10 /* APPROX. 170 FPS Minimum */
17 static RLEBitmap rleCreate(unsigned int w, unsigned int h);
18 static void rleDestroy(RLEBitmap b);
19 static void rleBlit(unsigned short *dst, int dstW, int dstH, int dstStride,
20 RLEBitmap bitmap, int blitX, int blitY);
21 static void rleBlitScale(unsigned short *dst, int dstW, int dstH, int dstStride,
22 RLEBitmap bitmap, int blitX, int blitY, float scaleX, float scaleY);
23 static void rleBlitScaleInv(unsigned short *dst, int dstW, int dstH, int dstStride,
24 RLEBitmap bitmap, int blitX, int blitY, float scaleX, float scaleY);
25 static RLEBitmap rleEncode(unsigned char *pixels, unsigned int w, unsigned int h);
27 #define BG_FILENAME "data/grise.png"
28 #define GROBJ_01_FILENAME "data/grobj_01.png"
30 #define BB_SIZE 512 /* Let's use a power of 2. Maybe we'll zoom/rotate the effect */
32 /* Every backBuffer scanline is guaranteed to have that many dummy pixels before and after */
33 #define PIXEL_PADDING 32
35 /* Make sure this is less than PIXEL_PADDING*/
36 #define MAX_DISPLACEMENT 16
38 #define MIN_SCROLL PIXEL_PADDING
39 #define MAX_SCROLL (backgroundW - fb_width - MIN_SCROLL)
41 #define FAR_SCROLL_SPEED 15.0f
42 #define NEAR_SCROLL_SPEED 120.0f
44 #define HORIZON_HEIGHT 100
45 #define REFLECTION_HEIGHT (240 - HORIZON_HEIGHT)
47 #define NORMALMAP_SCANLINE 372
49 static int init(void);
50 static void destroy(void);
51 static void start(long trans_time);
52 static void stop(long trans_time);
53 static void draw(void);
55 static void convert32To16(unsigned int *src32, unsigned short *dst16, unsigned int pixelCount);
56 static void processNormal();
57 static void initScrollTables();
58 static void updateScrollTables(float dt);
62 static unsigned short *background = 0;
63 static unsigned int backgroundW = 0;
64 static unsigned int backgroundH = 0;
66 static unsigned int lastFrameTime = 0;
67 static float lastFrameDuration = 0.0f;
69 static short *displacementMap;
71 static unsigned short *backBuffer;
73 static float scrollScaleTable[REFLECTION_HEIGHT];
74 static float scrollTable[REFLECTION_HEIGHT];
75 static int scrollTableRounded[REFLECTION_HEIGHT];
76 static int scrollModTable[REFLECTION_HEIGHT];
77 static float nearScrollAmount = 0.0f;
79 static RLEBitmap grobj;
81 static struct screen scr = {
90 struct screen *grise_screen(void)
98 unsigned char *tmpBitmap;
99 int tmpBitmapW, tmpBitmapH;
101 /* Allocate back buffer */
102 backBuffer = (unsigned short*) calloc(BB_SIZE * BB_SIZE, sizeof(unsigned short));
104 /* grise.png contains the background (horizon), baked reflection and normalmap for displacement */
105 if (!(background = img_load_pixels(BG_FILENAME, &backgroundW, &backgroundH, IMG_FMT_RGBA32))) {
106 fprintf(stderr, "failed to load image " BG_FILENAME "\n");
110 /* Convert to 16bpp */
111 convert32To16((unsigned int*)background, background, backgroundW * NORMALMAP_SCANLINE); /* Normalmap will keep its 32 bit color */
113 /* Load reflected objects */
114 if (!(tmpBitmap = img_load_pixels(GROBJ_01_FILENAME, &tmpBitmapW, &tmpBitmapH, IMG_FMT_GREY8))) {
115 fprintf(stderr, "failed to load image " GROBJ_01_FILENAME "\n");
119 grobj = rleEncode(tmpBitmap, tmpBitmapW, tmpBitmapH);
121 img_free_pixels(tmpBitmap);
134 static void destroy(void)
139 img_free_pixels(background);
144 static void start(long trans_time)
146 lastFrameTime = time_msec;
149 static void stop(long trans_time)
159 static void updateWheel(float t) {
164 static float sin120 = 0.86602540378f;
165 static float cos120 = -0.5f;
170 nx = x * cost - y * sint;
171 ny = y * cost + x * sint;
174 wheelState.circleX[0] = (int)(x + 0.5f) + 16;
175 wheelState.circleY[0] = (int)(y + 0.5f) + 16;
177 /* Rotate by 120 degrees, for the second circle */
178 nx = x * cos120 - y * sin120;
179 ny = y * cos120 + x * sin120;
182 wheelState.circleX[1] = (int)(x + 0.5f) + 16;
183 wheelState.circleY[1] = (int)(y + 0.5f) + 16;
186 nx = x * cos120 - y * sin120;
187 ny = y * cos120 + x * sin120;
190 wheelState.circleX[2] = (int)(x + 0.5f) + 16;
191 wheelState.circleY[2] = (int)(y + 0.5f) + 16;
194 #define WHEEL_CIRCLE_RADIUS 18
195 #define WHEEL_CIRCLE_RADIUS_SQ (WHEEL_CIRCLE_RADIUS * WHEEL_CIRCLE_RADIUS)
197 static unsigned short wheel(int x, int y) {
201 cx = wheelState.circleX[0] - x;
202 cy = wheelState.circleY[0] - y;
203 if (cx*cx + cy*cy < WHEEL_CIRCLE_RADIUS_SQ) count++;
206 cx = wheelState.circleX[1] - x;
207 cy = wheelState.circleY[1] - y;
208 if (cx*cx + cy*cy < WHEEL_CIRCLE_RADIUS_SQ) count++;
211 cx = wheelState.circleX[2] - x;
212 cy = wheelState.circleY[2] - y;
213 if (cx*cx + cy*cy < WHEEL_CIRCLE_RADIUS_SQ) count++;
215 if (count >= 2) return 0xFFFF;
220 static void draw(void)
222 int scroll = MIN_SCROLL + (MAX_SCROLL - MIN_SCROLL) * mouse_x / fb_width;
223 unsigned short *dst = backBuffer + PIXEL_PADDING;
224 unsigned short *src = background + scroll;
230 lastFrameDuration = (time_msec - lastFrameTime) / 1000.0f;
231 lastFrameTime = time_msec;
233 /* Update mini-effects here */
234 updateWheel(time_msec / 1000.0f);
236 /* First, render the horizon */
237 for (scanline = 0; scanline < HORIZON_HEIGHT; scanline++) {
238 memcpy(dst, src, fb_width * 2);
243 /* Create scroll offsets for all scanlines of the normalmap */
244 updateScrollTables(lastFrameDuration);
246 /* Render the baked reflection one scanline below its place, so that
247 * the displacement that follows will be done in a cache-friendly way
249 src -= PIXEL_PADDING; /* We want to also fill the PADDING pixels here */
250 dst = backBuffer + (HORIZON_HEIGHT + 1) * BB_SIZE;
251 for (scanline = 0; scanline < REFLECTION_HEIGHT; scanline++) {
252 memcpy(dst, src, (fb_width + PIXEL_PADDING) * 2);
257 /* Blit reflections first, to be displaced */
258 for (i = 0; i < 5; i++) rleBlitScaleInv(backBuffer + PIXEL_PADDING, fb_width, fb_height, BB_SIZE, grobj, 134 + (i-3) * 60, 235, 1.0f, 1.8f);
260 /* Perform displacement */
261 dst = backBuffer + HORIZON_HEIGHT * BB_SIZE + PIXEL_PADDING;
262 src = dst + BB_SIZE; /* The pixels to be displaced are 1 scanline below */
263 dispScanline = displacementMap;
264 for (scanline = 0; scanline < REFLECTION_HEIGHT; scanline++) {
265 for (i = 0; i < fb_width; i++) {
266 d = dispScanline[(i + scrollTableRounded[scanline]) % scrollModTable[scanline]];
270 dst += BB_SIZE - fb_width;
271 dispScanline += backgroundW;
274 /* Then after displacement, blit the objects */
275 for (i = 0; i < 5; i++) rleBlit(backBuffer + PIXEL_PADDING, fb_width, fb_height, BB_SIZE, grobj, 134 + (i-3) * 60, 100);
277 for (scanline = 0; scanline < 32; scanline++) {
278 for (i = 0; i < 32; i++) {
279 backBuffer[PIXEL_PADDING + scanline * BB_SIZE + i] = wheel(i, scanline);
283 /* Blit effect to framebuffer */
284 src = backBuffer + PIXEL_PADDING;
286 for (scanline = 0; scanline < fb_height; scanline++) {
287 memcpy(dst, src, fb_width * 2);
295 /* src and dst can be the same */
296 static void convert32To16(unsigned int *src32, unsigned short *dst16, unsigned int pixelCount) {
300 *dst16++ = ((p << 8) & 0xF800) /* R */
301 | ((p >> 5) & 0x07E0) /* G */
302 | ((p >> 19) & 0x001F); /* B */
307 /* Normal map preprocessing */
308 /* Scale normal with depth and unpack R component (horizontal component) */
309 static void processNormal() {
313 short maxDisplacement = 0;
314 short minDisplacement = 256;
317 unsigned int *normalmap = (unsigned int*)background;
318 normalmap += NORMALMAP_SCANLINE * backgroundW;
319 dst = (unsigned short*)normalmap;
320 displacementMap = (short*)dst;
321 dst2 = displacementMap;
323 for (scanline = 0; scanline < REFLECTION_HEIGHT; scanline++) {
324 scrollModTable[scanline] = (int) (backgroundW / scrollScaleTable[scanline] + 0.5f);
325 for (i = 0; i < backgroundW; i++) {
326 x = (int)(i * scrollScaleTable[scanline] + 0.5f);
327 if (x < backgroundW) {
328 *dst = (unsigned short)(normalmap[x] >> 8) & 0xFF;
329 if ((short)*dst > maxDisplacement) maxDisplacement = (short)(*dst);
330 if ((short)*dst < minDisplacement) minDisplacement = (short)(*dst);
336 normalmap += backgroundW;
339 if (maxDisplacement == minDisplacement) {
340 printf("Warning: grise normalmap fucked up\n");
344 /* Second pass - subtract half maximum displacement to displace in both directions */
345 for (scanline = 0; scanline < REFLECTION_HEIGHT; scanline++) {
346 for (i = 0; i < backgroundW; i++) {
347 /* Remember that MIN_SCROLL is the padding around the screen, so ti's the maximum displacement we can get (positive & negative) */
348 *dst2 = 2 * MAX_DISPLACEMENT * (*dst2 - minDisplacement) / (maxDisplacement - minDisplacement) - MAX_DISPLACEMENT;
349 *dst2 = (short)((float)*dst2 / scrollScaleTable[scanline] + 0.5f); /* Displacements must also scale with distance*/
355 static float distanceScale(int scanline) {
357 farScale = (float)NEAR_SCROLL_SPEED / (float)FAR_SCROLL_SPEED;
358 t = (float)scanline / ((float)REFLECTION_HEIGHT - 1);
359 return 1.0f / (1.0f / farScale + (1.0f - 1.0f / farScale) * t);
362 static void initScrollTables() {
364 for (i = 0; i < REFLECTION_HEIGHT; i++) {
365 scrollScaleTable[i] = distanceScale(i);
366 scrollTable[i] = 0.0f;
367 scrollTableRounded[i] = 0;
372 static void updateScrollTables(float dt) {
375 nearScrollAmount += dt * NEAR_SCROLL_SPEED;
376 nearScrollAmount = (float) fmod(nearScrollAmount, 512.0f);
378 for (i = 0; i < REFLECTION_HEIGHT; i++) {
379 scrollTable[i] = nearScrollAmount / scrollScaleTable[i];
380 scrollTableRounded[i] = (int)(scrollTable[i] + 0.5f) % scrollModTable[i];
384 /* -------------------------------------------------------------------------------------------------
386 * -------------------------------------------------------------------------------------------------
388 /* Limit streak count per scanline so we can directly jump to specific scanline */
389 #define RLE_STREAKS_PER_SCANLINE 4
390 /* Every streak is encoded by 2 bytes: offset and count of black pixels in the streak */
391 #define RLE_BYTES_PER_SCANLINE RLE_STREAKS_PER_SCANLINE * 2
392 #define RLE_FILL_COLOR 0
393 #define RLE_FILL_COLOR_32 ((RLE_FILL_COLOR << 16) | RLE_FILL_COLOR)
395 #define RLE_FIXED_BITS 16
397 static RLEBitmap rleCreate(unsigned int w, unsigned int h) {
402 /* Add some padding at the end of the buffer, with the worst case for a scanline (w/2 streaks) */
403 ret.scans = (unsigned char*) calloc(h * RLE_BYTES_PER_SCANLINE + w, 1);
408 static void rleDestroy(RLEBitmap b) {
412 static RLEBitmap rleEncode(unsigned char *pixels, unsigned int w, unsigned int h) {
419 unsigned char *output;
421 /* https://www.youtube.com/watch?v=RKMR02o1I88&feature=youtu.be&t=55 */
422 ret = rleCreate(w, h);
424 for (scanline = 0; scanline < h; scanline++) {
425 output = ret.scans + scanline * RLE_BYTES_PER_SCANLINE;
427 for (i = 0; i < w; i++) {
430 if (counter >= PIXEL_PADDING) {
431 *output++ = (unsigned char) counter;
433 *output++ = (unsigned char)accum;
438 *output++ = (unsigned char)accum;
445 *output++ = (unsigned char)counter;
457 *output++ = (unsigned char)counter;
466 static void rleBlit(unsigned short *dst, int dstW, int dstH, int dstStride,
467 RLEBitmap bitmap, int blitX, int blitY)
471 int streakLength = 0;
473 unsigned char *input = bitmap.scans;
474 unsigned short *output;
475 unsigned int *output32;
477 dst += blitX + blitY * dstStride;
479 for (scanline = blitY; scanline < blitY + bitmap.h; scanline++) {
480 if (scanline < 0 || scanline >= dstH) continue;
481 for (streak = 0; streak < RLE_STREAKS_PER_SCANLINE; streak++) {
482 streakPos = *input++;
483 streakLength = *input++;
485 if ((streakPos + blitX) <= 0) continue;
487 output = dst + streakPos;
489 /* Check if we need to write the first pixel as 16bit */
490 if (streakLength % 2) {
491 *output++ = RLE_FILL_COLOR;
494 /* Then, write 2 pixels at a time */
496 output32 = (unsigned int*) output;
497 while (streakLength--) {
498 *output32++ = RLE_FILL_COLOR_32;
506 static void interpolateScan(unsigned char *output, unsigned char *a, unsigned char *b, float t) {
507 static int div = 1 << 23;
511 ti = (*((unsigned int*)&t)) & 0x7FFFFF;
513 for (i = 0; i < RLE_BYTES_PER_SCANLINE; i++) {
522 *output++ = ((*b++ * ti) + (*a++ * (div - ti))) >> 23;
528 static void rleBlitScale(unsigned short *dst, int dstW, int dstH, int dstStride,
529 RLEBitmap bitmap, int blitX, int blitY, float scaleX, float scaleY)
533 int streakLength = 0;
535 unsigned short *output;
536 unsigned int *output32;
537 unsigned char *input;
538 int scanlineCounter = 0;
539 static unsigned char scan[512];
541 int blitW = (int) (bitmap.w * scaleX + 0.5f);
542 int blitH = (int)(bitmap.h * scaleY + 0.5f);
544 /* From this point on, scaleY will be inverted */
545 scaleY = 1.0f / scaleY;
547 int scaleXFixed = (int)(scaleX * (float)(1 << RLE_FIXED_BITS) + 0.5f);
549 dst += blitX + blitY * dstStride;
551 for (scanline = blitY; scanline < blitY + blitH; scanline++) {
552 float normalScan = scanlineCounter * scaleY; /* ScaleY is inverted */
553 unsigned char *scan0 = bitmap.scans + RLE_BYTES_PER_SCANLINE * (int)normalScan;
554 unsigned char *scan1 = scan0 + RLE_BYTES_PER_SCANLINE;
555 normalScan -= (int)normalScan;
556 interpolateScan(scan, scan0, scan1, normalScan);
560 if (scanline < 0 || scanline >= dstH) continue;
561 for (streak = 0; streak < RLE_STREAKS_PER_SCANLINE; streak++) {
562 streakPos = (*input++ * scaleXFixed) >> RLE_FIXED_BITS;
563 streakLength = (*input++ * scaleXFixed) >> RLE_FIXED_BITS;
565 if ((streakPos + blitX) <= 0) continue;
567 output = dst + streakPos;
569 /* Check if we need to write the first pixel as 16bit */
570 if (streakLength % 2) {
571 *output++ = RLE_FILL_COLOR;
574 /* Then, write 2 pixels at a time */
576 output32 = (unsigned int*)output;
577 while (streakLength--) {
578 *output32++ = RLE_FILL_COLOR_32;
588 static void rleBlitScaleInv(unsigned short *dst, int dstW, int dstH, int dstStride,
589 RLEBitmap bitmap, int blitX, int blitY, float scaleX, float scaleY)
593 int streakLength = 0;
595 unsigned short *output;
596 unsigned int *output32;
597 unsigned char *input;
598 int scanlineCounter = 0;
599 static unsigned char scan[512];
601 int blitW = (int)(bitmap.w * scaleX + 0.5f);
602 int blitH = (int)(bitmap.h * scaleY + 0.5f);
604 /* From this point on, scaleY will be inverted */
605 scaleY = 1.0f / scaleY;
607 int scaleXFixed = (int)(scaleX * (float)(1 << RLE_FIXED_BITS) + 0.5f);
609 dst += blitX + blitY * dstStride;
611 for (scanline = blitY; scanline > blitY - blitH; scanline--) {
612 float normalScan = scanlineCounter * scaleY; /* ScaleY is inverted */
613 unsigned char *scan0 = bitmap.scans + RLE_BYTES_PER_SCANLINE * (int)normalScan;
614 unsigned char *scan1 = scan0 + RLE_BYTES_PER_SCANLINE;
615 normalScan -= (int)normalScan;
616 interpolateScan(scan, scan0, scan1, normalScan);
620 if (scanline < 0 || scanline >= dstH) continue;
621 for (streak = 0; streak < RLE_STREAKS_PER_SCANLINE; streak++) {
622 streakPos = (*input++ * scaleXFixed) >> RLE_FIXED_BITS;
623 streakLength = (*input++ * scaleXFixed) >> RLE_FIXED_BITS;
625 if ((streakPos + blitX) <= 0) continue;
627 output = dst + streakPos;
629 /* Check if we need to write the first pixel as 16bit */
630 if (streakLength % 2) {
631 *output++ = RLE_FILL_COLOR;
634 /* Then, write 2 pixels at a time */
636 output32 = (unsigned int*)output;
637 while (streakLength--) {
638 *output32++ = RLE_FILL_COLOR_32;