Root/src/surface.cpp

1/***************************************************************************
2 * Copyright (C) 2006 by Massimiliano Torromeo *
3 * massimiliano.torromeo@gmail.com *
4 * *
5 * This program is free software; you can redistribute it and/or modify *
6 * it under the terms of the GNU General Public License as published by *
7 * the Free Software Foundation; either version 2 of the License, or *
8 * (at your option) any later version. *
9 * *
10 * This program is distributed in the hope that it will be useful, *
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of *
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
13 * GNU General Public License for more details. *
14 * *
15 * You should have received a copy of the GNU General Public License *
16 * along with this program; if not, write to the *
17 * Free Software Foundation, Inc., *
18 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
19 ***************************************************************************/
20
21#include "surface.h"
22
23#include "debug.h"
24#include "imageio.h"
25#include "utilities.h"
26
27#include <algorithm>
28#include <cassert>
29#include <iomanip>
30#include <utility>
31
32using namespace std;
33
34
35// RGBAColor:
36
37RGBAColor RGBAColor::fromString(const string &strColor) {
38    return {
39        uint8_t(constrain(strtol(strColor.substr(0, 2).c_str(), nullptr, 16),
40                          0, 255)),
41        uint8_t(constrain(strtol(strColor.substr(2, 2).c_str(), nullptr, 16),
42                          0, 255)),
43        uint8_t(constrain(strtol(strColor.substr(4, 2).c_str(), nullptr, 16),
44                          0, 255)),
45        uint8_t(constrain(strtol(strColor.substr(6, 2).c_str(), nullptr, 16),
46                          0, 255)),
47    };
48}
49
50ostream& operator<<(ostream& os, RGBAColor const& color) {
51    auto oldfill = os.fill('0');
52    auto oldflags = os.setf(ios::hex | ios::right,
53                            ios::basefield | ios::adjustfield);
54    os << setw(2) << uint32_t(color.r)
55       << setw(2) << uint32_t(color.g)
56       << setw(2) << uint32_t(color.b)
57       << setw(2) << uint32_t(color.a);
58    os.fill(oldfill);
59    os.setf(oldflags);
60    return os;
61}
62
63
64// Surface:
65
66Surface::Surface(Surface const& other)
67    : Surface(SDL_ConvertSurface(other.raw, other.raw->format, SDL_SWSURFACE))
68{
69    // Note: A bug in SDL_ConvertSurface() leaves the per-surface alpha
70    // undefined when converting from RGBA to RGBA. This can cause
71    // problems if the surface is later converted to a format without
72    // an alpha channel, such as the display format.
73    raw->format->alpha = other.raw->format->alpha;
74}
75
76void Surface::blit(SDL_Surface *destination, int x, int y, int w, int h, int a) const {
77    if (destination == NULL || a==0) return;
78
79    SDL_Rect src = { 0, 0, static_cast<Uint16>(w), static_cast<Uint16>(h) };
80    SDL_Rect dest;
81    dest.x = x;
82    dest.y = y;
83    if (a>0 && a!=raw->format->alpha)
84        SDL_SetAlpha(raw, SDL_SRCALPHA|SDL_RLEACCEL, a);
85    SDL_BlitSurface(raw, (w==0 || h==0) ? NULL : &src, destination, &dest);
86}
87void Surface::blit(Surface& destination, int x, int y, int w, int h, int a) const {
88    blit(destination.raw, x, y, w, h, a);
89}
90
91void Surface::blitCenter(SDL_Surface *destination, int x, int y, int w, int h, int a) const {
92    int ow = raw->w / 2; if (w != 0) ow = min(ow, w / 2);
93    int oh = raw->h / 2; if (h != 0) oh = min(oh, h / 2);
94    blit(destination, x - ow, y - oh, w, h, a);
95}
96void Surface::blitCenter(Surface& destination, int x, int y, int w, int h, int a) const {
97    blitCenter(destination.raw, x, y, w, h, a);
98}
99
100void Surface::blitRight(SDL_Surface *destination, int x, int y, int w, int h, int a) const {
101    if (!w) w = raw->w;
102    blit(destination, x - min(raw->w, w), y, w, h, a);
103}
104void Surface::blitRight(Surface& destination, int x, int y, int w, int h, int a) const {
105    if (!w) w = raw->w;
106    blitRight(destination.raw, x, y, w, h, a);
107}
108
109void Surface::box(SDL_Rect re, RGBAColor c) {
110    if (c.a == 255) {
111        SDL_FillRect(raw, &re, c.pixelValue(raw->format));
112    } else if (c.a != 0) {
113        fillRectAlpha(re, c);
114    }
115}
116
117void Surface::rectangle(SDL_Rect re, RGBAColor c) {
118    if (re.h >= 1) {
119        // Top.
120        box(SDL_Rect { re.x, re.y, re.w, 1 }, c);
121    }
122    if (re.h >= 2) {
123        Sint16 ey = re.y + re.h - 1;
124        // Bottom.
125        box(SDL_Rect { re.x, ey, re.w, 1 }, c);
126
127        Sint16 ex = re.x + re.w - 1;
128        Sint16 sy = re.y + 1;
129        Uint16 sh = re.h - 2;
130        // Left.
131        if (re.w >= 1) {
132            box(SDL_Rect { re.x, sy, 1, sh }, c);
133        }
134        // Right.
135        if (re.w >= 2) {
136            box(SDL_Rect { ex, sy, 1, sh }, c);
137        }
138    }
139}
140
141void Surface::clearClipRect() {
142    SDL_SetClipRect(raw,NULL);
143}
144
145void Surface::setClipRect(int x, int y, int w, int h) {
146    SDL_Rect rect = {
147        static_cast<Sint16>(x), static_cast<Sint16>(y),
148        static_cast<Uint16>(w), static_cast<Uint16>(h)
149    };
150    setClipRect(rect);
151}
152
153void Surface::setClipRect(SDL_Rect rect) {
154    SDL_SetClipRect(raw,&rect);
155}
156
157void Surface::applyClipRect(SDL_Rect& rect) {
158    SDL_Rect clip;
159    SDL_GetClipRect(raw, &clip);
160
161    // Clip along X-axis.
162    if (rect.x < clip.x) {
163        rect.w = max(rect.x + rect.w - clip.x, 0);
164        rect.x = clip.x;
165    }
166    if (rect.x + rect.w > clip.x + clip.w) {
167        rect.w = max(clip.x + clip.w - rect.x, 0);
168    }
169
170    // Clip along Y-axis.
171    if (rect.y < clip.y) {
172        rect.h = max(rect.y + rect.h - clip.y, 0);
173        rect.y = clip.y;
174    }
175    if (rect.y + rect.h > clip.y + clip.h) {
176        rect.h = max(clip.y + clip.h - rect.y, 0);
177    }
178}
179
180void Surface::blit(Surface& destination, SDL_Rect container, Font::HAlign halign, Font::VAlign valign) const {
181    switch (halign) {
182    case Font::HAlignLeft:
183        break;
184    case Font::HAlignCenter:
185        container.x += container.w / 2 - raw->w / 2;
186        break;
187    case Font::HAlignRight:
188        container.x += container.w-raw->w;
189        break;
190    }
191
192    switch (valign) {
193    case Font::VAlignTop:
194        break;
195    case Font::VAlignMiddle:
196        container.y += container.h / 2 - raw->h / 2;
197        break;
198    case Font::VAlignBottom:
199        container.y += container.h-raw->h;
200        break;
201    }
202
203    blit(destination, container.x, container.y);
204}
205
206static inline uint32_t mult8x4(uint32_t c, uint8_t a) {
207    return ((((c >> 8) & 0x00FF00FF) * a) & 0xFF00FF00)
208         | ((((c & 0x00FF00FF) * a) & 0xFF00FF00) >> 8);
209}
210
211void Surface::fillRectAlpha(SDL_Rect rect, RGBAColor c) {
212    applyClipRect(rect);
213    if (rect.w == 0 || rect.h == 0) {
214        // Entire rectangle is outside clipping area.
215        return;
216    }
217
218    if (SDL_MUSTLOCK(raw)) {
219        if (SDL_LockSurface(raw) < 0) {
220            return;
221        }
222    }
223
224    SDL_PixelFormat *format = raw->format;
225    uint32_t color = c.pixelValue(format);
226    uint8_t alpha = c.a;
227
228    uint8_t* edge = static_cast<uint8_t*>(raw->pixels)
229                   + rect.y * raw->pitch
230                   + rect.x * format->BytesPerPixel;
231
232    // Blending: surf' = surf * (1 - alpha) + fill * alpha
233
234    if (format->BytesPerPixel == 2) {
235        uint32_t Rmask = format->Rmask;
236        uint32_t Gmask = format->Gmask;
237        uint32_t Bmask = format->Bmask;
238
239        // Pre-multiply the fill color. We're hardcoding alpha to 1: 15/16bpp
240        // modes are unlikely to have an alpha channel and even if they do,
241        // the written alpha isn't used by gmenu2x.
242        uint16_t f = (((color & Rmask) * alpha >> 8) & Rmask)
243                   | (((color & Gmask) * alpha >> 8) & Gmask)
244                   | (((color & Bmask) * alpha >> 8) & Bmask)
245                   | format->Amask;
246        alpha = 255 - alpha;
247
248        for (auto y = 0; y < rect.h; y++) {
249            for (auto x = 0; x < rect.w; x++) {
250                uint16_t& pixel = reinterpret_cast<uint16_t*>(edge)[x];
251                uint32_t R = ((pixel & Rmask) * alpha >> 8) & Rmask;
252                uint32_t G = ((pixel & Gmask) * alpha >> 8) & Gmask;
253                uint32_t B = ((pixel & Bmask) * alpha >> 8) & Bmask;
254                pixel = uint16_t(R | G | B) + f;
255            }
256            edge += raw->pitch;
257        }
258    } else if (format->BytesPerPixel == 4) {
259        // Assume the pixel format uses 8 bits per component; we don't care
260        // which component is where since they all blend the same.
261        uint32_t f = mult8x4(color, alpha); // pre-multiply the fill color
262        alpha = 255 - alpha;
263
264        for (auto y = 0; y < rect.h; y++) {
265            for (auto x = 0; x < rect.w; x++) {
266                uint32_t& pixel = reinterpret_cast<uint32_t*>(edge)[x];
267                pixel = mult8x4(pixel, alpha) + f;
268            }
269            edge += raw->pitch;
270        }
271    } else {
272        assert(false);
273    }
274
275    if (SDL_MUSTLOCK(raw)) {
276        SDL_UnlockSurface(raw);
277    }
278}
279
280
281// OffscreenSurface:
282
283unique_ptr<OffscreenSurface> OffscreenSurface::emptySurface(
284        int width, int height)
285{
286    SDL_Surface *raw = SDL_CreateRGBSurface(
287            SDL_SWSURFACE, width, height, 32, 0, 0, 0, 0);
288    if (!raw) return unique_ptr<OffscreenSurface>();
289    SDL_FillRect(raw, nullptr, SDL_MapRGB(raw->format, 0, 0, 0));
290    return unique_ptr<OffscreenSurface>(new OffscreenSurface(raw));
291}
292
293unique_ptr<OffscreenSurface> OffscreenSurface::loadImage(
294        string const& img, bool loadAlpha)
295{
296    SDL_Surface *raw = loadPNG(img, loadAlpha);
297    if (!raw) {
298        DEBUG("Couldn't load surface '%s'\n", img.c_str());
299        return unique_ptr<OffscreenSurface>();
300    }
301
302    return unique_ptr<OffscreenSurface>(new OffscreenSurface(raw));
303}
304
305OffscreenSurface::OffscreenSurface(OffscreenSurface&& other)
306    : Surface(other.raw)
307{
308    other.raw = nullptr;
309}
310
311OffscreenSurface::~OffscreenSurface()
312{
313    SDL_FreeSurface(raw);
314}
315
316OffscreenSurface& OffscreenSurface::operator=(OffscreenSurface other)
317{
318    swap(other);
319    return *this;
320}
321
322void OffscreenSurface::swap(OffscreenSurface& other)
323{
324    std::swap(raw, other.raw);
325}
326
327void OffscreenSurface::convertToDisplayFormat() {
328    SDL_Surface *newSurface = SDL_DisplayFormat(raw);
329    if (newSurface) {
330        SDL_FreeSurface(raw);
331        raw = newSurface;
332    }
333}
334
335
336// OutputSurface:
337
338unique_ptr<OutputSurface> OutputSurface::open(
339        int width, int height, int bitsPerPixel)
340{
341    SDL_ShowCursor(SDL_DISABLE);
342    SDL_Surface *raw = SDL_SetVideoMode(
343        width, height, bitsPerPixel, SDL_HWSURFACE | SDL_DOUBLEBUF);
344    return unique_ptr<OutputSurface>(raw ? new OutputSurface(raw) : nullptr);
345}
346
347void OutputSurface::flip() {
348    SDL_Flip(raw);
349}
350

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