+
+/*
+ * Routines to render the lzss image format
+ */
+
+struct lzss_image_state {
+ uint32_t col;
+ uint32_t row;
+ uint32_t width;
+ uint32_t height;
+ uint32_t bytes_per_row;
+ volatile uint32_t * row_start;
+ const uint8_t* clut;
+};
+typedef struct lzss_image_state lzss_image_state;
+
+// returns 0 if OK, 1 if error
+static inline int
+vc_decompress_lzss_next_pixel (int next_data, lzss_image_state* state)
+{
+ uint32_t palette_index = 0;
+ uint32_t pixel_value = 0;
+
+ palette_index = next_data * 3;
+
+ pixel_value = ( (uint32_t) state->clut[palette_index + 0] << 16)
+ | ( (uint32_t) state->clut[palette_index + 1] << 8)
+ | ( (uint32_t) state->clut[palette_index + 2]);
+
+ *(state->row_start + state->col) = pixel_value;
+
+ if (++state->col >= state->width) {
+ state->col = 0;
+ if (++state->row >= state->height) {
+ return 1;
+ }
+ state->row_start = (volatile uint32_t *) (((uintptr_t)state->row_start) + state->bytes_per_row);
+ }
+ return 0;
+}
+
+
+/*
+ * Blit an lzss compressed image to the framebuffer
+ * Assumes 32 bit screen (which is everything we ship at the moment)
+ * The function vc_display_lzss_icon was copied from libkern/mkext.c, then modified.
+ */
+
+/*
+ * TODO: Does lzss use too much stack? 4096 plus bytes...
+ * Can probably chop it down by 1/2.
+ */
+
+/**************************************************************
+ LZSS.C -- A Data Compression Program
+***************************************************************
+ 4/6/1989 Haruhiko Okumura
+ Use, distribute, and modify this program freely.
+ Please send me your improved versions.
+ PC-VAN SCIENCE
+ NIFTY-Serve PAF01022
+ CompuServe 74050,1022
+
+**************************************************************/
+
+#define N 4096 /* size of ring buffer - must be power of 2 */
+#define F 18 /* upper limit for match_length */
+#define THRESHOLD 2 /* encode string into position and length
+ if match_length is greater than this */
+
+// returns 0 if OK, 1 if error
+// x and y indicate upper left corner of image location on screen
+int
+vc_display_lzss_icon(uint32_t dst_x, uint32_t dst_y,
+ uint32_t image_width, uint32_t image_height,
+ const uint8_t *compressed_image,
+ uint32_t compressed_size,
+ const uint8_t *clut)
+{
+ uint32_t* image_start;
+ uint32_t bytes_per_pixel = 4;
+ uint32_t bytes_per_row = vinfo.v_rowbytes;
+
+ image_start = (uint32_t *) (vinfo.v_baseaddr + (dst_y * bytes_per_row) + (dst_x * bytes_per_pixel));
+
+ lzss_image_state state = {0, 0, image_width, image_height, bytes_per_row, image_start, clut};
+
+ int rval = 0;
+
+ const uint8_t *src = compressed_image;
+ uint32_t srclen = compressed_size;
+
+ /* ring buffer of size N, with extra F-1 bytes to aid string comparison */
+ uint8_t text_buf[N + F - 1];
+ const uint8_t *srcend = src + srclen;
+ int i, j, k, r, c;
+ unsigned int flags;
+
+ srcend = src + srclen;
+ for (i = 0; i < N - F; i++)
+ text_buf[i] = ' ';
+ r = N - F;
+ flags = 0;
+ for ( ; ; ) {
+ if (((flags >>= 1) & 0x100) == 0) {
+ if (src < srcend) c = *src++; else break;
+ flags = c | 0xFF00; /* uses higher byte cleverly */
+ } /* to count eight */
+ if (flags & 1) {
+ if (src < srcend) c = *src++; else break;
+ rval = vc_decompress_lzss_next_pixel(c, &state);
+ if (rval != 0)
+ return rval;
+ text_buf[r++] = c;
+ r &= (N - 1);
+ } else {
+ if (src < srcend) i = *src++; else break;
+ if (src < srcend) j = *src++; else break;
+ i |= ((j & 0xF0) << 4);
+ j = (j & 0x0F) + THRESHOLD;
+ for (k = 0; k <= j; k++) {
+ c = text_buf[(i + k) & (N - 1)];
+ rval = vc_decompress_lzss_next_pixel(c, &state);
+ if (rval != 0 )
+ return rval;
+ text_buf[r++] = c;
+ r &= (N - 1);
+ }
+ }
+ }
+ return 0;
+}
+
+void noroot_icon_test(void) {
+ boolean_t o_vc_progress_enable = vc_progress_enable;
+
+ vc_progress_enable = 1;
+
+ PE_display_icon( 0, "noroot");
+
+ vc_progress_enable = o_vc_progress_enable;
+}
+
+
projects / apple / xnu.git / commitdiff
