+libspng

projects/libspng.org/example.c

@@ -0,0 +1,124 @@
+#include <spng.h>
+
+#include <inttypes.h>
+#include <stdio.h>
+
+int main(int argc, char **argv)
+{
+    int r = 0;
+    FILE *png;
+    char *pngbuf = NULL;
+    spng_ctx *ctx = NULL;
+    unsigned char *out = NULL;
+
+    if(argc < 2)
+    {
+        printf("no input file\n");
+        goto err;
+    }
+
+    png = fopen(argv[1], "rb");
+    if(png == NULL)
+    {
+        printf("error opening input file %s\n", argv[1]);
+        goto err;
+    }
+
+    fseek(png, 0, SEEK_END);
+
+    long siz_pngbuf = ftell(png);
+    rewind(png);
+
+    if(siz_pngbuf < 1) goto err;
+
+    pngbuf = malloc(siz_pngbuf);
+    if(pngbuf == NULL)
+    {
+        printf("malloc() failed\n");
+        goto err;
+    }
+
+    if(fread(pngbuf, siz_pngbuf, 1, png) != 1)
+    {
+        printf("fread() failed\n");
+        goto err;
+    }
+
+    ctx = spng_ctx_new(0);
+    if(ctx == NULL)
+    {
+        printf("spng_ctx_new() failed\n");
+        goto err;
+    }
+
+    r = spng_set_crc_action(ctx, SPNG_CRC_USE, SPNG_CRC_USE);
+
+    if(r)
+    {
+        printf("spng_set_crc_action() error: %s\n", spng_strerror(r));
+        goto err;
+    }
+
+    r = spng_set_png_buffer(ctx, pngbuf, siz_pngbuf);
+
+    if(r)
+    {
+        printf("spng_set_png_buffer() error: %s\n", spng_strerror(r));
+        goto err;
+    }
+
+    struct spng_ihdr ihdr;
+    r = spng_get_ihdr(ctx, &ihdr);
+
+    if(r)
+    {
+        printf("spng_get_ihdr() error: %s\n", spng_strerror(r));
+        goto err;
+    }
+
+    char *clr_type_str;
+    if(ihdr.color_type == SPNG_COLOR_TYPE_GRAYSCALE)
+        clr_type_str = "grayscale";
+    else if(ihdr.color_type == SPNG_COLOR_TYPE_TRUECOLOR)
+        clr_type_str = "truecolor";
+    else if(ihdr.color_type == SPNG_COLOR_TYPE_INDEXED)
+        clr_type_str = "indexed color";
+    else if(ihdr.color_type == SPNG_COLOR_TYPE_GRAYSCALE_ALPHA)
+        clr_type_str = "grayscale with alpha";
+    else
+        clr_type_str = "truecolor with alpha";
+
+    printf("width: %" PRIu32 "\nheight: %" PRIu32 "\n"
+           "bit depth: %" PRIu8 "\ncolor type: %" PRIu8 " - %s\n",
+           ihdr.width, ihdr.height,
+           ihdr.bit_depth, ihdr.color_type, clr_type_str);
+    printf("compression method: %" PRIu8 "\nfilter method: %" PRIu8 "\n"
+           "interlace method: %" PRIu8 "\n",
+           ihdr.compression_method, ihdr.filter_method,
+           ihdr.interlace_method);
+
+    size_t out_size;
+
+    r = spng_decoded_image_size(ctx, SPNG_FMT_RGBA8, &out_size);
+
+    if(r) goto err;
+
+    out = malloc(out_size);
+    if(out == NULL) goto err;
+
+    r = spng_decode_image(ctx, out, out_size, SPNG_FMT_RGBA8, 0);
+
+    if(r)
+    {
+        printf("spng_decode_image() error: %s\n", spng_strerror(r));
+        goto err;
+    }
+
+err:
+    spng_ctx_free(ctx);
+    
+    free(out);
+    free(pngbuf);
+
+    return r;
+}

projects/libspng.org/expected_output.txt

@@ -0,0 +1,7 @@
+width: 8
+height: 8
+bit depth: 1
+color type: 3 - indexed color
+compression method: 0
+filter method: 0
+interlace method: 0

projects/libspng.org/package.yml

@@ -0,0 +1,31 @@
+distributable:
+  url: https://github.com/randy408/libspng/archive/refs/tags/v{{version}}.tar.gz
+  strip-components: 1
+
+versions:
+  gitlab: randy408/libspng
+
+dependencies:
+  darwin:
+    zlib.net: '*'
+
+build:
+  dependencies:
+    tea.xyz/gx/cc: c99
+    ninja-build.org: 1
+    freedesktop.org/pkg-config: '*'
+    mesonbuild.com: '*'
+  working-directory: build
+  script: |
+    meson .. --prefix={{prefix}} --libdir={{prefix}}/lib --buildtype=release
+    ninja -v
+    ninja install -v
+
+test:
+  dependencies:
+    tea.xyz/gx/cc: c99
+  script: |
+    cc example.c -lspng -o example
+    actual_output="$(./example 'test.png')"
+    echo "$actual_output" > actual_output.txt
+    test "$(cat actual_output.txt)" = "$(cat expected_output.txt)"