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      1 /*
      2  * Copyright (C) 2007 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include <stdlib.h>
     18 #include <unistd.h>
     19 
     20 #include <fcntl.h>
     21 #include <stdio.h>
     22 
     23 #include <sys/ioctl.h>
     24 #include <sys/mman.h>
     25 #include <sys/types.h>
     26 
     27 #include <linux/fb.h>
     28 #include <linux/kd.h>
     29 
     30 #include <pixelflinger/pixelflinger.h>
     31 
     32 #include <png.h>
     33 
     34 #include "minui.h"
     35 
     36 // libpng gives "undefined reference to 'pow'" errors, and I have no
     37 // idea how to convince the build system to link with -lm.  We don't
     38 // need this functionality (it's used for gamma adjustment) so provide
     39 // a dummy implementation to satisfy the linker.
     40 double pow(double x, double y) {
     41     return x;
     42 }
     43 
     44 int res_create_surface(const char* name, gr_surface* pSurface) {
     45     char resPath[256];
     46     GGLSurface* surface = NULL;
     47     int result = 0;
     48     unsigned char header[8];
     49     png_structp png_ptr = NULL;
     50     png_infop info_ptr = NULL;
     51 
     52     *pSurface = NULL;
     53 
     54     snprintf(resPath, sizeof(resPath)-1, "/res/images/%s.png", name);
     55     resPath[sizeof(resPath)-1] = '\0';
     56     FILE* fp = fopen(resPath, "rb");
     57     if (fp == NULL) {
     58         result = -1;
     59         goto exit;
     60     }
     61 
     62     size_t bytesRead = fread(header, 1, sizeof(header), fp);
     63     if (bytesRead != sizeof(header)) {
     64         result = -2;
     65         goto exit;
     66     }
     67 
     68     if (png_sig_cmp(header, 0, sizeof(header))) {
     69         result = -3;
     70         goto exit;
     71     }
     72 
     73     png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
     74     if (!png_ptr) {
     75         result = -4;
     76         goto exit;
     77     }
     78 
     79     info_ptr = png_create_info_struct(png_ptr);
     80     if (!info_ptr) {
     81         result = -5;
     82         goto exit;
     83     }
     84 
     85     if (setjmp(png_jmpbuf(png_ptr))) {
     86         result = -6;
     87         goto exit;
     88     }
     89 
     90     png_init_io(png_ptr, fp);
     91     png_set_sig_bytes(png_ptr, sizeof(header));
     92     png_read_info(png_ptr, info_ptr);
     93 
     94     size_t width = info_ptr->width;
     95     size_t height = info_ptr->height;
     96     size_t stride = 4 * width;
     97     size_t pixelSize = stride * height;
     98 
     99     int color_type = info_ptr->color_type;
    100     int bit_depth = info_ptr->bit_depth;
    101     int channels = info_ptr->channels;
    102     if (!(bit_depth == 8 &&
    103           ((channels == 3 && color_type == PNG_COLOR_TYPE_RGB) ||
    104            (channels == 4 && color_type == PNG_COLOR_TYPE_RGBA) ||
    105            (channels == 1 && color_type == PNG_COLOR_TYPE_PALETTE)))) {
    106         return -7;
    107         goto exit;
    108     }
    109 
    110     surface = malloc(sizeof(GGLSurface) + pixelSize);
    111     if (surface == NULL) {
    112         result = -8;
    113         goto exit;
    114     }
    115     unsigned char* pData = (unsigned char*) (surface + 1);
    116     surface->version = sizeof(GGLSurface);
    117     surface->width = width;
    118     surface->height = height;
    119     surface->stride = width; /* Yes, pixels, not bytes */
    120     surface->data = pData;
    121     surface->format = (channels == 3) ?
    122             GGL_PIXEL_FORMAT_RGBX_8888 : GGL_PIXEL_FORMAT_RGBA_8888;
    123 
    124     int alpha = 0;
    125     if (color_type == PNG_COLOR_TYPE_PALETTE) {
    126         png_set_palette_to_rgb(png_ptr);
    127     }
    128     if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) {
    129         png_set_tRNS_to_alpha(png_ptr);
    130         alpha = 1;
    131     }
    132 
    133     int y;
    134     if (channels == 3 || (channels == 1 && !alpha)) {
    135         for (y = 0; y < height; ++y) {
    136             unsigned char* pRow = pData + y * stride;
    137             png_read_row(png_ptr, pRow, NULL);
    138 
    139             int x;
    140             for(x = width - 1; x >= 0; x--) {
    141                 int sx = x * 3;
    142                 int dx = x * 4;
    143                 unsigned char r = pRow[sx];
    144                 unsigned char g = pRow[sx + 1];
    145                 unsigned char b = pRow[sx + 2];
    146                 unsigned char a = 0xff;
    147                 pRow[dx    ] = r; // r
    148                 pRow[dx + 1] = g; // g
    149                 pRow[dx + 2] = b; // b
    150                 pRow[dx + 3] = a;
    151             }
    152         }
    153     } else {
    154         for (y = 0; y < height; ++y) {
    155             unsigned char* pRow = pData + y * stride;
    156             png_read_row(png_ptr, pRow, NULL);
    157         }
    158     }
    159 
    160     *pSurface = (gr_surface) surface;
    161 
    162 exit:
    163     png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
    164 
    165     if (fp != NULL) {
    166         fclose(fp);
    167     }
    168     if (result < 0) {
    169         if (surface) {
    170             free(surface);
    171         }
    172     }
    173     return result;
    174 }
    175 
    176 void res_free_surface(gr_surface surface) {
    177     GGLSurface* pSurface = (GGLSurface*) surface;
    178     if (pSurface) {
    179         free(pSurface);
    180     }
    181 }
    182