10 /* APPROX. 170 FPS Minimum */
12 #define BG_FILENAME "data/grise.png"
13 #define GROBJ_01_FILENAME "data/grobj_01.png"
15 #define BB_SIZE 512 /* Let's use a power of 2. Maybe we'll zoom/rotate the effect */
17 /* Every backBuffer scanline is guaranteed to have that many dummy pixels before and after */
18 #define PIXEL_PADDING 32
20 #define MIN_SCROLL PIXEL_PADDING
21 #define MAX_SCROLL (backgroundW - fb_width - MIN_SCROLL)
23 #define FAR_SCROLL_SPEED 50.0f
24 #define NEAR_SCROLL_SPEED 400.0f
26 #define HORIZON_HEIGHT 100
27 #define REFLECTION_HEIGHT (240 - HORIZON_HEIGHT)
29 #define NORMALMAP_SCANLINE 372
31 static int init(void);
32 static void destroy(void);
33 static void start(long trans_time);
34 /*static void stop(long trans_time);*/
35 static void draw(void);
37 static void convert32To16(unsigned int *src32, unsigned short *dst16, unsigned int pixelCount);
38 static void processNormal();
39 static void initScrollTables();
40 static void updateScrollTables(float dt);
42 static void rleEncode(unsigned char *pixels, unsigned int w, unsigned int h);
44 static unsigned short *background = 0;
45 static unsigned int backgroundW = 0;
46 static unsigned int backgroundH = 0;
48 static unsigned int lastFrameTime = 0;
49 static float lastFrameDuration = 0.0f;
51 static short *displacementMap;
53 static unsigned short *backBuffer;
55 static float scrollScaleTable[REFLECTION_HEIGHT];
56 static float scrollTable[REFLECTION_HEIGHT];
57 static int scrollTableRounded[REFLECTION_HEIGHT];
58 static int scrollModTable[REFLECTION_HEIGHT];
59 static float nearScrollAmount = 0.0f;
61 static struct screen scr = {
70 struct screen *grise_screen(void)
78 unsigned char *reflectedObject;
79 int reflectedObjectW, reflectedObjectH;
81 /* Allocate back buffer */
82 backBuffer = (unsigned short*) malloc(BB_SIZE * BB_SIZE * sizeof(unsigned short));
84 /* grise.png contains the background (horizon), baked reflection and normalmap for displacement */
85 if (!(background = img_load_pixels(BG_FILENAME, &backgroundW, &backgroundH, IMG_FMT_RGBA32))) {
86 fprintf(stderr, "failed to load image " BG_FILENAME "\n");
90 /* Convert to 16bpp */
91 convert32To16((unsigned int*)background, background, backgroundW * NORMALMAP_SCANLINE); /* Normalmap will keep its 32 bit color */
93 /* Load reflected objects */
94 if (!(reflectedObject = img_load_pixels(GROBJ_01_FILENAME, &reflectedObjectW, &reflectedObjectH, IMG_FMT_GREY8))) {
95 fprintf(stderr, "failed to load image " GROBJ_01_FILENAME "\n");
99 rleEncode(reflectedObject, reflectedObjectW, reflectedObjectH);
101 img_free_pixels(reflectedObject);
114 static void destroy(void)
119 img_free_pixels(background);
122 static void start(long trans_time)
124 lastFrameTime = time_msec;
127 /* XXX add the stop function when you have an out-transition, otherwise
128 * it just delays the change to the next effect.
131 static void stop(long trans_time)
136 static void draw(void)
138 int scroll = MIN_SCROLL + (MAX_SCROLL - MIN_SCROLL) * mouse_x / fb_width;
139 unsigned short *dst = backBuffer + PIXEL_PADDING;
140 unsigned short *src = background + scroll;
146 lastFrameDuration = (time_msec - lastFrameTime) / 1000.0f;
147 lastFrameTime = time_msec;
149 /* First, render the horizon */
150 for (scanline = 0; scanline < HORIZON_HEIGHT; scanline++) {
151 memcpy(dst, src, fb_width * 2);
156 /* Create scroll opffsets for all scanlines of the normalmap */
157 updateScrollTables(lastFrameDuration);
159 /* Then, render the reflection under the horizon */
160 /* dst is already in place */
161 src = background + HORIZON_HEIGHT * backgroundW;
162 dispScanline = displacementMap;
163 for (scanline = 0; scanline < REFLECTION_HEIGHT; scanline++) {
164 for (i = 0; i < fb_width; i++) {
165 d = dispScanline[(i + scrollTableRounded[scanline]) % scrollModTable[scanline]];
166 *dst++ = src[i + scroll + d];
169 dst += BB_SIZE - fb_width;
170 dispScanline += backgroundW;
173 /* Blit effect to framebuffer */
174 src = backBuffer + PIXEL_PADDING;
176 for (scanline = 0; scanline < fb_height; scanline++) {
177 memcpy(dst, src, fb_width * 2);
183 /* src and dst can be the same */
184 static void convert32To16(unsigned int *src32, unsigned short *dst16, unsigned int pixelCount) {
188 *dst16++ = ((p << 8) & 0xF800) /* R */
189 | ((p >> 5) & 0x07E0) /* G */
190 | ((p >> 19) & 0x001F); /* B */
195 /* Normal map preprocessing */
196 /* Scale normal with depth and unpack R component (horizontal component) */
197 static void processNormal() {
201 short maxDisplacement = 0;
202 short minDisplacement = 256;
205 unsigned int *normalmap = (unsigned int*)background;
206 normalmap += NORMALMAP_SCANLINE * backgroundW;
207 dst = (unsigned short*)normalmap;
208 displacementMap = (short*)dst;
209 dst2 = displacementMap;
211 for (scanline = 0; scanline < REFLECTION_HEIGHT; scanline++) {
212 scrollModTable[scanline] = (int) (backgroundW / scrollScaleTable[scanline] + 0.5f);
213 for (i = 0; i < backgroundW; i++) {
214 x = (int)(i * scrollScaleTable[scanline] + 0.5f);
215 if (x < backgroundW) {
216 *dst = (unsigned short)(normalmap[x] >> 8) & 0xFF;
217 if ((short)*dst > maxDisplacement) maxDisplacement = (short)(*dst);
218 if ((short)*dst < minDisplacement) minDisplacement = (short)(*dst);
224 normalmap += backgroundW;
227 if (maxDisplacement == minDisplacement) {
228 printf("Warning: grise normalmap fucked up\n");
232 /* Second pass - subtract half maximum displacement to displace in both directions */
233 for (scanline = 0; scanline < REFLECTION_HEIGHT; scanline++) {
234 for (i = 0; i < backgroundW; i++) {
235 /* Remember that MIN_SCROLL is the padding around the screen, so ti's the maximum displacement we can get (positive & negative) */
236 *dst2 = 2 * MIN_SCROLL * (*dst2 - minDisplacement) / (maxDisplacement - minDisplacement) - MIN_SCROLL;
237 *dst2 = (short)((float)*dst2 / scrollScaleTable[scanline] + 0.5f); /* Displacements must also scale with distance*/
243 static float distanceScale(int scanline) {
245 farScale = (float)NEAR_SCROLL_SPEED / (float)FAR_SCROLL_SPEED;
246 t = (float)scanline / ((float)REFLECTION_HEIGHT - 1);
247 return 1.0f / (1.0f / farScale + (1.0f - 1.0f / farScale) * t);
250 static void initScrollTables() {
252 for (i = 0; i < REFLECTION_HEIGHT; i++) {
253 scrollScaleTable[i] = distanceScale(i);
254 scrollTable[i] = 0.0f;
255 scrollTableRounded[i] = 0;
260 static void updateScrollTables(float dt) {
263 nearScrollAmount += dt * NEAR_SCROLL_SPEED;
264 nearScrollAmount = (float) fmod(nearScrollAmount, 512.0f);
266 for (i = 0; i < REFLECTION_HEIGHT; i++) {
267 scrollTable[i] = nearScrollAmount / scrollScaleTable[i];
268 scrollTableRounded[i] = (int)(scrollTable[i] + 0.5f) % scrollModTable[i];
272 static void rleEncode(unsigned char *pixels, unsigned int w, unsigned int h) {
277 for (scanline = 0; scanline < h; scanline++) {
278 for (i = 0; i < w; i++) {