shithub: cstory

Info  •  Files  •  Log  •  Branches

Fix out-of-bounds font atlas accesses

--- a/src/Font.cpp

+++ b/src/Font.cpp

@@ -12,6 +12,8 @@

 #include "File.h"

 #include "Backends/Rendering.h"

+#define MAX(a,b) ((a) > (b) ? (a) : (b))

+

 // Cave Story wasn't intended to use font anti-aliasing. It's only because Microsoft enabled it

 // by default from Windows Vista onwards that the game started using it.

 // Font anti-aliasing conflicts with the game's colour-keying, causing ugly artifacting around

@@ -1080,11 +1082,12 @@

 					size_t atlas_entry_width = FT_MulFix(font_object->face->bbox.xMax - font_object->face->bbox.xMin + 1, font_object->face->size->metrics.x_scale) / 64;

 					size_t atlas_entry_height = FT_MulFix(font_object->face->bbox.yMax - font_object->face->bbox.yMin + 1, font_object->face->size->metrics.y_scale) / 64;

-					font_object->atlas_row_length = ceil(sqrt(atlas_entry_width * atlas_entry_height * TOTAL_GLYPH_SLOTS) / atlas_entry_width);

+					size_t atlas_columns = ceil(sqrt(atlas_entry_width * atlas_entry_height * TOTAL_GLYPH_SLOTS) / atlas_entry_width);

+					size_t atlas_rows = ceil(sqrt(atlas_entry_width * atlas_entry_height * TOTAL_GLYPH_SLOTS) / atlas_entry_height);

-					size_t texture_size = font_object->atlas_row_length * atlas_entry_width;

+					font_object->atlas_row_length = atlas_columns;

-					font_object->atlas = RenderBackend_CreateGlyphAtlas(texture_size);

+					font_object->atlas = RenderBackend_CreateGlyphAtlas(MAX(atlas_columns * atlas_entry_width, atlas_rows * atlas_entry_height));

 					if (font_object->atlas != NULL)

 					{