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id)
 124 {
 125         for (unsigned i = 0; i < m_indexes.size(); ++i)
 126         {
 127                 if (m_indexes[i] < first_obj_id) continue;
 128                 if (m_indexes[i] >= last_obj_id) continue;
 129                 PixelBounds bounds(CPURenderBounds(objects.bounds[m_indexes[i]], view, target));
 130                 FloodFillOnCPU(bounds.x+1, bounds.y+1, bounds, target, Colour(0,0,0,1));
 131                 /*
 132                 for (int64_t x = max((int64_t)0, bounds.x); x <= min(bounds.x+bounds.w, target.w-1); ++x)
 133                 {
 134                         for (int64_t y = max((int64_t)0, bounds.y); y <= min(bounds.y+bounds.h, target.h-1); ++y)
 135                         {
 136                                 int index = (x+target.w*y)*4;
 137                                 target.pixels[index+0] = 0;
 138                                 target.pixels[index+1] = 0;
 139                                 target.pixels[index+2] = 0;
 140                                 target.pixels[index+3] = 255;
 141                         }
 142                 }
 143                 */
 144         }
 145 }
 146
 147 /**
 148  * Rectangle (outine)
 149  */
 150 void RectOutlineRenderer::RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id)
 151 {
 152         //Debug("Render %u outlined rectangles on CPU", m_indexes.size());
 153         for (unsigned i = 0; i < m_indexes.size(); ++i)
 154         {
 155                 if (m_indexes[i] < first_obj_id) continue;
 156                 if (m_indexes[i] >= last_obj_id) continue;
 157                 PixelBounds bounds(CPURenderBounds(objects.bounds[m_indexes[i]], view, target));
 158
 159                 // Using bresenham's lines now mainly because I want to see if they work
 160                 // top
 161                 ObjectRenderer::RenderLineOnCPU(bounds.x, bounds.y, bounds.x+bounds.w, bounds.y, target);
 162                 // bottom
 163                 ObjectRenderer::RenderLineOnCPU(bounds.x, bounds.y+bounds.h, bounds.x+bounds.w, bounds.y+bounds.h, target);
 164                 // left
 165                 ObjectRenderer::RenderLineOnCPU(bounds.x, bounds.y, bounds.x, bounds.y+bounds.h, target);
 166                 // right
 167                 ObjectRenderer::RenderLineOnCPU(bounds.x+bounds.w, bounds.y, bounds.x+bounds.w, bounds.y+bounds.h, target);
 168
 169                 // Diagonal for testing (from bottom left to top right)
 170                 //ObjectRenderer::RenderLineOnCPU(bounds.x,bounds.y+bounds.h, bounds.x+bounds.w, bounds.y,target, C_BLUE);
 171                 //ObjectRenderer::RenderLineOnCPU(bounds.x+bounds.w, bounds.y+bounds.h, bounds.x, bounds.y, target,C_GREEN);
 172         }
 173 }
 174
 175 /**
 176  * Circle (filled)
 177  */
 178 void CircleFilledRenderer::RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id)
 179 {
 180         for (unsigned i = 0; i < m_indexes.size(); ++i)
 181         {
 182                 if (m_indexes[i] < first_obj_id) continue;
 183                 if (m_indexes[i] >= last_obj_id) continue;
 184                 PixelBounds bounds(CPURenderBounds(objects.bounds[m_indexes[i]], view, target));
 185                 int64_t centre_x = bounds.x + bounds.w / 2;
 186                 int64_t centre_y = bounds.y + bounds.h / 2;
 187
 188                 //Debug("Centre is %d, %d", centre_x, centre_y);
 189                 //Debug("Bounds are %d,%d,%d,%d", bounds.x, bounds.y, bounds.w, bounds.h);
 190                 //Debug("Windos is %d,%d", target.w, target.h);
 191                 for (int64_t x = max((int64_t)0, bounds.x); x <= min(bounds.x+bounds.w, target.w-1); ++x)
 192                 {
 193                         for (int64_t y = max((int64_t)0, bounds.y); y <= min(bounds.y + bounds.h, target.h-1); ++y)
 194                         {
 195                                 Real dx(2); dx *= Real(x - centre_x)/Real(bounds.w);
 196                                 Real dy(2); dy *= Real(y - centre_y)/Real(bounds.h);
 197                                 int64_t index = (x+target.w*y)*4;
 198
 199                                 if (dx*dx + dy*dy <= Real(1))
 200                                 {
 201                                         target.pixels[index+0] = 0;
 202                                         target.pixels[index+1] = 0;
 203                                         target.pixels[index+2] = 0;
 204                                         target.pixels[index+3] = 255;
 205                                 }
 206                         }
 207                 }
 208         }
 209 }
 210
 211 Rect ObjectRenderer::CPURenderBounds(const Rect & bounds, const View & view, const CPURenderTarget & target)
 212 {
 213         Rect result = view.TransformToViewCoords(bounds);
 214         result.x *= Real(target.w);
 215         result.y *= Real(target.h);
 216         result.w *= Real(target.w);
 217         result.h *= Real(target.h);
 218         return result;
 219 }
 220
 221 ObjectRenderer::PixelPoint ObjectRenderer::CPUPointLocation(const Vec2 & point, const View & view, const CPURenderTarget & target)
 222 {
 223         // hack...
 224         Rect result = view.TransformToViewCoords(Rect(point.x, point.y,1,1));
 225         int64_t x = Int64(result.x)*target.w;
 226         int64_t y = Int64(result.y)*target.h;
 227         return PixelPoint(x,y);
 228 }
 229
 230
 231 void BezierRenderer::RenderBezierOnCPU(const Bezier & relative, const Rect & bounds, const View & view, const CPURenderTarget & target, const Colour & c)
 232 {
 233         //const Rect & bounds = objects.bounds[i];
 234         PixelBounds pix_bounds(CPURenderBounds(bounds,view,target));
 235         //Bezier control(objects.beziers[objects.data_indices[i]].ToAbsolute(bounds),CPURenderBounds(Rect(0,0,1,1), view, target));
 236         Bezier control(relative.ToAbsolute(bounds), Rect(0,0,target.w, target.h));
 237
 238         if (view.ShowingBezierBounds())
 239         {
 240                 ObjectRenderer::RenderLineOnCPU(pix_bounds.x, pix_bounds.y, pix_bounds.x+pix_bounds.w, pix_bounds.y, target, Colour(255,0,0,0));
 241                 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));
 242                 ObjectRenderer::RenderLineOnCPU(pix_bounds.x, pix_bounds.y, pix_bounds.x, pix_bounds.y+pix_bounds.h, target, Colour(255,0,0,0));
 243                 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));
 244         }
 245
 246         unsigned blen = pix_bounds.w;//min(max(2U, (unsigned)Int64(Real(target.w)/view.GetBounds().w)),
 247                         //min((unsigned)(pix_bounds.w+pix_bounds.h)/4 + 1, 100U));
 248
 249                 // DeCasteljau Divide the Bezier
 250         #ifdef BEZIER_CPU_DECASTELJAU
 251         queue<Bezier> divisions;
 252         divisions.push(control);
 253         while(divisions.size() < blen)
 254         {
 255                 Bezier & current = divisions.front();
 256                 //if (current.GetType() == Bezier::LINE)
 257                 //{
 258                 //      --blen;
 259                 //      continue;
 260                 //}
 261                 divisions.push(current.DeCasteljauSubdivideRight(Real(1)/Real(2)));
 262                 divisions.push(current.DeCasteljauSubdivideLeft(Real(1)/Real(2)));
 263                 divisions.pop();
 264         }
 265         while (divisions.size() > 0)
 266         {
 267                 Bezier & current = divisions.front();
 268                 RenderLineOnCPU(Int64(current.x0), Int64(current.y0), Int64(current.x3), Int64(current.y3), target, c);
 269                 divisions.pop();
 270         }
 271         #else
 272                 Real invblen(1); invblen /= Real(blen);
 273
 274                 Real t(invblen);
 275                 Vec2 v0;
 276                 Vec2 v1;
 277                 control.Evaluate(v0.x, v0.y, 0);
 278                 for (int64_t j = 1; j <= blen; ++j)
 279                 {
 280                         control.Evaluate(v1.x, v1.y, t);
 281                         RenderLineOnCPU(v0.x, v0.y, v1.x, v1.y, target);
 282                         t += invblen;
 283                         v0 = v1;
 284                 }
 285         #endif //BEZIER_CPU_DECASTELJAU
 286 }
 287
 288 /**
 289  * Bezier curve
 290  * Not sure how to apply De'Casteljau, will just use a bunch of Bresnham lines for now.
 291  */
 292 void BezierRenderer::RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id)
 293 {
 294         #ifdef TRANSFORM_BEZIERS_TO_PATH
 295                 return;
 296         #endif
 297         if (view.PerformingShading())
 298                 return;
 299
 300         //Warn("Rendering Beziers on CPU. Things may explode.");
 301         for (unsigned i = 0; i < m_indexes.size(); ++i)
 302         {
 303                 if (m_indexes[i] < first_obj_id) continue;
 304                 if (m_indexes[i] >= last_obj_id) continue;
 305                 Colour c(0,0,0,255);
 306                 if (view.ShowingBezierType())
 307                 {
 308                         switch (objects.beziers[objects.data_indices[m_indexes[i]]].GetType())
 309                         {
 310                                 case Bezier::LINE:
 311                                         break;
 312                                 case Bezier::QUADRATIC:
 313                                         c.b = 255;
 314                                         break;
 315                                 case Bezier::SERPENTINE:
 316                                         c.r = 255;
 317                                         break;
 318                                 case Bezier::CUSP:
 319                                         c.g = 255;
 320                                         break;
 321                                 case Bezier::LOOP:
 322                                         c.r = 128;
 323                                         c.b = 128;
 324                                         break;
 325                                 default:
 326                                         c.r = 128;
 327                                         c.g = 128;
 328                                         break;
 329                         }
 330                 }
 331                 Rect & bounds = objects.bounds[m_indexes[i]];
 332                 Bezier & bez = objects.beziers[objects.data_indices[m_indexes[i]]];
 333                 RenderBezierOnCPU(bez, bounds, view, target, c);
 334         }
 335 }
 336
 337 void BezierRenderer::PrepareBezierGPUBuffer(Objects & objects)
 338 {
 339         m_bezier_coeffs.SetType(GraphicsBuffer::BufferTypeTexture);
 340         m_bezier_coeffs.SetUsage(GraphicsBuffer::BufferUsageDynamicDraw);
 341         m_bezier_coeffs.Resize(objects.beziers.size()*sizeof(GPUBezierCoeffs));
 342         BufferBuilder<GPUBezierCoeffs> builder(m_bezier_coeffs.Map(false, true, true), m_bezier_coeffs.GetSize());
 343
 344
 345         for (unsigned i = 0; i < objects.beziers.size(); ++i)
 346         {
 347                 const Bezier & bez = objects.beziers[i];
 348                 GPUBezierCoeffs coeffs = {
 349                         Float(bez.x0), Float(bez.y0),
 350                         Float(bez.x1), Float(bez.y1),
 351                         Float(bez.x2), Float(bez.y2),
 352                         Float(bez.x3), Float(bez.y3)
 353                         };
 354                 builder.Add(coeffs);
 355         }
 356
 357         m_bezier_coeffs.UnMap();
 358         glGenTextures(1, &m_bezier_buffer_texture);
 359         glBindTexture(GL_TEXTURE_BUFFER, m_bezier_buffer_texture);
 360         glTexBuffer(GL_TEXTURE_BUFFER, GL_RG32F, m_bezier_coeffs.GetHandle());
 361
 362         m_bezier_ids.SetType(GraphicsBuffer::BufferTypeTexture);
 363         m_bezier_ids.SetUsage(GraphicsBuffer::BufferUsageDynamicDraw);
 364         m_bezier_ids.Upload(objects.data_indices.size() * sizeof(uint32_t), &objects.data_indices[0]);
 365
 366         glGenTextures(1, &m_bezier_id_buffer_texture);
 367         glActiveTexture(GL_TEXTURE1);
 368         glBindTexture(GL_TEXTURE_BUFFER, m_bezier_id_buffer_texture);
 369         glTexBuffer(GL_TEXTURE_BUFFER, GL_R32I, m_bezier_ids.GetHandle());
 370         glActiveTexture(GL_TEXTURE0);
 371 }
 372
 373 void BezierRenderer::RenderUsingGPU(unsigned first_obj_id, unsigned last_obj_id)
 374 {
 375
 376         if (!m_shader_program.Valid())
 377                 Warn("Shader is invalid (objects are of type %d)", m_type);
 378
 379         // If we don't have anything to render, return.
 380         if (first_obj_id == last_obj_id) return;
 381         // If there are no objects of this type, return.
 382         if (m_indexes.empty()) return;
 383
 384         unsigned first_index = 0;
 385         while (m_indexes.size() > first_index && m_indexes[first_index] < first_obj_id) first_index ++;
 386         unsigned last_index = first_index;
 387         while (m_indexes.size() > last_index && m_indexes[last_index] < last_obj_id) last_index ++;
 388
 389         m_shader_program.Use();
 390         glUniform1i(m_shader_program.GetUniformLocation("bezier_buffer_texture"), 0);
 391         glUniform1i(m_shader_program.GetUniformLocation("bezier_id_buffer_texture"), 1);
 392         m_ibo.Bind();
 393         glDrawElements(GL_LINES, (last_index-first_index)*2, GL_UNSIGNED_INT, (GLvoid*)(2*first_index*sizeof(uint32_t)));
 394 }
 395
 396
 397
 398 /**
 399  * Render Path (shading)
 400  */
 401 void PathRenderer::RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id)
 402 {
 403
 404
 405         for (unsigned i = 0; i < m_indexes.size(); ++i)
 406         {
 407                 if (m_indexes[i] < first_obj_id) continue;
 408                 if (m_indexes[i] >= last_obj_id) continue;
 409
 410
 411                 Rect bounds(CPURenderBounds(objects.bounds[m_indexes[i]], view, target));
 412                 PixelBounds pix_bounds(bounds);
 413                 Path & path = objects.paths[objects.data_indices[m_indexes[i]]];
 414
 415                 if (view.ShowingFillPoints())
 416                 {
 417
 418                         PixelPoint start(CPUPointLocation((path.m_top+path.m_left+path.m_right+path.m_bottom)/4, view, target));
 419                         for (unsigned f = 0; f < path.m_fill_points.size(); ++f)
 420                         {
 421                                 PixelPoint end(CPUPointLocation(path.m_fill_points[f], view, target));
 422                                 RenderLineOnCPU(start.first, start.second, end.first, end.second, target, Colour(0,0,255,0));
 423                         }
 424                 }
 425
 426                 #ifndef TRANSFORM_BEZIERS_TO_PATH
 427                 if (!view.PerformingShading())
 428                         continue;
 429                 for (unsigned b = path.m_start; b <= path.m_end; ++b)
 430                 {
 431                         Rect & bbounds = objects.bounds[b];
 432                         Bezier & bez = objects.beziers[objects.data_indices[b]];
 433                         BezierRenderer::RenderBezierOnCPU(bez,bbounds,view,target,path.m_stroke);
 434                 }
 435                 #else
 436                 // Outlines still get drawn if using TRANSFORM_BEZIERS_TO_PATH
 437                 for (unsigned b = path.m_start; b <= path.m_end; ++b)
 438                 {
 439                         Colour stroke = (view.PerformingShading()) ? path.m_stroke : Colour(0,0,0,255);
 440                         // bezier's bounds are relative to this object's bounds, convert back to view bounds
 441                         Rect bbounds = objects.bounds[b];
 442                         bbounds.x *= objects.bounds[m_indexes[i]].w;
 443                         bbounds.x += objects.bounds[m_indexes[i]].x;
 444                         bbounds.y *= objects.bounds[m_indexes[i]].h;
 445                         bbounds.y += objects.bounds[m_indexes[i]].y;
 446                         bbounds.w *= objects.bounds[m_indexes[i]].w;
 447                         bbounds.h *= objects.bounds[m_indexes[i]].h;
 448                         bbounds = view.TransformToViewCoords(bbounds);
 449                         //Debug("Bounds: %s", objects.bounds[m_indexes[i]].Str().c_str());
 450                         //Debug("Relative Bez Bounds: %s", objects.bounds[b].Str().c_str());
 451                         //Debug("Bez Bounds: %s", bbounds.Str().c_str());
 452
 453                         Bezier & bez = objects.beziers[objects.data_indices[b]];
 454
 455                         BezierRenderer::RenderBezierOnCPU(bez,bbounds,view,target, stroke);
 456                 }
 457                 if (!view.PerformingShading())
 458                         continue;
 459                 #endif
 460
 461
 462                 if (pix_bounds.w*pix_bounds.h > 100)
 463                 {
 464                         vector<Vec2> & fill_points = path.FillPoints(objects, view);
 465                         Debug("High resolution; use fill points %u,%u", pix_bounds.w, pix_bounds.h);
 466                         for (unsigned f = 0; f < fill_points.size(); ++f)
 467                         {
 468                                 PixelPoint fill_point(CPUPointLocation(fill_points[f], view, target));
 469
 470                                 FloodFillOnCPU(fill_point.first, fill_point.second, pix_bounds, target, path.m_fill, path.m_stroke);
 471                         }
 472                 }
 473                 else
 474                 {
 475                         Debug("Low resolution; use brute force %u,%u",pix_bounds.w, pix_bounds.h);
 476                         int64_t y_min = max((int64_t)0, pix_bounds.y);
 477                         int64_t y_max = min(pix_bounds.y+pix_bounds.h, target.h);
 478                         int64_t x_min = max((int64_t)0, pix_bounds.x);
 479                         int64_t x_max = min(pix_bounds.x+pix_bounds.w, target.w);
 480                         for (int64_t y = y_min; y < y_max; ++y)
 481                         {
 482                                 for (int64_t x = x_min; x < x_max; ++x)
 483                                 {
 484                                         Rect pb(path.SolveBounds(objects));
 485                                         Vec2 pt(pb.x + (Real(x-pix_bounds.x)/Real(pix_bounds.w))*pb.w,
 486                                                         pb.y + (Real(y-pix_bounds.y)/Real(pix_bounds.h))*pb.h);
 487                                         if (path.PointInside(objects, pt))
 488                                         {
 489                                                 FloodFillOnCPU(x, y, pix_bounds, target, path.m_fill, path.m_stroke);
 490                                         }
 491                                 }
 492                         }
 493                 }
 494         }
 495 }
 496
 497
 498
 499
 500 /**
 501  * For debug, save pixels to bitmap
 502  */
 503 void ObjectRenderer::SaveBMP(const CPURenderTarget & target, const char * filename)
 504 {
 505         SDL_Surface * surf = SDL_CreateRGBSurfaceFrom(target.pixels, target.w, target.h, 8*4, target.w*4,
 506         #if SDL_BYTEORDER == SDL_LIL_ENDIAN
 507                 0x000000ff, 0x0000ff00, 0x00ff0000, 0xff000000
 508         #else
 509                 0xff000000, 0x00ff0000, 0x0000ff00, 0x000000ff
 510         #endif //SDL_BYTEORDER
 511         );
 512         if (surf == NULL)
 513                 Fatal("SDL_CreateRGBSurfaceFrom(pixels...) failed - %s", SDL_GetError());
 514         if (SDL_SaveBMP(surf, filename) != 0)
 515                 Fatal("SDL_SaveBMP failed - %s", SDL_GetError());
 516
 517         // Cleanup
 518         SDL_FreeSurface(surf);
 519 }
 520
 521
 522
 523
 524 /**
 525  * Bresenham's lines
 526  */
 527 void ObjectRenderer::RenderLineOnCPU(int64_t x0, int64_t y0, int64_t x1, int64_t y1, const CPURenderTarget & target, const Colour & colour, bool transpose)
 528 {
 529         int64_t dx = x1 - x0;
 530         int64_t dy = y1 - y0;
 531         bool neg_m = (dy*dx < 0);
 532         dy = abs(dy);
 533         dx = abs(dx);
 534
 535         // If positive slope > 1, just swap x and y
 536         if (dy > dx)
 537         {
 538                 RenderLineOnCPU(y0,x0,y1,x1,target,colour,!transpose);
 539                 return;
 540         }
 541
 542         int64_t two_dy = 2*dy;
 543         int64_t p = two_dy - dx;
 544         int64_t two_dxdy = 2*(dy-dx);
 545         int64_t x; int64_t y; int64_t x_end;
 546         int64_t width = (transpose ? target.h : target.w);
 547         int64_t height = (transpose ? target.w : target.h);
 548
 549         if (x0 > x1)
 550         {
 551                 x = x1;
 552                 y = y1;
 553                 x_end = x0;
 554         }
 555         else
 556         {
 557                 x = x0;
 558                 y = y0;
 559                 x_end = x1;
 560         }
 561
 562         if (x < 0)
 563         {
 564                 if (x_end < 0) return;
 565                 y = (neg_m ? y - (dy*-x)/dx : y + (dy*-x)/dx);
 566                 x = 0;
 567         }
 568
 569         if (x_end > width)
 570         {
 571                 if (x > width) return;
 572                 x_end = width-1;
 573         }
 574
 575         // TODO: Avoid extra inner conditionals
 576         do
 577         {
 578                 if (x >= 0 && x < width && y >= 0 && y < height)
 579                 {
 580                         int64_t index = (transpose ? (y + x*target.w)*4 : (x + y*target.w)*4);
 581                         target.pixels[index+0] = colour.r;
 582                         target.pixels[index+1] = colour.g;
 583                         target.pixels[index+2] = colour.b;
 584                         target.pixels[index+3] = colour.a;
 585                 }
 586                 if (p < 0)
 587                         p += two_dy;
 588                 else
 589                 {
 590                         if (neg_m) --y; else ++y;
 591                         p += two_dxdy;
 592                 }
 593         } while (++x <= x_end);
 594 }
 595
 596
 597 void ObjectRenderer::FloodFillOnCPU(int64_t x, int64_t y, const PixelBounds & bounds, const CPURenderTarget & target, const Colour & fill, const Colour & stroke)
 598 {
 599         // HACK to prevent overflooding (when the fill points for a path round to the pixel outside the boundary)
 600         // (I totally just made that term up...)
 601         Colour c = GetColour(target, x+1, y);
 602         if (c == fill || c == stroke)
 603                 return;
 604         c = GetColour(target, x-1, y);
 605         if (c == fill || c == stroke)
 606                 return;
 607         c = GetColour(target, x, y+1);
 608         if (c == fill || c == stroke)
 609                 return;
 610         c = GetColour(target, x, y-1);
 611         if (c == fill || c == stroke)
 612                 return;
 613
 614         // The hack works but now we get underflooding, or, "droughts".
 615
 616
 617         queue<PixelPoint > traverse;
 618         traverse.push(PixelPoint(x,y));
 619         // now with 100% less stack overflows!
 620         while (traverse.size() > 0)
 621         {
 622                 PixelPoint cur(traverse.front());
 623                 traverse.pop();
 624                 if (cur.first < 0 || cur.first < bounds.x || cur.first >= bounds.x+bounds.w || cur.first >= target.w ||
 625                         cur.second < 0 || cur.second < bounds.y || cur.second >= bounds.y+bounds.h || cur.second >= target.h)
 626                         continue;
 627                 c = GetColour(target, cur.first, cur.second);
 628                 if (c == fill || c == stroke)
 629                         continue;
 630
 631                 SetColour(target, cur.first, cur.second, fill);
 632
 633                 //Debug("c is {%u,%u,%u,%u} fill is {%u,%u,%u,%u}, stroke is {%u,%u,%u,%u}",
 634                 //      c.r,c.g,c.b,c.a, fill.r,fill.g,fill.b,fill.a, stroke.r,stroke.g,stroke.b,stroke.a);
 635
 636                 traverse.push(PixelPoint(cur.first+1, cur.second));
 637                 traverse.push(PixelPoint(cur.first-1, cur.second));
 638                 traverse.push(PixelPoint(cur.first, cur.second-1));
 639                 traverse.push(PixelPoint(cur.first, cur.second+1));
 640         }
 641 }
 642
 643 }