Fix Windows CI test run: 0xc0000135 (missing libpng16-16.dll on PATH) (issue 7)

.github/workflows/ci.yml

@@ -82,6 +82,15 @@ jobs:
           msystem: MINGW64
           install: mingw-w64-x86_64-libpng
 
+      # setup-msys2 only adds the MSYS2 root to the Windows PATH, so the test
+      # executable would not find libpng16-16.dll (and libz-1.dll) at runtime and
+      # fails with 0xc0000135 (STATUS_DLL_NOT_FOUND). Add the mingw64 bin
+      # directory to the PATH for the build/test steps.
+      - name: Add MSYS2 mingw64 bin to PATH (Windows)
+        if: runner.os == 'Windows'
+        run: |
+          Add-Content "$env:GITHUB_PATH" "${{ steps.msys2.outputs.msys2-location }}/mingw64/bin"
+
       - name: Configure CMake (Windows)
         if: runner.os == 'Windows'
         run: >

tests/test_OpenSimplex2F.c

@@ -4,6 +4,7 @@
 #endif
 #include <string.h>
 #include <errno.h>
+#include <sys/stat.h>
 
 #include <png.h>
 
@@ -68,17 +69,94 @@ static int write_png_image(const char *filename, unsigned char *pixels, int w, i
 	return rc;
 }
 
+/* ---------------------------------------------------------------------------
+ * Readable test output: every generated image is checked (noise value range
+ * and PNG file) and reported line by line, so the CI log shows what the
+ * test did and why it passed or failed.
+ * ------------------------------------------------------------------------- */
+
+struct noise_stats {
+	double min;
+	double max;
+	double sum;
+};
+
+static void stats_init(struct noise_stats *s)
+{
+	s->min = 1e300;
+	s->max = -1e300;
+	s->sum = 0.0;
+}
+
+static void stats_add(struct noise_stats *s, double value)
+{
+	if (value < s->min)
+		s->min = value;
+	if (value > s->max)
+		s->max = value;
+	s->sum += value;
+}
+
+/* All OpenSimplex2F variants are defined to return values in [-1, 1].
+ * The 3-octave blend of the 2D image is a convex combination of the same
+ * functions, so it stays in the same range. A small tolerance covers
+ * floating point rounding. */
+#define NOISE_LIMIT 1.0
+#define NOISE_EPSILON 1e-6
+
+static int report_test(int index, int total, const char *name, const char *png,
+		       int write_rc, const struct noise_stats *s)
+{
+	struct stat file;
+	long long size = 0;
+	double mean = s->sum / (double) (WIDTH * HEIGHT);
+	int in_range = (s->min >= -NOISE_LIMIT - NOISE_EPSILON) &&
+		       (s->max <= NOISE_LIMIT + NOISE_EPSILON);
+	int wrote = (write_rc == 0) && (stat(png, &file) == 0);
+	int ok = in_range && wrote;
+
+	if (wrote)
+		size = (long long) file.st_size;
+	printf("  [%d/%d] %-32s min=% .6f max=% .6f mean=% .6f -> %s (%lld bytes) ... %s\n",
+	       index, total, name, s->min, s->max, mean, png, size,
+	       ok ? "PASS" : "FAIL");
+	if (!in_range)
+		printf("       noise value outside the expected range [-1, 1]\n");
+	if (write_rc != 0)
+		printf("       write_png_image(%s) failed\n", png);
+	else if (!wrote)
+		printf("       %s is missing or unreadable\n", png);
+	return ok;
+}
+
 int main(__attribute__((unused)) int argc, __attribute__((unused)) char *argv[])
 {
 	int x, y;
 	double value;
 	double v0, v1, v2; /* values from different octaves. */
 	uint32_t rgb;
-	uint32_t image2d[HEIGHT][WIDTH];
-	uint32_t image3d[HEIGHT][WIDTH];
-	uint32_t image4d[HEIGHT][WIDTH];
+	int passed = 0;
+	/* Static storage: 3 x 1MB arrays would not fit the default Windows
+	 * thread stack (1MB) and crash with STATUS_STACK_BUFFER_OVERRUN
+	 * (0xC000013D); Linux survives them only because its default stack
+	 * is 8MB.
+	 */
+	static uint32_t image2d[HEIGHT][WIDTH];
+	static uint32_t image3d[HEIGHT][WIDTH];
+	static uint32_t image4d[HEIGHT][WIDTH];
 	struct OpenSimplex2F_context *ctx;
+	struct noise_stats st2d, st3d, st4d;
+#if defined(SINGLE_OCTAVE)
+	static const char *name2d = "open_simplex_noise4 (1 octave)";
+#else
+	static const char *name2d = "open_simplex_noise4 (3 octaves)";
+#endif
+
+	stats_init(&st2d);
+	stats_init(&st3d);
+	stats_init(&st4d);
 
+	printf("OpenSimplex2F tests (seed 77374, image %dx%d)\n", WIDTH, HEIGHT);
 	OpenSimplex2F(77374, &ctx);
 
 	for (y = 0; y < HEIGHT; y++) {
@@ -95,23 +173,36 @@ int main(__attribute__((unused)) int argc, __attribute__((unused)) char *argv[])
 						(double) y / FEATURE_SIZE / 1, 0.0, 0.0);
 			value = v0 * 4 / 7.0 + v1 * 2 / 7.0 + v2 * 1 / 7.0;
 #endif
+			stats_add(&st2d, value);
 			rgb = 0x010101 * (uint32_t) ((value + 1) * 127.5);
 			image2d[y][x] = ((uint32_t) 0x0ff << 24) | (rgb);
 
 			value = OpenSimplex2F_noise2(ctx, (double) x / FEATURE_SIZE, (double) y / FEATURE_SIZE);
+			stats_add(&st3d, value);
 			rgb = 0x010101 * (uint32_t) ((value + 1) * 127.5);
 			image3d[y][x] = ((uint32_t) 0x0ff << 24) | (rgb);
 
 			value = OpenSimplex2F_noise3_Classic(ctx, (double) x / FEATURE_SIZE, (double) y / FEATURE_SIZE, 0.0);
+			stats_add(&st4d, value);
 			rgb = 0x010101 * (uint32_t) ((value + 1) * 127.5);
 			image4d[y][x] = ((uint32_t) 0x0ff << 24) | (rgb);
 		}
 	}
-	write_png_image("test2d.png", (unsigned char *) image2d, WIDTH, HEIGHT, 1);
-	write_png_image("test3d.png", (unsigned char *) image3d, WIDTH, HEIGHT, 1);
-	write_png_image("test4d.png", (unsigned char *) image4d, WIDTH, HEIGHT, 1);
+	if (report_test(1, 3, name2d, "test2d.png",
+			write_png_image("test2d.png", (unsigned char *) image2d, WIDTH, HEIGHT, 1),
+			&st2d))
+		passed++;
+	if (report_test(2, 3, "OpenSimplex2F_noise2", "test3d.png",
+			write_png_image("test3d.png", (unsigned char *) image3d, WIDTH, HEIGHT, 1),
+			&st3d))
+		passed++;
+	if (report_test(3, 3, "OpenSimplex2F_noise3_Classic", "test4d.png",
+			write_png_image("test4d.png", (unsigned char *) image4d, WIDTH, HEIGHT, 1),
+			&st4d))
+		passed++;
 	OpenSimplex2F_free(ctx);
 	OpenSimplex2F_shutdown();
-	return 0;
+	printf("Result: %d/3 tests passed\n", passed);
+	return (passed == 3) ? 0 : 1;
 }