Implemented RLE compression for reflected objects

[dosdemo] / src / grise.c

diff --git a/src/grise.c b/src/grise.c
index 7e57508..539c06d 100644 (file)
--- a/src/grise.c
+++ b/src/grise.c
@@ -10,6 +10,7 @@
 /* APPROX. 170 FPS Minimum */
 
 #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 */
 
@@ -38,6 +39,8 @@ static void processNormal();
 static void initScrollTables();
 static void updateScrollTables(float dt);
 
+static void rleEncode(unsigned char *pixels, unsigned int w, unsigned int h);
+
 static unsigned short *background = 0;
 static unsigned int backgroundW = 0;
 static unsigned int backgroundH = 0;
@@ -56,7 +59,7 @@ static int scrollModTable[REFLECTION_HEIGHT];
 static float nearScrollAmount = 0.0f;
 
 static struct screen scr = {
-       "Galaxy rise",
+       "galaxyrise",
        init,
        destroy,
        start,
@@ -72,9 +75,13 @@ struct screen *grise_screen(void)
 
 static int init(void)
 {
+       unsigned char *reflectedObject;
+       int reflectedObjectW, reflectedObjectH;
+
        /* Allocate back buffer */
        backBuffer = (unsigned short*) malloc(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;
@@ -83,6 +90,16 @@ static int init(void)
        /* Convert to 16bpp */
        convert32To16((unsigned int*)background, background, backgroundW * NORMALMAP_SCANLINE); /* Normalmap will keep its 32 bit color */
 
+       /* Load reflected objects */
+       if (!(reflectedObject = img_load_pixels(GROBJ_01_FILENAME, &reflectedObjectW, &reflectedObjectH, IMG_FMT_GREY8))) {
+               fprintf(stderr, "failed to load image " GROBJ_01_FILENAME "\n");
+               return -1;
+       }
+
+       rleEncode(reflectedObject, reflectedObjectW, reflectedObjectH);
+
+       img_free_pixels(reflectedObject);
+
        initScrollTables();
 
        processNormal();
@@ -131,17 +148,28 @@ static void draw(void)
                dst += BB_SIZE;
        }
        
-       /* Create scroll opffsets for all scanlines of the normalmap */
+       /* Create scroll offsets for all scanlines of the normalmap */
        updateScrollTables(lastFrameDuration);
 
-       /* Then, render the reflection under the horizon */
-       /* dst is already in place */
-       src = background + HORIZON_HEIGHT * backgroundW;
+       /* 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;
+       }
+       
+       /* 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++) {
                for (i = 0; i < fb_width; i++) {
                        d = dispScanline[(i + scrollTableRounded[scanline]) % scrollModTable[scanline]];
-                       *dst++ = src[i + scroll + d];
+                       *dst++ = src[i + d];
                }
                src += backgroundW;
                dst += BB_SIZE - fb_width;
@@ -246,3 +274,45 @@ static void updateScrollTables(float dt) {
                scrollTableRounded[i] = (int)(scrollTable[i] + 0.5f) % scrollModTable[i];
        }
 }
+
+static void rleEncode(unsigned char *pixels, unsigned int w, unsigned int h) {
+       int scanline;
+       int i;
+       int penActive = 0;
+       int counter = 0;
+
+       for (scanline = 0; scanline < h; scanline++) {
+               for (i = 0; i < w; i++) {
+                       if (*pixels++) {
+                               if (penActive) {
+                                       if (counter >= PIXEL_PADDING) {
+                                               printf("W %d ", counter);
+                                               counter = 0;
+                                               printf("I %d ", counter);
+                                       }
+                                       counter++;
+                               } else {
+                                       counter++;
+                                       printf("I %d ", counter);
+                                       counter = 1;
+                                       penActive = 1;
+                               }
+                       } else {
+                               if (penActive) {
+                                       printf("W %d ", counter);
+                                       counter = 0;
+                                       penActive = 0;
+                               } else {
+                                       counter++;
+                               }
+                       }
+               }
+
+               if (penActive) {
+                       printf("W %d ", counter);
+               }
+               penActive = 0;
+               counter = 0;
+               printf(" CR\n");
+       }
+}