Implement ctest unit test, first test simply testing that envelope works as it used to.

tests/test_renderer.c

@@ -0,0 +1,77 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+extern void __stdcall _4klang_render();
+extern int test_max_samples;
+extern char test_name[];
+
+int main(int argc, char* argv[]) {
+	FILE* f;
+	float* buf;
+	char filename[256];
+	int n;
+	float v;
+	int retval;
+
+	buf = (float*)malloc(test_max_samples * 2 * sizeof(float));
+
+	if (buf == NULL) {
+		printf("Could not allocate buffer\n");
+		return 1;
+	}
+
+	_4klang_render(buf);
+
+	snprintf(filename, sizeof filename, "%s%s", test_name, "_expected.raw");
+
+	f = fopen(filename, "rb");
+
+	if (f == NULL) {
+		printf("No expected waveform found!\n");
+		retval = 1;
+		goto end;
+	}
+
+	n = 0;
+	while (1) {		
+		fread((void*)(&v), sizeof(v), 1, f);		
+		if (feof(f)) {
+			if (n == test_max_samples * 2) {
+				retval = 0;
+			}
+			else {
+				printf("4klang rendered longer wave than expected\n");
+				retval = 1;
+			}
+			break;
+		}
+		if (n >= test_max_samples * 2) {
+			printf("4klang rendered shorter wave than expected\n");
+			retval = 1;
+			break;
+		}
+		if (buf[n] != v) {
+			printf("4klang rendered different wave than expected\n");
+			retval = 1;
+			break;
+		}
+		++n;		
+	}	
+end:
+
+	if (f != 0) {
+		fclose(f);
+		f = 0;
+	}	
+	
+	snprintf(filename, sizeof filename, "%s%s", test_name, "_got.raw");
+	f = fopen(filename, "wb");	
+	fwrite((void*)buf, sizeof(*buf), 2 * test_max_samples, f);
+	fclose(f);
+
+	if (buf != 0) {
+		free(buf);
+		buf = 0;
+	}
+	return retval;
+}