Lantern. A portable Light Source. Demo in 'data/levels/test/magicblocks.stl'
[supertux.git] / src / video / drawing_context.cpp
1 //  $Id$
2 //
3 //  SuperTux
4 //  Copyright (C) 2006 Matthias Braun <matze@braunis.de>
5 //
6 //  This program is free software; you can redistribute it and/or
7 //  modify it under the terms of the GNU General Public License
8 //  as published by the Free Software Foundation; either version 2
9 //  of the License, or (at your option) any later version.
10 //
11 //  This program is distributed in the hope that it will be useful,
12 //  but WITHOUT ANY WARRANTY; without even the implied warranty of
13 //  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 //  GNU General Public License for more details.
15 //
16 //  You should have received a copy of the GNU General Public License
17 //  along with this program; if not, write to the Free Software
18 //  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
19
20 #include <config.h>
21
22 #include <algorithm>
23 #include <cassert>
24 #include <iostream>
25 #include <SDL_image.h>
26 #include <GL/gl.h>
27
28 #include "drawing_context.hpp"
29 #include "surface.hpp"
30 #include "font.hpp"
31 #include "main.hpp"
32 #include "gameconfig.hpp"
33 #include "glutil.hpp"
34 #include "texture.hpp"
35 #include "texture_manager.hpp"
36 #define LIGHTMAP_DIV 4
37
38 static inline int next_po2(int val)
39 {
40   int result = 1;
41   while(result < val)
42     result *= 2;
43
44   return result;
45 }
46
47 DrawingContext::DrawingContext()
48   : ambient_color( 1.0f, 1.0f, 1.0f, 1.0f )
49 {
50   screen = SDL_GetVideoSurface();
51
52   lightmap_width = screen->w / LIGHTMAP_DIV;
53   lightmap_height = screen->h / LIGHTMAP_DIV;
54   unsigned int width = next_po2(lightmap_width);
55   unsigned int height = next_po2(lightmap_height);
56
57   lightmap = new Texture(width, height, GL_RGB);
58
59   lightmap_uv_right = static_cast<float>(lightmap_width) / static_cast<float>(width);
60   lightmap_uv_bottom = static_cast<float>(lightmap_height) / static_cast<float>(height);
61   texture_manager->register_texture(lightmap);
62
63   requests = &drawing_requests;
64 }
65
66 DrawingContext::~DrawingContext()
67 {
68   texture_manager->remove_texture(lightmap);
69   delete lightmap;
70 }
71
72 void
73 DrawingContext::draw_surface(const Surface* surface, const Vector& position,
74                              float angle, const Color& color, const Blend& blend,
75                              int layer)
76 {
77   assert(surface != 0);
78
79   DrawingRequest request;
80
81   request.type = SURFACE;
82   request.pos = transform.apply(position);
83
84   if(request.pos.x >= SCREEN_WIDTH || request.pos.y >= SCREEN_HEIGHT
85       || request.pos.x + surface->get_width() < 0
86       || request.pos.y + surface->get_height() < 0)
87     return;
88
89   request.layer = layer;
90   request.drawing_effect = transform.drawing_effect;
91   request.alpha = transform.alpha;
92   request.angle = angle;
93   request.color = color;
94   request.blend = blend;
95
96   request.request_data = const_cast<Surface*> (surface);
97
98   requests->push_back(request);
99 }
100
101 void
102 DrawingContext::draw_surface(const Surface* surface, const Vector& position,
103     int layer)
104 {
105   draw_surface(surface, position, 0.0f, Color(1.0f, 1.0f, 1.0f), Blend(), layer);
106 }
107
108 void
109 DrawingContext::draw_surface_part(const Surface* surface, const Vector& source,
110     const Vector& size, const Vector& dest, int layer)
111 {
112   assert(surface != 0);
113
114   DrawingRequest request;
115
116   request.type = SURFACE_PART;
117   request.pos = transform.apply(dest);
118   request.layer = layer;
119   request.drawing_effect = transform.drawing_effect;
120   request.alpha = transform.alpha;
121
122   SurfacePartRequest* surfacepartrequest = new SurfacePartRequest();
123   surfacepartrequest->size = size;
124   surfacepartrequest->source = source;
125   surfacepartrequest->surface = surface;
126
127   // clip on screen borders
128   if(request.pos.x < 0) {
129     surfacepartrequest->size.x += request.pos.x;
130     if(surfacepartrequest->size.x <= 0)
131       return;
132     surfacepartrequest->source.x -= request.pos.x;
133     request.pos.x = 0;
134   }
135   if(request.pos.y < 0) {
136     surfacepartrequest->size.y += request.pos.y;
137     if(surfacepartrequest->size.y <= 0)
138       return;
139     surfacepartrequest->source.y -= request.pos.y;
140     request.pos.y = 0;
141   }
142   request.request_data = surfacepartrequest;
143
144   requests->push_back(request);
145 }
146
147 void
148 DrawingContext::draw_text(const Font* font, const std::string& text,
149     const Vector& position, FontAlignment alignment, int layer)
150 {
151   DrawingRequest request;
152
153   request.type = TEXT;
154   request.pos = transform.apply(position);
155   request.layer = layer;
156   request.drawing_effect = transform.drawing_effect;
157   request.alpha = transform.alpha;
158
159   TextRequest* textrequest = new TextRequest;
160   textrequest->font = font;
161   textrequest->text = text;
162   textrequest->alignment = alignment;
163   request.request_data = textrequest;
164
165   requests->push_back(request);
166 }
167
168 void
169 DrawingContext::draw_center_text(const Font* font, const std::string& text,
170     const Vector& position, int layer)
171 {
172   draw_text(font, text, Vector(position.x + SCREEN_WIDTH/2, position.y),
173       CENTER_ALLIGN, layer);
174 }
175
176 void
177 DrawingContext::draw_gradient(const Color& top, const Color& bottom, int layer)
178 {
179   DrawingRequest request;
180
181   request.type = GRADIENT;
182   request.pos = Vector(0,0);
183   request.layer = layer;
184
185   request.drawing_effect = transform.drawing_effect;
186   request.alpha = transform.alpha;
187
188   GradientRequest* gradientrequest = new GradientRequest;
189   gradientrequest->top = top;
190   gradientrequest->bottom = bottom;
191   request.request_data = gradientrequest;
192
193   requests->push_back(request);
194 }
195
196 void
197 DrawingContext::draw_filled_rect(const Vector& topleft, const Vector& size,
198                                  const Color& color, int layer)
199 {
200   DrawingRequest request;
201
202   request.type = FILLRECT;
203   request.pos = transform.apply(topleft);
204   request.layer = layer;
205
206   request.drawing_effect = transform.drawing_effect;
207   request.alpha = transform.alpha;
208
209   FillRectRequest* fillrectrequest = new FillRectRequest;
210   fillrectrequest->size = size;
211   fillrectrequest->color = color;
212   fillrectrequest->color.alpha = color.alpha * transform.alpha;
213   request.request_data = fillrectrequest;
214
215   requests->push_back(request);
216 }
217
218 void
219 DrawingContext::draw_filled_rect(const Rect& rect, const Color& color,
220                                  int layer)
221 {
222   DrawingRequest request;
223
224   request.type = FILLRECT;
225   request.pos = transform.apply(rect.p1);
226   request.layer = layer;
227
228   request.drawing_effect = transform.drawing_effect;
229   request.alpha = transform.alpha;
230
231   FillRectRequest* fillrectrequest = new FillRectRequest;
232   fillrectrequest->size = Vector(rect.get_width(), rect.get_height());
233   fillrectrequest->color = color;
234   fillrectrequest->color.alpha = color.alpha * transform.alpha;
235   request.request_data = fillrectrequest;
236
237   requests->push_back(request);
238 }
239
240 void
241 DrawingContext::get_light(const Vector& position, Color* color)
242 {
243   if( ambient_color.red == 1.0f && ambient_color.green == 1.0f
244       && ambient_color.blue  == 1.0f ) {
245     *color = Color( 1.0f, 1.0f, 1.0f);
246     return;
247   }
248   DrawingRequest request;
249   request.type = GETLIGHT;
250   request.pos = transform.apply(position);
251   request.layer = LAYER_GUI; //make sure all get_light requests are handled last.
252
253   GetLightRequest* getlightrequest = new GetLightRequest;
254   getlightrequest->color_ptr = color;
255   request.request_data = getlightrequest;
256   lightmap_requests.push_back(request);
257 }
258
259 void
260 DrawingContext::get_light(DrawingRequest& request)
261 {
262   GetLightRequest* getlightrequest = (GetLightRequest*) request.request_data;
263
264   float pixels[3];
265   for( int i = 0; i<3; i++)
266     pixels[i] = 0.0f; //set to black
267
268   //TODO: hacky. Make coordinate conversion more generic
269   glReadPixels((GLint) request.pos.x / 4, 600-(GLint)request.pos.y / 4, 1, 1, GL_RGB, GL_FLOAT, pixels);
270   *(getlightrequest->color_ptr) = Color( pixels[0], pixels[1], pixels[2]);
271   //printf("get_light %f/%f r%f g%f b%f\n", request.pos.x, request.pos.y, pixels[0], pixels[1], pixels[2]);
272
273   delete getlightrequest;
274 }
275
276 void
277 DrawingContext::draw_surface_part(DrawingRequest& request)
278 {
279   SurfacePartRequest* surfacepartrequest
280     = (SurfacePartRequest*) request.request_data;
281
282   surfacepartrequest->surface->draw_part(
283       surfacepartrequest->source.x, surfacepartrequest->source.y,
284       request.pos.x, request.pos.y,
285       surfacepartrequest->size.x, surfacepartrequest->size.y,
286       request.alpha, request.drawing_effect);
287
288   delete surfacepartrequest;
289 }
290
291 void
292 DrawingContext::draw_gradient(DrawingRequest& request)
293 {
294   GradientRequest* gradientrequest = (GradientRequest*) request.request_data;
295   const Color& top = gradientrequest->top;
296   const Color& bottom = gradientrequest->bottom;
297
298   glDisable(GL_TEXTURE_2D);
299   glBegin(GL_QUADS);
300   glColor4f(top.red, top.green, top.blue, top.alpha);
301   glVertex2f(0, 0);
302   glVertex2f(SCREEN_WIDTH, 0);
303   glColor4f(bottom.red, bottom.green, bottom.blue, bottom.alpha);
304   glVertex2f(SCREEN_WIDTH, SCREEN_HEIGHT);
305   glVertex2f(0, SCREEN_HEIGHT);
306   glEnd();
307   glEnable(GL_TEXTURE_2D);
308
309   delete gradientrequest;
310 }
311
312 void
313 DrawingContext::draw_text(DrawingRequest& request)
314 {
315   TextRequest* textrequest = (TextRequest*) request.request_data;
316
317   textrequest->font->draw(textrequest->text, request.pos,
318       textrequest->alignment, request.drawing_effect, request.alpha);
319
320   delete textrequest;
321 }
322
323 void
324 DrawingContext::draw_filled_rect(DrawingRequest& request)
325 {
326   FillRectRequest* fillrectrequest = (FillRectRequest*) request.request_data;
327
328   float x = request.pos.x;
329   float y = request.pos.y;
330   float w = fillrectrequest->size.x;
331   float h = fillrectrequest->size.y;
332
333   glDisable(GL_TEXTURE_2D);
334   glColor4f(fillrectrequest->color.red, fillrectrequest->color.green,
335             fillrectrequest->color.blue, fillrectrequest->color.alpha);
336
337   glBegin(GL_QUADS);
338   glVertex2f(x, y);
339   glVertex2f(x+w, y);
340   glVertex2f(x+w, y+h);
341   glVertex2f(x, y+h);
342   glEnd();
343   glEnable(GL_TEXTURE_2D);
344
345   delete fillrectrequest;
346 }
347
348 void
349 DrawingContext::draw_lightmap(DrawingRequest& request)
350 {
351   const Texture* texture = reinterpret_cast<Texture*> (request.request_data);
352
353   // multiple the lightmap with the framebuffer
354   glBlendFunc(GL_DST_COLOR, GL_ZERO);
355
356   glBindTexture(GL_TEXTURE_2D, texture->get_handle());
357   glBegin(GL_QUADS);
358
359   glTexCoord2f(0, lightmap_uv_bottom);
360   glVertex2f(0, 0);
361
362   glTexCoord2f(lightmap_uv_right, lightmap_uv_bottom);
363   glVertex2f(SCREEN_WIDTH, 0);
364
365   glTexCoord2f(lightmap_uv_right, 0);
366   glVertex2f(SCREEN_WIDTH, SCREEN_HEIGHT);
367
368   glTexCoord2f(0, 0);
369   glVertex2f(0, SCREEN_HEIGHT);
370
371   glEnd();
372
373   glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
374 }
375
376 void
377 DrawingContext::do_drawing()
378 {
379 #ifdef DEBUG
380   assert(transformstack.empty());
381   assert(target_stack.empty());
382 #endif
383   transformstack.clear();
384   target_stack.clear();
385
386   //Use Lightmap if ambient color is not white.
387   bool use_lightmap = ( ambient_color.red != 1.0f   || ambient_color.green != 1.0f ||
388                         ambient_color.blue  != 1.0f );
389
390   // PART1: create lightmap
391   if(use_lightmap) {
392     glViewport(0, screen->h - lightmap_height, lightmap_width, lightmap_height);
393     glMatrixMode(GL_PROJECTION);
394     glLoadIdentity();
395     glOrtho(0, SCREEN_WIDTH, SCREEN_HEIGHT, 0, -1.0, 1.0);
396     glMatrixMode(GL_MODELVIEW);
397     glLoadIdentity();
398
399     glClearColor( ambient_color.red, ambient_color.green, ambient_color.blue, 1 );
400     glClear(GL_COLOR_BUFFER_BIT);
401     handle_drawing_requests(lightmap_requests);
402     lightmap_requests.clear();
403
404     glDisable(GL_BLEND);
405     glBindTexture(GL_TEXTURE_2D, lightmap->get_handle());
406     glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, screen->h - lightmap_height, lightmap_width, lightmap_height);
407
408     glViewport(0, 0, screen->w, screen->h);
409     glMatrixMode(GL_PROJECTION);
410     glLoadIdentity();
411     glOrtho(0, SCREEN_WIDTH, SCREEN_HEIGHT, 0, -1.0, 1.0);
412     glMatrixMode(GL_MODELVIEW);
413     glLoadIdentity();
414     glEnable(GL_BLEND);
415
416     // add a lightmap drawing request into the queue
417     DrawingRequest request;
418     request.type = LIGHTMAPREQUEST;
419     request.layer = LAYER_HUD - 1;
420     request.request_data = lightmap;
421     requests->push_back(request);
422   }
423
424   //glClear(GL_COLOR_BUFFER_BIT);
425   handle_drawing_requests(drawing_requests);
426   drawing_requests.clear();
427   assert_gl("drawing");
428
429   SDL_GL_SwapBuffers();
430 }
431
432 void
433 DrawingContext::handle_drawing_requests(DrawingRequests& requests)
434 {
435   std::stable_sort(requests.begin(), requests.end());
436
437   for(DrawingRequests::iterator i = requests.begin();
438       i != requests.end(); ++i) {
439     switch(i->type) {
440       case SURFACE:
441       {
442         const Surface* surface = (const Surface*) i->request_data;
443         surface->draw(i->pos.x, i->pos.y, i->alpha, i->angle, i->color, i->blend, i->drawing_effect);
444         break;
445       }
446       case SURFACE_PART:
447         draw_surface_part(*i);
448         break;
449       case GRADIENT:
450         draw_gradient(*i);
451         break;
452       case TEXT:
453         draw_text(*i);
454         break;
455       case FILLRECT:
456         draw_filled_rect(*i);
457         break;
458       case LIGHTMAPREQUEST:
459         draw_lightmap(*i);
460         break;
461       case GETLIGHT:
462         get_light(*i);
463         break;
464     }
465   }
466 }
467
468 void
469 DrawingContext::push_transform()
470 {
471   transformstack.push_back(transform);
472 }
473
474 void
475 DrawingContext::pop_transform()
476 {
477   assert(!transformstack.empty());
478
479   transform = transformstack.back();
480   transformstack.pop_back();
481 }
482
483 void
484 DrawingContext::set_drawing_effect(DrawingEffect effect)
485 {
486   transform.drawing_effect = effect;
487 }
488
489 DrawingEffect
490 DrawingContext::get_drawing_effect() const
491 {
492   return transform.drawing_effect;
493 }
494
495 void
496 DrawingContext::set_alpha(float alpha)
497 {
498   transform.alpha = alpha;
499 }
500
501 float
502 DrawingContext::get_alpha() const
503 {
504   return transform.alpha;
505 }
506
507 void
508 DrawingContext::push_target()
509 {
510   target_stack.push_back(target);
511 }
512
513 void
514 DrawingContext::pop_target()
515 {
516   set_target(target_stack.back());
517   target_stack.pop_back();
518 }
519
520 void
521 DrawingContext::set_target(Target target)
522 {
523   this->target = target;
524   if(target == LIGHTMAP)
525     requests = &lightmap_requests;
526   else
527     requests = &drawing_requests;
528 }
529
530 void
531 DrawingContext::set_ambient_color( Color new_color )
532 {
533   ambient_color = new_color;
534 }