Applied displacement to reflection

[dosdemo] / src / mike.c

diff --git a/src/mike.c b/src/mike.c
index 719121e..4f92011 100644 (file)
--- a/src/mike.c
+++ b/src/mike.c
@@ -9,6 +9,17 @@
 
 #define BG_FILENAME "data/grise.png"
 
+#define MIN_SCROLL 32
+#define MAX_SCROLL (backgroundW - fb_width - MIN_SCROLL)
+
+#define FAR_SCROLL_SPEED 50.0f
+#define NEAR_SCROLL_SPEED 400.0f
+
+#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);
@@ -16,11 +27,24 @@ 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 unsigned int backgroundW = 0;
 static unsigned int backgroundH = 0;
 
+static unsigned int lastFrameTime = 0;
+static float lastFrameDuration = 0.0f;
+
+static short *displacementMap;
+
+static float scrollSpeedTable[REFLECTION_HEIGHT];
+static float scrollTable[REFLECTION_HEIGHT];
+static int scrollTableRounded[REFLECTION_HEIGHT];
+static int scrollModTable[REFLECTION_HEIGHT];
+
 static struct screen scr = {
        "mike",
        init,
@@ -44,19 +68,23 @@ static int init(void)
        }
 
        /* Convert to 16bpp */
-       convert32To16((unsigned int*)background, background, backgroundW * backgroundH);
+       convert32To16((unsigned int*)background, background, backgroundW * NORMALMAP_SCANLINE); /* Normalmap will keep its 32 bit color */
+
+       processNormal();
+
+       initScrollTables();
 
        return 0;
 }
 
 static void destroy(void)
 {
-       img_free_pixels(background);
+       //img_free_pixels(background);
 }
 
 static void start(long trans_time)
 {
-
+       lastFrameTime = time_msec;
 }
 
 static void stop(long trans_time)
@@ -65,16 +93,35 @@ static void stop(long trans_time)
 
 static void draw(void)
 {      
-       unsigned short *pixels = fb_pixels;
+       int scroll = MIN_SCROLL + (MAX_SCROLL - MIN_SCROLL) * mouse_x / fb_width;
+       unsigned short *dst = fb_pixels;
+       unsigned short *src = background + scroll;
+       int scanline = 0;
+       int i = 0;
+       short *disp;
+       int d;
+
+       lastFrameDuration = (time_msec - lastFrameTime) / 1000.0f;
+       lastFrameTime = time_msec;
+
+       for (scanline = 0; scanline < fb_height; scanline++) {
+               memcpy(dst, src, fb_width * 2);
+               src += backgroundW;
+               dst += fb_width;
+       }
+       
+       updateScrollTables(lastFrameDuration);
 
-       int j, i;
-       for (j = 0; j < fb_height; j++) {
+       dst = (unsigned short*) fb_pixels + HORIZON_HEIGHT * fb_width;
+       src = background + HORIZON_HEIGHT * backgroundW;
+       disp = displacementMap;
+       for (scanline = 0; scanline < REFLECTION_HEIGHT; scanline++) {
                for (i = 0; i < fb_width; i++) {
-                       *pixels++ = 0x0000;
+                       d = disp[(i + scrollTableRounded[scanline]) % scrollModTable[scanline]];
+                       *dst++ = src[i + scroll + d];
                }
+               src += backgroundW;
        }
-
-       memcpy(fb_pixels, background, backgroundW * backgroundH * 2);
 }
 
 /* src and dst can be the same */
@@ -89,4 +136,70 @@ static void convert32To16(unsigned int *src32, unsigned short *dst16, unsigned i
        }
 }
 
+/* Normal map preprocessing */
+/* Scale normal with depth and unpack R component (horizontal component) */
+static void processNormal() {
+       int scanline;
+       unsigned int *normalmap = (unsigned int*)background;
+       normalmap += NORMALMAP_SCANLINE * backgroundW;
+       unsigned short *dst = normalmap;
+       displacementMap = (short*)dst;
+       short *dst2 = displacementMap;
+       float scale;
+       int i;
+       int x;
+       short maxDisplacement = 0;
+       short minDisplacement = 256;
+
+       for (scanline = 0; scanline < REFLECTION_HEIGHT; scanline++) {
+               scale = 2.0f - (float)scanline / ((float)REFLECTION_HEIGHT - 1);
+               scrollModTable[scanline] = (int) (backgroundW / scale + 0.5f);
+               for (i = 0; i < backgroundW; i++) {
+                       x = (int)(i * scale + 0.5f);
+                       if (x < background) {
+                               *dst = (unsigned short)normalmap[x] & 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 * MIN_SCROLL * (*dst2 - minDisplacement) / (maxDisplacement - minDisplacement) - MIN_SCROLL;
+                       dst2++;
+               }
+       }
+}
+
+static void initScrollTables() {
+       int i = 0;
+       float scrollSpeed = FAR_SCROLL_SPEED;
+       float speedIncrement = (NEAR_SCROLL_SPEED - FAR_SCROLL_SPEED) / ((float) (REFLECTION_HEIGHT - 1));
+       for (i = 0; i < REFLECTION_HEIGHT; i++) {
+               scrollSpeedTable[i] = scrollSpeed;
+               scrollSpeed += speedIncrement;
+               scrollTable[i] = 0.0f;
+               scrollTableRounded[i] = 0;
+       }
+}
+
 
+static void updateScrollTables(float dt) {
+       int i = 0;
+       for (i = 0; i < REFLECTION_HEIGHT; i++) {
+               scrollTable[i] += scrollSpeedTable[i] * dt;
+               scrollTableRounded[i] = (int)(scrollTable[i] + 0.5f) % scrollModTable[i];
+       }
+}
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