1 // SPDX-License-Identifier: Apache-2.0
2 // ----------------------------------------------------------------------------
3 // Copyright 2011-2022 Arm Limited
4 //
5 // Licensed under the Apache License, Version 2.0 (the "License"); you may not
6 // use this file except in compliance with the License. You may obtain a copy
7 // of the License at:
8 //
9 // http://www.apache.org/licenses/LICENSE-2.0
10 //
11 // Unless required by applicable law or agreed to in writing, software
12 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
13 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
14 // License for the specific language governing permissions and limitations
15 // under the License.
16 // ----------------------------------------------------------------------------
17
18 /**
19 * @brief Functions for building the implementation of stb_image and tinyexr.
20 */
21
22 #include <cstdlib>
23 #include <cstdio>
24 #include <fstream>
25 #include <vector>
26
27 #include "astcenccli_internal.h"
28
29 // Configure the STB image imagewrite library build.
30 #define STB_IMAGE_IMPLEMENTATION
31 #define STB_IMAGE_WRITE_IMPLEMENTATION
32 #define STBI_NO_GIF
33 #define STBI_NO_PIC
34 #define STBI_NO_PNM
35 #define STBI_NO_PNG
36 #define STBI_NO_PSD
37
38 // Configure the TinyEXR library build.
39 #define TINYEXR_IMPLEMENTATION
40
41 // Configure the Wuffs library build.
42 #define WUFFS_IMPLEMENTATION
43 #define WUFFS_CONFIG__MODULES
44 #define WUFFS_CONFIG__MODULE__ADLER32
45 #define WUFFS_CONFIG__MODULE__BASE
46 #define WUFFS_CONFIG__MODULE__CRC32
47 #define WUFFS_CONFIG__MODULE__DEFLATE
48 #define WUFFS_CONFIG__MODULE__PNG
49 #define WUFFS_CONFIG__MODULE__ZLIB
50 #include "wuffs-v0.3.c"
51
52 // For both libraries force asserts (which can be triggered by corrupt input
53 // images) to be handled at runtime in release builds to avoid security issues.
54 #define STBI_ASSERT(x) astcenc_runtime_assert(x)
55 #define TEXR_ASSERT(x) astcenc_runtime_assert(x)
56
57 /**
58 * @brief Trap image load failures and convert into a runtime error.
59 */
astcenc_runtime_assert(bool condition)60 static void astcenc_runtime_assert(bool condition)
61 {
62 if (!condition)
63 {
64 printf("ERROR: Corrupt input image\n");
65 exit(1);
66 }
67 }
68
69 #include "stb_image.h"
70 #include "stb_image_write.h"
71 #include "tinyexr.h"
72
73 /**
74 * @brief Load an image using Wuffs to provide the loader.
75 *
76 * @param filename The name of the file to load.
77 * @param y_flip Should the image be vertically flipped?
78 * @param[out] is_hdr Is this an HDR image load?
79 * @param[out] component_count The number of components in the data.
80 *
81 * @return The loaded image data in a canonical 4 channel format, or @c nullptr on error.
82 */
load_png_with_wuffs(const char * filename,bool y_flip,bool & is_hdr,unsigned int & component_count)83 astcenc_image* load_png_with_wuffs(
84 const char* filename,
85 bool y_flip,
86 bool& is_hdr,
87 unsigned int& component_count
88 ) {
89 is_hdr = false;
90 component_count = 4;
91
92 std::ifstream file(filename, std::ios::binary | std::ios::ate);
93 if (!file)
94 {
95 printf("ERROR: Failed to load image %s (can't fopen)\n", filename);
96 return nullptr;
97 }
98
99 std::streamsize size = file.tellg();
100 file.seekg(0, std::ios::beg);
101
102 std::vector<uint8_t> buffer(size);
103 file.read((char*)buffer.data(), size);
104
105 wuffs_png__decoder *dec = wuffs_png__decoder__alloc();
106 if (!dec)
107 {
108 return nullptr;
109 }
110
111 wuffs_base__image_config ic;
112 wuffs_base__io_buffer src = wuffs_base__ptr_u8__reader(buffer.data(), size, true);
113 wuffs_base__status status = wuffs_png__decoder__decode_image_config(dec, &ic, &src);
114 if (status.repr)
115 {
116 return nullptr;
117 }
118
119 uint32_t dim_x = wuffs_base__pixel_config__width(&ic.pixcfg);
120 uint32_t dim_y = wuffs_base__pixel_config__height(&ic.pixcfg);
121 size_t num_pixels = dim_x * dim_y;
122 if (num_pixels > (SIZE_MAX / 4))
123 {
124 return nullptr;
125 }
126
127 // Override the image's native pixel format to be RGBA_NONPREMUL
128 wuffs_base__pixel_config__set(
129 &ic.pixcfg,
130 WUFFS_BASE__PIXEL_FORMAT__RGBA_NONPREMUL,
131 WUFFS_BASE__PIXEL_SUBSAMPLING__NONE,
132 dim_x, dim_y);
133
134 // Configure the work buffer
135 size_t workbuf_len = wuffs_png__decoder__workbuf_len(dec).max_incl;
136 if (workbuf_len > SIZE_MAX)
137 {
138 return nullptr;
139 }
140
141 wuffs_base__slice_u8 workbuf_slice = wuffs_base__make_slice_u8((uint8_t*)malloc(workbuf_len), workbuf_len);
142 if (!workbuf_slice.ptr)
143 {
144 return nullptr;
145 }
146
147 wuffs_base__slice_u8 pixbuf_slice = wuffs_base__make_slice_u8((uint8_t*)malloc(num_pixels * 4), num_pixels * 4);
148 if (!pixbuf_slice.ptr)
149 {
150 return nullptr;
151 }
152
153 wuffs_base__pixel_buffer pb;
154 status = wuffs_base__pixel_buffer__set_from_slice(&pb, &ic.pixcfg, pixbuf_slice);
155 if (status.repr)
156 {
157 return nullptr;
158 }
159
160 // Decode the pixels
161 status = wuffs_png__decoder__decode_frame(dec, &pb, &src, WUFFS_BASE__PIXEL_BLEND__SRC, workbuf_slice, NULL);
162 if (status.repr)
163 {
164 return nullptr;
165 }
166
167 astcenc_image* img = astc_img_from_unorm8x4_array(pixbuf_slice.ptr, dim_x, dim_y, y_flip);
168
169 free(pixbuf_slice.ptr);
170 free(workbuf_slice.ptr);
171 free(dec);
172
173 return img;
174 }
175