reorganized the source code
[dosdemo] / src / scr / grise.c
diff --git a/src/scr/grise.c b/src/scr/grise.c
new file mode 100644 (file)
index 0000000..94e3850
--- /dev/null
@@ -0,0 +1,691 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include <assert.h>
+#include "imago2.h"
+#include "demo.h"
+#include "screen.h"
+
+/* APPROX. 170 FPS Minimum */
+
+typedef struct {
+       unsigned int w, h;
+       unsigned char *scans;
+} RLEBitmap;
+
+static RLEBitmap *rleCreate(unsigned int w, unsigned int h);
+static void rleDestroy(RLEBitmap *b);
+static void rleBlit(unsigned short *dst, int dstW, int dstH, int dstStride,
+       RLEBitmap *bitmap, int blitX, int blitY);
+static void rleBlitScale(unsigned short *dst, int dstW, int dstH, int dstStride,
+       RLEBitmap *bitmap, int blitX, int blitY, float scaleX, float scaleY);
+static void rleBlitScaleInv(unsigned short *dst, int dstW, int dstH, int dstStride,
+       RLEBitmap *bitmap, int blitX, int blitY, float scaleX, float scaleY);
+static RLEBitmap *rleEncode(RLEBitmap *b, unsigned char *pixels, unsigned int w, unsigned int h);
+
+static void updatePropeller(float t);
+
+#define BG_FILENAME "data/grise.png"
+#define GROBJ_01_FILENAME "data/grobj_01.png"
+
+#define BB_SIZE 512    /* Let's use a power of 2. Maybe we'll zoom/rotate the effect */
+
+/* Every backBuffer scanline is guaranteed to have that many dummy pixels before and after */
+#define PIXEL_PADDING 32
+
+/* Make sure this is less than PIXEL_PADDING*/
+#define MAX_DISPLACEMENT 16
+
+#define MIN_SCROLL PIXEL_PADDING
+#define MAX_SCROLL (backgroundW - fb_width - MIN_SCROLL)
+
+#define FAR_SCROLL_SPEED 15.0f
+#define NEAR_SCROLL_SPEED 120.0f
+
+#define HORIZON_HEIGHT 100
+#define REFLECTION_HEIGHT (240 - HORIZON_HEIGHT)
+
+#define NORMALMAP_SCANLINE 372
+
+static int init(void);
+static void destroy(void);
+static void start(long trans_time);
+static void stop(long trans_time);
+static void draw(void);
+
+static void convert32To16(unsigned int *src32, unsigned short *dst16, unsigned int pixelCount);
+static void processNormal();
+static void initScrollTables();
+static void updateScrollTables(float dt);
+
+
+
+static unsigned short *background = 0;
+static int backgroundW = 0;
+static int backgroundH = 0;
+
+static unsigned int lastFrameTime = 0;
+static float lastFrameDuration = 0.0f;
+
+static short *displacementMap;
+
+static unsigned short *backBuffer;
+
+static float scrollScaleTable[REFLECTION_HEIGHT];
+static float scrollTable[REFLECTION_HEIGHT];
+static int scrollTableRounded[REFLECTION_HEIGHT];
+static int scrollModTable[REFLECTION_HEIGHT];
+static float nearScrollAmount = 0.0f;
+
+static unsigned char miniFXBuffer[1024];
+
+static RLEBitmap *grobj = 0;
+static RLEBitmap *rlePropeller = 0;
+
+static struct screen scr = {
+       "galaxyrise",
+       init,
+       destroy,
+       start,
+       0,
+       draw
+};
+
+struct screen *grise_screen(void)
+{
+       return &scr;
+}
+
+static int init(void)
+{
+       unsigned char *tmpBitmap;
+       int tmpBitmapW, tmpBitmapH;
+
+       /* Allocate back buffer */
+       backBuffer = (unsigned short*) calloc(BB_SIZE * BB_SIZE, sizeof(unsigned short));
+
+       /* grise.png contains the background (horizon), baked reflection and normalmap for displacement */
+       if (!(background = img_load_pixels(BG_FILENAME, &backgroundW, &backgroundH, IMG_FMT_RGBA32))) {
+               fprintf(stderr, "failed to load image " BG_FILENAME "\n");
+               return -1;
+       }
+
+       /* Convert to 16bpp */
+       convert32To16((unsigned int*)background, background, backgroundW * NORMALMAP_SCANLINE); /* Normalmap will keep its 32 bit color */
+
+       /* Load reflected objects */
+       if (!(tmpBitmap = img_load_pixels(GROBJ_01_FILENAME, &tmpBitmapW, &tmpBitmapH, IMG_FMT_GREY8))) {
+               fprintf(stderr, "failed to load image " GROBJ_01_FILENAME "\n");
+               return -1;
+       }
+
+       grobj = rleEncode(0, tmpBitmap, tmpBitmapW, tmpBitmapH);
+
+       img_free_pixels(tmpBitmap);
+
+       initScrollTables();
+
+       processNormal();
+
+       return 0;
+}
+
+static void destroy(void)
+{
+       free(backBuffer);
+       backBuffer = 0;
+
+       img_free_pixels(background);
+
+       rleDestroy(grobj);
+}
+
+static void start(long trans_time)
+{
+       lastFrameTime = time_msec;
+}
+
+
+static void draw(void)
+{
+       int scroll = MIN_SCROLL + (MAX_SCROLL - MIN_SCROLL) * mouse_x / fb_width;
+       unsigned short *dst = backBuffer + PIXEL_PADDING;
+       unsigned short *src = background + scroll;
+       int scanline = 0;
+       int i = 0;
+       short *dispScanline;
+       int d;
+       int accum = 0;
+       int md, sc;
+       int scrolledIndex;
+
+       lastFrameDuration = (time_msec - lastFrameTime) / 1000.0f;
+       lastFrameTime = time_msec;
+
+       /* Update mini-effects here */
+       updatePropeller(4.0f * time_msec / 1000.0f);
+
+       /* First, render the horizon */
+       for (scanline = 0; scanline < HORIZON_HEIGHT; scanline++) {
+               memcpy(dst, src, fb_width * 2);
+               src += backgroundW;
+               dst += BB_SIZE;
+       }
+
+       /* Create scroll offsets for all scanlines of the normalmap */
+       updateScrollTables(lastFrameDuration);
+
+       /* Render the baked reflection one scanline below its place, so that
+        * the displacement that follows will be done in a cache-friendly way
+        */
+       src -= PIXEL_PADDING; /* We want to also fill the PADDING pixels here */
+       dst = backBuffer + (HORIZON_HEIGHT + 1) * BB_SIZE;
+       for (scanline = 0; scanline < REFLECTION_HEIGHT; scanline++) {
+               memcpy(dst, src, (fb_width + PIXEL_PADDING) * 2);
+               src += backgroundW;
+               dst += BB_SIZE;
+       }
+
+       /* Blit reflections first, to be  displaced */
+       for (i = 0; i < 5; i++) rleBlitScaleInv(backBuffer + PIXEL_PADDING, fb_width, fb_height, BB_SIZE, rlePropeller, 134 + (i-3) * 60, 200, 1.0f, 1.8f);
+
+       /* Perform displacement */
+       dst = backBuffer + HORIZON_HEIGHT * BB_SIZE + PIXEL_PADDING;
+       src = dst + BB_SIZE; /* The pixels to be displaced are 1 scanline below */
+       dispScanline = displacementMap;
+       for (scanline = 0; scanline < REFLECTION_HEIGHT; scanline++) {
+
+               md = scrollModTable[scanline];
+               sc = scrollTableRounded[scanline];
+               accum = 0;
+
+               for (i = 0; i < fb_width; i++) {
+                       /* Try to immitate modulo without the division */
+                       if (i == md) accum += md;
+                       scrolledIndex = i - accum + sc;
+                       if (scrolledIndex >= md) scrolledIndex -= md;
+
+                       /* Displace */
+                       d = dispScanline[scrolledIndex];
+                       *dst++ = src[i + d];
+               }
+               src += backgroundW;
+               dst += BB_SIZE - fb_width;
+               dispScanline += backgroundW;
+       }
+
+       /* Then after displacement, blit the objects */
+       for (i = 0; i < 5; i++) rleBlit(backBuffer + PIXEL_PADDING, fb_width, fb_height, BB_SIZE, rlePropeller, 134 + (i-3) * 60, 100);
+
+       /* Blit effect to framebuffer */
+       src = backBuffer + PIXEL_PADDING;
+       dst = fb_pixels;
+       for (scanline = 0; scanline < fb_height; scanline++) {
+               memcpy(dst, src, fb_width * 2);
+               src += BB_SIZE;
+               dst += fb_width;
+       }
+
+       swap_buffers(0);
+}
+
+/* src and dst can be the same */
+static void convert32To16(unsigned int *src32, unsigned short *dst16, unsigned int pixelCount) {
+       unsigned int p;
+       while (pixelCount) {
+               p = *src32++;
+               *dst16++ =      ((p << 8) & 0xF800)             /* R */
+                       |               ((p >> 5) & 0x07E0)             /* G */
+                       |               ((p >> 19) & 0x001F);   /* B */
+               pixelCount--;
+       }
+}
+
+/* Normal map preprocessing */
+/* Scale normal with depth and unpack R component (horizontal component) */
+static void processNormal() {
+       int scanline;
+       int i;
+       int x;
+       short maxDisplacement = 0;
+       short minDisplacement = 256;
+       unsigned short *dst;
+       short *dst2;
+       unsigned int *normalmap = (unsigned int*)background;
+       normalmap += NORMALMAP_SCANLINE * backgroundW;
+       dst = (unsigned short*)normalmap;
+       displacementMap = (short*)dst;
+       dst2 = displacementMap;
+
+       for (scanline = 0; scanline < REFLECTION_HEIGHT; scanline++) {
+               scrollModTable[scanline] = (int) (backgroundW / scrollScaleTable[scanline] + 0.5f);
+               for (i = 0; i < backgroundW; i++) {
+                       x = (int)(i * scrollScaleTable[scanline] + 0.5f);
+                       if (x < backgroundW) {
+                               *dst = (unsigned short)(normalmap[x] >> 8) & 0xFF;
+                               if ((short)*dst > maxDisplacement) maxDisplacement = (short)(*dst);
+                               if ((short)*dst < minDisplacement) minDisplacement = (short)(*dst);
+                       } else {
+                               *dst = 0;
+                       }
+                       dst++;
+               }
+               normalmap += backgroundW;
+       }
+
+       if (maxDisplacement == minDisplacement) {
+               printf("Warning: grise normalmap fucked up\n");
+               return;
+       }
+
+       /* Second pass - subtract half maximum displacement to displace in both directions */
+       for (scanline = 0; scanline < REFLECTION_HEIGHT; scanline++) {
+               for (i = 0; i < backgroundW; i++) {
+                       /* Remember that MIN_SCROLL is the padding around the screen, so ti's the maximum displacement we can get (positive & negative) */
+                       *dst2 = 2 * MAX_DISPLACEMENT * (*dst2 - minDisplacement) / (maxDisplacement - minDisplacement) - MAX_DISPLACEMENT;
+                       *dst2 = (short)((float)*dst2 / scrollScaleTable[scanline] + 0.5f); /* Displacements must also scale with distance*/
+                       dst2++;
+               }
+       }
+}
+
+static float distanceScale(int scanline) {
+       float farScale, t;
+       farScale = (float)NEAR_SCROLL_SPEED / (float)FAR_SCROLL_SPEED;
+       t = (float)scanline / ((float)REFLECTION_HEIGHT - 1);
+       return 1.0f / (1.0f / farScale + (1.0f - 1.0f / farScale) * t);
+}
+
+static void initScrollTables() {
+       int i = 0;
+       for (i = 0; i < REFLECTION_HEIGHT; i++) {
+               scrollScaleTable[i] = distanceScale(i);
+               scrollTable[i] = 0.0f;
+               scrollTableRounded[i] = 0;
+       }
+}
+
+
+static void updateScrollTables(float dt) {
+       int i = 0;
+
+       nearScrollAmount += dt * NEAR_SCROLL_SPEED;
+       nearScrollAmount = (float) fmod(nearScrollAmount, 512.0f);
+
+       for (i = 0; i < REFLECTION_HEIGHT; i++) {
+               scrollTable[i] = nearScrollAmount / scrollScaleTable[i];
+               scrollTableRounded[i] = (int)(scrollTable[i] + 0.5f) % scrollModTable[i];
+       }
+}
+
+/* -------------------------------------------------------------------------------------------------
+ *                                   RLE STUFF
+ * -------------------------------------------------------------------------------------------------
+ */
+/* Limit streak count per scanline so we can directly jump to specific scanline */
+#define RLE_STREAKS_PER_SCANLINE 4
+/* Every streak is encoded by 2 bytes: offset and count of black pixels in the streak */
+#define RLE_BYTES_PER_SCANLINE RLE_STREAKS_PER_SCANLINE * 2
+#define RLE_FILL_COLOR 0
+#define RLE_FILL_COLOR_32 ((RLE_FILL_COLOR << 16) | RLE_FILL_COLOR)
+
+#define RLE_FIXED_BITS 16
+
+static int rleByteCount(int w, int h) {
+       return h * RLE_BYTES_PER_SCANLINE + w;
+}
+
+static RLEBitmap *rleCreate(unsigned int w, unsigned int h) {
+       RLEBitmap *ret = (RLEBitmap*)malloc(sizeof(RLEBitmap));
+       ret->w = w;
+       ret->h = h;
+
+       /* Add some padding at the end of the buffer, with the worst case for a scanline (w/2 streaks) */
+       ret->scans = (unsigned char*) calloc(rleByteCount(w, h), 1);
+
+       return ret;
+}
+
+static void rleDestroy(RLEBitmap *b) {
+       if (!b) return;
+       free(b->scans);
+       free(b);
+}
+
+static RLEBitmap *rleEncode(RLEBitmap *b, unsigned char *pixels, unsigned int w, unsigned int h) {
+       int scanline;
+       int i;
+       int penActive = 0;
+       int counter = 0;
+       int accum = 0;
+       unsigned char *output;
+
+       /* https://www.youtube.com/watch?v=RKMR02o1I88&feature=youtu.be&t=55 */
+       if (!b) b = rleCreate(w, h);
+       else memset(b->scans, 0, rleByteCount(b->w, b->h)); /* The following code assumes cleared array */
+
+       for (scanline = 0; scanline < h; scanline++) {
+               output = b->scans + scanline * RLE_BYTES_PER_SCANLINE;
+               accum = 0;
+               for (i = 0; i < w; i++) {
+                       if (*pixels++) {
+                               if (penActive) {
+                                       if (counter >= PIXEL_PADDING) {
+                                               *output++ = (unsigned char) counter;
+                                               counter = 0;
+                                               *output++ = (unsigned char)accum;
+                                       }
+                                       counter++;
+                                       accum++;
+                               } else {
+                                       *output++ = (unsigned char)accum;
+                                       counter = 1;
+                                       accum++;
+                                       penActive = 1;
+                               }
+                       } else {
+                               if (penActive) {
+                                       *output++ = (unsigned char)counter;
+                                       counter = 1;
+                                       accum++;
+                                       penActive = 0;
+                               } else {
+                                       counter++;
+                                       accum++;
+                               }
+                       }
+               }
+
+               if (penActive) {
+                       *output++ = (unsigned char)counter;
+               }
+               penActive = 0;
+               counter = 0;
+       }
+
+       return b;
+}
+
+static void rleDistributeStreaks(RLEBitmap *bitmap) {
+       int scanline, halfW = bitmap->w >> 1;
+       unsigned char *ptr, tmp;
+
+       ptr = bitmap->scans;
+       for (scanline = 0; scanline < bitmap->h; scanline++) {
+               if (ptr[0] >= halfW) {
+                       tmp = ptr[0];
+                       ptr[0] = ptr[6];
+                       ptr[6] = tmp;
+                       tmp = ptr[1];
+                       ptr[1] = ptr[7];
+                       ptr[7] = tmp;
+               }
+
+               ptr += 8;
+       }
+}
+
+static void rleBlit(unsigned short *dst, int dstW, int dstH, int dstStride,
+       RLEBitmap *bitmap, int blitX, int blitY)
+{
+       int scanline = 0;
+       int streakPos = 0;
+       int streakLength = 0;
+       int streak = 0;
+       unsigned char *input = bitmap->scans;
+       unsigned short *output;
+       unsigned int *output32;
+
+       dst += blitX + blitY * dstStride;
+
+       for (scanline = blitY; scanline < blitY + bitmap->h; scanline++) {
+               if (scanline < 0 || scanline >= dstH) continue;
+               for (streak = 0; streak < RLE_STREAKS_PER_SCANLINE; streak++) {
+                       streakPos = *input++;
+                       streakLength = *input++;
+
+                       if ((streakPos + blitX) <= 0) continue;
+
+                       output = dst + streakPos;
+
+                       /* Check if we need to write the first pixel as 16bit */
+                       if (streakLength % 2) {
+                               *output++ = RLE_FILL_COLOR;
+                       }
+
+                       /* Then, write 2 pixels at a time */
+                       streakLength >>= 1;
+                       output32 = (unsigned int*) output;
+                       while (streakLength--) {
+                               *output32++ = RLE_FILL_COLOR_32;
+                       }
+               }
+
+               dst += dstStride;
+       }
+}
+
+static void interpolateScan(unsigned char *output, unsigned char *a, unsigned char *b, float t) {
+       static int div = 1 << 23;
+       int ti, i;
+
+       t += 1.0f;
+       ti = (*((unsigned int*)&t)) & 0x7FFFFF;
+
+       for (i = 0; i < RLE_BYTES_PER_SCANLINE; i++) {
+               if (*a == 0) {
+                       *output++ = *b++;
+                       a++;
+               } else {
+                       if (*b == 0) {
+                               *output++ = *a++;
+                               b++;
+                       } else {
+                               *output++ = ((*b++ * ti) + (*a++ * (div - ti))) >> 23;
+                       }
+               }
+       }
+}
+
+static void rleBlitScale(unsigned short *dst, int dstW, int dstH, int dstStride,
+       RLEBitmap *bitmap, int blitX, int blitY, float scaleX, float scaleY)
+{
+       int scanline = 0;
+       int streakPos = 0;
+       int streakLength = 0;
+       int streak = 0;
+       unsigned short *output;
+       unsigned int *output32;
+       unsigned char *input;
+       int scanlineCounter = 0;
+       int scaleXFixed;
+       static unsigned char scan[512];
+
+       /*int blitW = (int)(bitmap->w * scaleX + 0.5f);*/
+       int blitH = (int)(bitmap->h * scaleY + 0.5f);
+
+       /* From this point on, scaleY will be inverted */
+       scaleY = 1.0f / scaleY;
+
+       scaleXFixed = (int)(scaleX * (float)(1 << RLE_FIXED_BITS) + 0.5f);
+
+       dst += blitX + blitY * dstStride;
+
+       for (scanline = blitY; scanline < blitY + blitH; scanline++) {
+               float normalScan = scanlineCounter * scaleY; /* ScaleY  is inverted */
+               unsigned char *scan0 = bitmap->scans + RLE_BYTES_PER_SCANLINE * (int)normalScan;
+               unsigned char *scan1 = scan0 + RLE_BYTES_PER_SCANLINE;
+               normalScan -= (int)normalScan;
+               interpolateScan(scan, scan0, scan1, normalScan);
+               input = scan;
+               scanlineCounter++;
+
+               if (scanline < 0 || scanline >= dstH) continue;
+               for (streak = 0; streak < RLE_STREAKS_PER_SCANLINE; streak++) {
+                       streakPos = (*input++ * scaleXFixed) >> RLE_FIXED_BITS;
+                       streakLength = (*input++ * scaleXFixed) >> RLE_FIXED_BITS;
+
+                       if ((streakPos + blitX) <= 0) continue;
+
+                       output = dst + streakPos;
+
+                       /* Check if we need to write the first pixel as 16bit */
+                       if (streakLength % 2) {
+                               *output++ = RLE_FILL_COLOR;
+                       }
+
+                       /* Then, write 2 pixels at a time */
+                       streakLength >>= 1;
+                       output32 = (unsigned int*)output;
+                       while (streakLength--) {
+                               *output32++ = RLE_FILL_COLOR_32;
+                       }
+               }
+
+               dst += dstStride;
+       }
+}
+
+
+
+static void rleBlitScaleInv(unsigned short *dst, int dstW, int dstH, int dstStride,
+       RLEBitmap *bitmap, int blitX, int blitY, float scaleX, float scaleY)
+{
+       int scanline = 0;
+       int streakPos = 0;
+       int streakLength = 0;
+       int streak = 0;
+       unsigned short *output;
+       unsigned int *output32;
+       unsigned char *input;
+       int scanlineCounter = 0;
+       int scaleXFixed;
+       static unsigned char scan[512];
+
+       /*int blitW = (int)(bitmap->w * scaleX + 0.5f);*/
+       int blitH = (int)(bitmap->h * scaleY + 0.5f);
+
+       /* From this point on, scaleY will be inverted */
+       scaleY = 1.0f / scaleY;
+
+       scaleXFixed = (int)(scaleX * (float)(1 << RLE_FIXED_BITS) + 0.5f);
+
+       dst += blitX + blitY * dstStride;
+
+       for (scanline = blitY; scanline > blitY - blitH; scanline--) {
+               float normalScan = scanlineCounter * scaleY; /* ScaleY is inverted */
+               unsigned char *scan0 = bitmap->scans + RLE_BYTES_PER_SCANLINE * (int)normalScan;
+               unsigned char *scan1 = scan0 + RLE_BYTES_PER_SCANLINE;
+               normalScan -= (int)normalScan;
+               interpolateScan(scan, scan0, scan1, normalScan);
+               input = scan;
+               scanlineCounter++;
+
+               if (scanline < 0 || scanline >= dstH) continue;
+               for (streak = 0; streak < RLE_STREAKS_PER_SCANLINE; streak++) {
+                       streakPos = (*input++ * scaleXFixed) >> RLE_FIXED_BITS;
+                       streakLength = (*input++ * scaleXFixed) >> RLE_FIXED_BITS;
+
+                       if ((streakPos + blitX) <= 0) continue;
+
+                       output = dst + streakPos;
+
+                       /* Check if we need to write the first pixel as 16bit */
+                       if (streakLength % 2) {
+                               *output++ = RLE_FILL_COLOR;
+                       }
+
+                       /* Then, write 2 pixels at a time */
+                       streakLength >>= 1;
+                       output32 = (unsigned int*)output;
+                       while (streakLength--) {
+                               *output32++ = RLE_FILL_COLOR_32;
+                       }
+               }
+
+               dst -= dstStride;
+       }
+}
+
+/* -------------------------------------------------------------------------------------------------
+*                                   PROPELLER STUFF
+* -------------------------------------------------------------------------------------------------
+*/
+
+#define PROPELLER_CIRCLE_RADIUS 18
+#define PROPELLER_CIRCLE_RADIUS_SQ (PROPELLER_CIRCLE_RADIUS * PROPELLER_CIRCLE_RADIUS)
+
+static struct {
+       int circleX[3];
+       int circleY[3];
+} propellerState;
+
+static void updatePropeller(float t) {
+       int i, j;
+       int cx, cy, count = 0;
+       unsigned char *dst;
+       float x = 0.0f;
+       float y = 18.0f;
+       float nx, ny;
+       float cost, sint;
+       static float sin120 = 0.86602540378f;
+       static float cos120 = -0.5f;
+
+       /* Rotate */
+       sint = sin(t);
+       cost = cos(t);
+       nx = x * cost - y * sint;
+       ny = y * cost + x * sint;
+       x = nx;
+       y = ny;
+       propellerState.circleX[0] = (int)(x + 0.5f) + 16;
+       propellerState.circleY[0] = (int)(y + 0.5f) + 16;
+
+       /* Rotate by 120 degrees, for the second circle */
+       nx = x * cos120 - y * sin120;
+       ny = y * cos120 + x * sin120;
+       x = nx;
+       y = ny;
+       propellerState.circleX[1] = (int)(x + 0.5f) + 16;
+       propellerState.circleY[1] = (int)(y + 0.5f) + 16;
+
+       /* 3rd circle */
+       nx = x * cos120 - y * sin120;
+       ny = y * cos120 + x * sin120;
+       x = nx;
+       y = ny;
+       propellerState.circleX[2] = (int)(x + 0.5f) + 16;
+       propellerState.circleY[2] = (int)(y + 0.5f) + 16;
+
+       /* Write effect to the mini fx buffer*/
+       dst = miniFXBuffer;
+       for (j = 0; j < 32; j++) {
+               for (i = 0; i < 32; i++) {
+                       count = 0;
+
+                       /* First circle */
+                       cx = propellerState.circleX[0] - i;
+                       cy = propellerState.circleY[0] - j;
+                       if (cx*cx + cy*cy < PROPELLER_CIRCLE_RADIUS_SQ) count++;
+
+                       /* 2nd circle */
+                       cx = propellerState.circleX[1] - i;
+                       cy = propellerState.circleY[1] - j;
+                       if (cx*cx + cy*cy < PROPELLER_CIRCLE_RADIUS_SQ) count++;
+
+                       /* 3rd circle */
+                       cx = propellerState.circleX[2] - i;
+                       cy = propellerState.circleY[2] - j;
+                       if (cx*cx + cy*cy < PROPELLER_CIRCLE_RADIUS_SQ) count++;
+
+                       *dst++ = count >= 2;
+               }
+       }
+
+       /* Then, encode to rle */
+       rlePropeller = rleEncode(rlePropeller, miniFXBuffer, 32, 32);
+
+       /* Distribute the produced streaks so that they don't produce garbage when interpolated */
+       rleDistributeStreaks(rlePropeller);
+}