Various reflection improvements

diff --git a/src/mike.c b/src/mike.c
index 850c09a..333a4aa 100644 (file)
--- a/src/mike.c
+++ b/src/mike.c
@@ -7,6 +7,8 @@
 #include "demo.h"
 #include "screen.h"
 
+/* APPROX. 170 FPS Minimum */
+
 #define BG_FILENAME "data/grise.png"
 
 #define MIN_SCROLL 32
@@ -40,10 +42,11 @@ static float lastFrameDuration = 0.0f;
 
 static short *displacementMap;
 
-static float scrollSpeedTable[REFLECTION_HEIGHT];
+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 struct screen scr = {
        "mike",
@@ -70,10 +73,10 @@ static int init(void)
        /* Convert to 16bpp */
        convert32To16((unsigned int*)background, background, backgroundW * NORMALMAP_SCANLINE); /* Normalmap will keep its 32 bit color */
 
-       processNormal();
-
        initScrollTables();
 
+       processNormal();
+
        return 0;
 }
 
@@ -141,7 +144,6 @@ static void convert32To16(unsigned int *src32, unsigned short *dst16, unsigned i
 /* Scale normal with depth and unpack R component (horizontal component) */
 static void processNormal() {
        int scanline;
-       float scale;
        int i;
        int x;
        short maxDisplacement = 0;
@@ -155,12 +157,11 @@ static void processNormal() {
        dst2 = displacementMap;
 
        for (scanline = 0; scanline < REFLECTION_HEIGHT; scanline++) {
-               scale = 2.0f - (float)scanline / ((float)REFLECTION_HEIGHT - 1);
-               scrollModTable[scanline] = (int) (backgroundW / scale + 0.5f);
+               scrollModTable[scanline] = (int) (backgroundW / scrollScaleTable[scanline] + 0.5f);
                for (i = 0; i < backgroundW; i++) {
-                       x = (int)(i * scale + 0.5f);
+                       x = (int)(i * scrollScaleTable[scanline] + 0.5f);
                        if (x < backgroundW) {
-                               *dst = (unsigned short)normalmap[x] & 0xFF;
+                               *dst = (unsigned short)(normalmap[x] >> 8) & 0xFF;
                                if ((short)*dst > maxDisplacement) maxDisplacement = (short)(*dst);
                                if ((short)*dst < minDisplacement) minDisplacement = (short)(*dst);
                        } else {
@@ -181,18 +182,23 @@ static void processNormal() {
                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 = (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;
-       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;
+               scrollScaleTable[i] = distanceScale(i);
                scrollTable[i] = 0.0f;
                scrollTableRounded[i] = 0;
        }
@@ -201,8 +207,12 @@ static void initScrollTables() {
 
 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] += scrollSpeedTable[i] * dt;
+               scrollTable[i] = nearScrollAmount / scrollScaleTable[i];
                scrollTableRounded[i] = (int)(scrollTable[i] + 0.5f) % scrollModTable[i];
        }
 }