From 9b42315ef051745b94eeb31d4680f821779b50a2 Mon Sep 17 00:00:00 2001
From: sanine <sanine.not@pm.me>
Date: Tue, 27 Sep 2022 20:36:05 -0500
Subject: fix off-by-1 bug in face indexing
---
src/import/import.c | 11 +++++++++--
src/import/import_mesh.test.c | 17 +++++++++--------
src/main.c | 25 ++++++++++++++++++++++++-
3 files changed, 42 insertions(+), 11 deletions(-)
diff --git a/src/import/import.c b/src/import/import.c
index a093068..becb1fe 100644
--- a/src/import/import.c
+++ b/src/import/import.c
@@ -15,7 +15,10 @@ int import_file(lua_State *L)
char *filename;
hs_parse_args(L, hs_str(filename));
- const struct aiScene *scene = aiImportFile(filename, aiProcess_Triangulate | aiProcess_FlipUVs);
+ const struct aiScene *scene = aiImportFile(
+ filename,
+ aiProcess_Triangulate | aiProcess_FlipUVs
+ );
if (scene == NULL)
hs_throw_error(L, "failed to load file '%s'", filename);
@@ -53,7 +56,11 @@ static void push_face(lua_State *L, struct aiFace face)
for (int i=0; i<face.mNumIndices; i++) {
/* add one to the index bc lua is 1-indexed */
- lua_pushinteger(L, face.mIndices[i]+1);
+ /* the above comment is WRONG WRONG WRONG!!
+ * lua is indeed 1-indexed, but this data is being interpreted
+ * by *opengl* not lua. we should not add 1!!
+ */
+ lua_pushinteger(L, face.mIndices[i]);
lua_rawseti(L, tbl, i+1);
}
}
diff --git a/src/import/import_mesh.test.c b/src/import/import_mesh.test.c
index fdbfbf0..7dc8624 100644
--- a/src/import/import_mesh.test.c
+++ b/src/import/import_mesh.test.c
@@ -55,18 +55,19 @@ void test_push_face()
lily_assert_int_equal(lua_objlen(L, facetbl), 6);
/* the numbers should be one higher because of lua's 1-indexing */
+ /* WRONG! the numbers should be 0-indexed because they will be interpreted by opengl */
lua_rawgeti(L, facetbl, 1);
- lily_assert_int_equal(lua_tointeger(L, -1), 1);
+ lily_assert_int_equal(lua_tointeger(L, -1), 0);
lua_rawgeti(L, facetbl, 2);
- lily_assert_int_equal(lua_tointeger(L, -1), 2);
+ lily_assert_int_equal(lua_tointeger(L, -1), 1);
lua_rawgeti(L, facetbl, 3);
- lily_assert_int_equal(lua_tointeger(L, -1), 3);
+ lily_assert_int_equal(lua_tointeger(L, -1), 2);
lua_rawgeti(L, facetbl, 4);
- lily_assert_int_equal(lua_tointeger(L, -1), 4);
+ lily_assert_int_equal(lua_tointeger(L, -1), 3);
lua_rawgeti(L, facetbl, 5);
- lily_assert_int_equal(lua_tointeger(L, -1), 5);
+ lily_assert_int_equal(lua_tointeger(L, -1), 4);
lua_rawgeti(L, facetbl, 6);
- lily_assert_int_equal(lua_tointeger(L, -1), 6);
+ lily_assert_int_equal(lua_tointeger(L, -1), 5);
lua_close(L);
}
@@ -414,8 +415,8 @@ static int check_face(lua_State *L, int meshtbl, const char *field, int index,
void test_faces(lua_State *L, int meshtbl)
{
- check_face(L, meshtbl, "faces", 1, 1, 2, 4);
- check_face(L, meshtbl, "faces", 2, 1, 4, 3);
+ check_face(L, meshtbl, "faces", 1, 0, 1, 3);
+ check_face(L, meshtbl, "faces", 2, 0, 3, 2);
}
diff --git a/src/main.c b/src/main.c
index 618b30c..a986096 100644
--- a/src/main.c
+++ b/src/main.c
@@ -10,6 +10,7 @@
#include "logging/logging.h"
#include "options/options.h"
+void print_load_error(lua_State *L, const char *script_file, int error_type);
int main(int argc, char **argv)
{
@@ -38,7 +39,7 @@ int main(int argc, char **argv)
/* load main script */
int err = luaL_loadfile(L, options.script_file);
if (err != 0) {
- printf("cannot open file '%s'\n", options.script_file);
+ print_load_error(L, options.script_file, err);
lua_close(L);
return 0;
}
@@ -54,3 +55,25 @@ int main(int argc, char **argv)
lua_close(L);
return 0;
}
+
+
+void print_load_error(lua_State *L, const char *script_file, int error_type)
+{
+ switch(error_type) {
+ case LUA_ERRFILE:
+ printf("error: cannot open file '%s'\n", script_file);
+ break;
+
+ case LUA_ERRSYNTAX:
+ printf("error: failed to compile file: %s\n", lua_tostring(L, -1));
+ break;
+
+ case LUA_ERRMEM:
+ printf("error: memory error: %s\n", lua_tostring(L, -1));
+ break;
+
+ default:
+ printf("error: an unknown error occured when trying to load file '%s'.\n", script_file);
+ break;
+ };
+}
--
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