From 7d265622774e4cdc1b3d784639b2ac21dce916d6 Mon Sep 17 00:00:00 2001
From: UnknownShadow200 <unknownshadow200@gmail.com>
Date: Sat, 6 Jan 2024 11:07:55 +1100
Subject: [PATCH] N64: Try to avoid crash when although width * height * pixel
 size of a texture fits within 4096 bytes, after aligning each row to 8 bytes,
 row pitch * height does not fit within 4096 bytes

---
 src/Graphics_N64.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/Graphics_N64.c b/src/Graphics_N64.c
index 6daf9a4aa..2c165205f 100644
--- a/src/Graphics_N64.c
+++ b/src/Graphics_N64.c
@@ -121,12 +121,19 @@ typedef struct CCTexture {
 	GLuint textureID;
 } CCTexture;
 
+#define ALIGNUP8(size) (((size) + 7) & ~0x07)
+
 // A8 B8 G8 R8 > A1 B5 G5 B5
 #define To16BitPixel(src) \
 	((src & 0x80) >> 7) | ((src & 0xF800) >> 10) | ((src & 0xF80000) >> 13) | ((src & 0xF8000000) >> 16);	
 
 static GfxResourceID Gfx_AllocTexture(struct Bitmap* bmp, cc_uint8 flags, cc_bool mipmaps) {
 	cc_bool bit16  = flags & TEXTURE_FLAG_LOWRES;
+	// rows are actually 8 byte aligned in TMEM https://github.com/DragonMinded/libdragon/blob/f360fa1bb1fb3ff3d98f4ab58692d40c828636c9/src/rdpq/rdpq_tex.c#L132
+	// so even though width * height * pixel size may fit within 4096 bytes, after adjusting for 8 byte alignment, row pitch * height may exceed 4096 bytes
+	int pitch = bit16 ? ALIGNUP8(bmp->width * 2) : ALIGNUP8(bmp->width * 4);
+	if (pitch * bmp->height > 4096) return 0;
+	
 	CCTexture* tex = Mem_Alloc(1, sizeof(CCTexture), "texture");
 	
 	glGenTextures(1, &tex->textureID);