Added normalmap + parallax scrolling

[dosdemo] / src / mike.c

diff --git a/src/mike.c b/src/mike.c
index f985886..411592a 100644 (file)
--- a/src/mike.c
+++ b/src/mike.c
@@ -7,12 +7,42 @@
 #include "demo.h"
 #include "screen.h"
 
+#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);
 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 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,
@@ -30,37 +60,116 @@ struct screen *mike_screen(void)
 
 static int init(void)
 {
+       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 */
+
+       processNormal();
+
+       initScrollTables();
+
        return 0;
 }
 
 static void destroy(void)
 {
+       //img_free_pixels(background);
 }
 
 static void start(long trans_time)
 {
-       if(trans_time) {
-               
-       }
+       lastFrameTime = time_msec;
 }
 
 static void stop(long trans_time)
 {
-       if(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;
+
+       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 = fb_pixels;
+       dst += 100 * fb_width;
+       src = background + NORMALMAP_SCANLINE * backgroundW * 2;
+       for (scanline = 0; scanline < REFLECTION_HEIGHT; scanline++) {
                for (i = 0; i < fb_width; i++) {
-                       *pixels++ = 0xF800;
+                       *dst++ = src[(i + scrollTableRounded[scanline]) % scrollModTable[scanline]];
+               }
+               src += backgroundW;
+       }
+}
+
+/* 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;
+       unsigned int *normalmap = (unsigned int*)background;
+       normalmap += NORMALMAP_SCANLINE * backgroundW;
+       unsigned short *dst = normalmap;
+       float scale;
+       int i;
+       int x;
+
+       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);
+                       *dst++ = x < backgroundW ? normalmap[x] & 0xFF : 0;
                }
+               normalmap += backgroundW;
        }
 }
 
+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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