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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     snprintf(resPath, sizeof(resPath)-1, "/res/images/%s.png", name);
     53     resPath[sizeof(resPath)-1] = '\0';
     54     FILE* fp = fopen(resPath, "rb");
     55     if (fp == NULL) {
     56         result = -1;
     57         goto exit;
     58     }
     59 
     60     size_t bytesRead = fread(header, 1, sizeof(header), fp);
     61     if (bytesRead != sizeof(header)) {
     62         result = -2;
     63         goto exit;
     64     }
     65 
     66     if (png_sig_cmp(header, 0, sizeof(header))) {
     67         result = -3;
     68         goto exit;
     69     }
     70 
     71     png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
     72     if (!png_ptr) {
     73         result = -4;
     74         goto exit;
     75     }
     76 
     77     info_ptr = png_create_info_struct(png_ptr);
     78     if (!info_ptr) {
     79         result = -5;
     80         goto exit;
     81     }
     82 
     83     if (setjmp(png_jmpbuf(png_ptr))) {
     84         result = -6;
     85         goto exit;
     86     }
     87 
     88     png_init_io(png_ptr, fp);
     89     png_set_sig_bytes(png_ptr, sizeof(header));
     90     png_read_info(png_ptr, info_ptr);
     91 
     92     size_t width = info_ptr->width;
     93     size_t height = info_ptr->height;
     94     size_t stride = 4 * width;
     95     size_t pixelSize = stride * height;
     96 
     97     int color_type = info_ptr->color_type;
     98     int bit_depth = info_ptr->bit_depth;
     99     int channels = info_ptr->channels;
    100     if (!(bit_depth == 8 &&
    101           ((channels == 3 && color_type == PNG_COLOR_TYPE_RGB) ||
    102            (channels == 4 && color_type == PNG_COLOR_TYPE_RGBA) ||
    103            (channels == 1 && color_type == PNG_COLOR_TYPE_PALETTE)))) {
    104         return -7;
    105         goto exit;
    106     }
    107 
    108     surface = malloc(sizeof(GGLSurface) + pixelSize);
    109     if (surface == NULL) {
    110         result = -8;
    111         goto exit;
    112     }
    113     unsigned char* pData = (unsigned char*) (surface + 1);
    114     surface->version = sizeof(GGLSurface);
    115     surface->width = width;
    116     surface->height = height;
    117     surface->stride = width; /* Yes, pixels, not bytes */
    118     surface->data = pData;
    119     surface->format = (channels == 3) ?
    120             GGL_PIXEL_FORMAT_RGBX_8888 : GGL_PIXEL_FORMAT_RGBA_8888;
    121 
    122     if (color_type == PNG_COLOR_TYPE_PALETTE) {
    123       png_set_palette_to_rgb(png_ptr);
    124     }
    125 
    126     int y;
    127     if (channels == 3) {
    128         for (y = 0; y < height; ++y) {
    129             unsigned char* pRow = pData + y * stride;
    130             png_read_row(png_ptr, pRow, NULL);
    131 
    132             int x;
    133             for(x = width - 1; x >= 0; x--) {
    134                 int sx = x * 3;
    135                 int dx = x * 4;
    136                 unsigned char r = pRow[sx];
    137                 unsigned char g = pRow[sx + 1];
    138                 unsigned char b = pRow[sx + 2];
    139                 unsigned char a = 0xff;
    140                 pRow[dx    ] = r; // r
    141                 pRow[dx + 1] = g; // g
    142                 pRow[dx + 2] = b; // b
    143                 pRow[dx + 3] = a;
    144             }
    145         }
    146     } else {
    147         for (y = 0; y < height; ++y) {
    148             unsigned char* pRow = pData + y * stride;
    149             png_read_row(png_ptr, pRow, NULL);
    150         }
    151     }
    152 
    153     *pSurface = (gr_surface) surface;
    154 
    155 exit:
    156     png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
    157 
    158     if (fp != NULL) {
    159         fclose(fp);
    160     }
    161     if (result < 0) {
    162         if (surface) {
    163             free(surface);
    164         }
    165     }
    166     return result;
    167 }
    168 
    169 void res_free_surface(gr_surface surface) {
    170     GGLSurface* pSurface = (GGLSurface*) surface;
    171     if (pSurface) {
    172         free(pSurface);
    173     }
    174 }
    175