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*) malloc(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)
153 static void draw(void)
155 int scroll = MIN_SCROLL + (MAX_SCROLL - MIN_SCROLL) * mouse_x / fb_width;
156 unsigned short *dst = backBuffer + PIXEL_PADDING;
157 unsigned short *src = background + scroll;
163 lastFrameDuration = (time_msec - lastFrameTime) / 1000.0f;
164 lastFrameTime = time_msec;
166 /* First, render the horizon */
167 for (scanline = 0; scanline < HORIZON_HEIGHT; scanline++) {
168 memcpy(dst, src, fb_width * 2);
173 /* Create scroll offsets for all scanlines of the normalmap */
174 updateScrollTables(lastFrameDuration);
176 /* Render the baked reflection one scanline below its place, so that
177 * the displacement that follows will be done in a cache-friendly way
179 src -= PIXEL_PADDING; /* We want to also fill the PADDING pixels here */
180 dst = backBuffer + (HORIZON_HEIGHT + 1) * BB_SIZE;
181 for (scanline = 0; scanline < REFLECTION_HEIGHT; scanline++) {
182 memcpy(dst, src, (fb_width + PIXEL_PADDING) * 2);
187 /* Blit reflections first, to be displaced */
188 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);
190 /* Perform displacement */
191 dst = backBuffer + HORIZON_HEIGHT * BB_SIZE + PIXEL_PADDING;
192 src = dst + BB_SIZE; /* The pixels to be displaced are 1 scanline below */
193 dispScanline = displacementMap;
194 for (scanline = 0; scanline < REFLECTION_HEIGHT; scanline++) {
195 for (i = 0; i < fb_width; i++) {
196 d = dispScanline[(i + scrollTableRounded[scanline]) % scrollModTable[scanline]];
200 dst += BB_SIZE - fb_width;
201 dispScanline += backgroundW;
204 /* Then after displacement, blit the objects */
205 //for (i = 0; i < 5; i++) rleBlit(backBuffer + PIXEL_PADDING, fb_width, fb_height, BB_SIZE, grobj, 134 + (i-3) * 60, 100);
206 for (i = 0; i < 5; i++) rleBlitScale(backBuffer + PIXEL_PADDING, fb_width, fb_height, BB_SIZE, grobj, 134 + (i - 3) * 120, 0, 1.8f, 1.8f);
208 /* Blit effect to framebuffer */
209 src = backBuffer + PIXEL_PADDING;
211 for (scanline = 0; scanline < fb_height; scanline++) {
212 memcpy(dst, src, fb_width * 2);
217 swap_buffers(fb_pixels);
220 /* src and dst can be the same */
221 static void convert32To16(unsigned int *src32, unsigned short *dst16, unsigned int pixelCount) {
225 *dst16++ = ((p << 8) & 0xF800) /* R */
226 | ((p >> 5) & 0x07E0) /* G */
227 | ((p >> 19) & 0x001F); /* B */
232 /* Normal map preprocessing */
233 /* Scale normal with depth and unpack R component (horizontal component) */
234 static void processNormal() {
238 short maxDisplacement = 0;
239 short minDisplacement = 256;
242 unsigned int *normalmap = (unsigned int*)background;
243 normalmap += NORMALMAP_SCANLINE * backgroundW;
244 dst = (unsigned short*)normalmap;
245 displacementMap = (short*)dst;
246 dst2 = displacementMap;
248 for (scanline = 0; scanline < REFLECTION_HEIGHT; scanline++) {
249 scrollModTable[scanline] = (int) (backgroundW / scrollScaleTable[scanline] + 0.5f);
250 for (i = 0; i < backgroundW; i++) {
251 x = (int)(i * scrollScaleTable[scanline] + 0.5f);
252 if (x < backgroundW) {
253 *dst = (unsigned short)(normalmap[x] >> 8) & 0xFF;
254 if ((short)*dst > maxDisplacement) maxDisplacement = (short)(*dst);
255 if ((short)*dst < minDisplacement) minDisplacement = (short)(*dst);
261 normalmap += backgroundW;
264 if (maxDisplacement == minDisplacement) {
265 printf("Warning: grise normalmap fucked up\n");
269 /* Second pass - subtract half maximum displacement to displace in both directions */
270 for (scanline = 0; scanline < REFLECTION_HEIGHT; scanline++) {
271 for (i = 0; i < backgroundW; i++) {
272 /* Remember that MIN_SCROLL is the padding around the screen, so ti's the maximum displacement we can get (positive & negative) */
273 *dst2 = 2 * MAX_DISPLACEMENT * (*dst2 - minDisplacement) / (maxDisplacement - minDisplacement) - MAX_DISPLACEMENT;
274 *dst2 = (short)((float)*dst2 / scrollScaleTable[scanline] + 0.5f); /* Displacements must also scale with distance*/
280 static float distanceScale(int scanline) {
282 farScale = (float)NEAR_SCROLL_SPEED / (float)FAR_SCROLL_SPEED;
283 t = (float)scanline / ((float)REFLECTION_HEIGHT - 1);
284 return 1.0f / (1.0f / farScale + (1.0f - 1.0f / farScale) * t);
287 static void initScrollTables() {
289 for (i = 0; i < REFLECTION_HEIGHT; i++) {
290 scrollScaleTable[i] = distanceScale(i);
291 scrollTable[i] = 0.0f;
292 scrollTableRounded[i] = 0;
297 static void updateScrollTables(float dt) {
300 nearScrollAmount += dt * NEAR_SCROLL_SPEED;
301 nearScrollAmount = (float) fmod(nearScrollAmount, 512.0f);
303 for (i = 0; i < REFLECTION_HEIGHT; i++) {
304 scrollTable[i] = nearScrollAmount / scrollScaleTable[i];
305 scrollTableRounded[i] = (int)(scrollTable[i] + 0.5f) % scrollModTable[i];
309 /* -------------------------------------------------------------------------------------------------
311 * -------------------------------------------------------------------------------------------------
313 /* Limit streak count per scanline so we can directly jump to specific scanline */
314 #define RLE_STREAKS_PER_SCANLINE 4
315 /* Every streak is encoded by 2 bytes: offset and count of black pixels in the streak */
316 #define RLE_BYTES_PER_SCANLINE RLE_STREAKS_PER_SCANLINE * 2
317 #define RLE_FILL_COLOR 0xFF00
318 #define RLE_FILL_COLOR_32 ((RLE_FILL_COLOR << 16) | RLE_FILL_COLOR)
320 #define RLE_FIXED_BITS 16
322 static RLEBitmap rleCreate(unsigned int w, unsigned int h) {
327 /* Add some padding at the end of the buffer, with the worst case for a scanline (w/2 streaks) */
328 ret.scans = (unsigned char*) calloc(h * RLE_BYTES_PER_SCANLINE + w, 1);
333 static void rleDestroy(RLEBitmap b) {
337 static RLEBitmap rleEncode(unsigned char *pixels, unsigned int w, unsigned int h) {
344 unsigned char *output;
346 /* https://www.youtube.com/watch?v=RKMR02o1I88&feature=youtu.be&t=55 */
347 ret = rleCreate(w, h);
349 for (scanline = 0; scanline < h; scanline++) {
350 output = ret.scans + scanline * RLE_BYTES_PER_SCANLINE;
352 for (i = 0; i < w; i++) {
355 if (counter >= PIXEL_PADDING) {
356 *output++ = (unsigned char) counter;
358 *output++ = (unsigned char)accum;
363 *output++ = (unsigned char)accum;
370 *output++ = (unsigned char)counter;
382 *output++ = (unsigned char)counter;
391 static void rleBlit(unsigned short *dst, int dstW, int dstH, int dstStride,
392 RLEBitmap bitmap, int blitX, int blitY)
396 int streakLength = 0;
398 unsigned char *input = bitmap.scans;
399 unsigned short *output;
400 unsigned int *output32;
402 dst += blitX + blitY * dstStride;
404 for (scanline = blitY; scanline < blitY + bitmap.h; scanline++) {
405 if (scanline < 0 || scanline >= dstH) continue;
406 for (streak = 0; streak < RLE_STREAKS_PER_SCANLINE; streak++) {
407 streakPos = *input++;
408 streakLength = *input++;
410 if ((streakPos + blitX) <= 0) continue;
412 output = dst + streakPos;
414 /* Check if we need to write the first pixel as 16bit */
415 if (streakLength % 2) {
416 *output++ = RLE_FILL_COLOR;
419 /* Then, write 2 pixels at a time */
421 output32 = (unsigned int*) output;
422 while (streakLength--) {
423 *output32++ = RLE_FILL_COLOR_32;
431 static void interpolateScan(unsigned char *output, unsigned char *a, unsigned char *b, float t) {
432 static int div = 1 << 23;
436 ti = (*((unsigned int*)&t)) & 0x7FFFFF;
438 for (i = 0; i < RLE_BYTES_PER_SCANLINE; i++) {
447 *output++ = ((*b++ * ti) + (*a++ * (div - ti))) >> 23;
453 static void rleBlitScale(unsigned short *dst, int dstW, int dstH, int dstStride,
454 RLEBitmap bitmap, int blitX, int blitY, float scaleX, float scaleY)
458 int streakLength = 0;
460 unsigned short *output;
461 unsigned int *output32;
462 unsigned char *input;
463 int scanlineCounter = 0;
464 static unsigned char scan[512];
466 int blitW = (int) (bitmap.w * scaleX + 0.5f);
467 int blitH = (int)(bitmap.h * scaleY + 0.5f);
469 /* From this point on, scaleY will be inverted */
470 scaleY = 1.0f / scaleY;
472 int scaleXFixed = (int)(scaleX * (float)(1 << RLE_FIXED_BITS) + 0.5f);
474 dst += blitX + blitY * dstStride;
476 for (scanline = blitY; scanline < blitY + blitH; scanline++) {
477 float normalScan = scanlineCounter * scaleY; /* ScaleY is inverted */
478 unsigned char *scan0 = bitmap.scans + RLE_BYTES_PER_SCANLINE * (int)normalScan;
479 unsigned char *scan1 = scan0 + RLE_BYTES_PER_SCANLINE;
480 normalScan -= (int)normalScan;
481 interpolateScan(scan, scan0, scan1, normalScan);
485 if (scanline < 0 || scanline >= dstH) continue;
486 for (streak = 0; streak < RLE_STREAKS_PER_SCANLINE; streak++) {
487 streakPos = (*input++ * scaleXFixed) >> RLE_FIXED_BITS;
488 streakLength = (*input++ * scaleXFixed) >> RLE_FIXED_BITS;
490 if ((streakPos + blitX) <= 0) continue;
492 output = dst + streakPos;
494 /* Check if we need to write the first pixel as 16bit */
495 if (streakLength % 2) {
496 *output++ = RLE_FILL_COLOR;
499 /* Then, write 2 pixels at a time */
501 output32 = (unsigned int*)output;
502 while (streakLength--) {
503 *output32++ = RLE_FILL_COLOR_32;
513 static void rleBlitScaleInv(unsigned short *dst, int dstW, int dstH, int dstStride,
514 RLEBitmap bitmap, int blitX, int blitY, float scaleX, float scaleY)
518 int streakLength = 0;
520 unsigned short *output;
521 unsigned int *output32;
522 unsigned char *input;
523 int scanlineCounter = 0;
524 static unsigned char scan[512];
526 int blitW = (int)(bitmap.w * scaleX + 0.5f);
527 int blitH = (int)(bitmap.h * scaleY + 0.5f);
529 /* From this point on, scaleY will be inverted */
530 scaleY = 1.0f / scaleY;
532 int scaleXFixed = (int)(scaleX * (float)(1 << RLE_FIXED_BITS) + 0.5f);
534 dst += blitX + blitY * dstStride;
536 for (scanline = blitY; scanline > blitY - blitH; scanline--) {
537 float normalScan = scanlineCounter * scaleY; /* ScaleY is inverted */
538 unsigned char *scan0 = bitmap.scans + RLE_BYTES_PER_SCANLINE * (int)normalScan;
539 unsigned char *scan1 = scan0 + RLE_BYTES_PER_SCANLINE;
540 normalScan -= (int)normalScan;
541 interpolateScan(scan, scan0, scan1, normalScan);
545 if (scanline < 0 || scanline >= dstH) continue;
546 for (streak = 0; streak < RLE_STREAKS_PER_SCANLINE; streak++) {
547 streakPos = (*input++ * scaleXFixed) >> RLE_FIXED_BITS;
548 streakLength = (*input++ * scaleXFixed) >> RLE_FIXED_BITS;
550 if ((streakPos + blitX) <= 0) continue;
552 output = dst + streakPos;
554 /* Check if we need to write the first pixel as 16bit */
555 if (streakLength % 2) {
556 *output++ = RLE_FILL_COLOR;
559 /* Then, write 2 pixels at a time */
561 output32 = (unsigned int*)output;
562 while (streakLength--) {
563 *output32++ = RLE_FILL_COLOR_32;