From 0cd447dbcf2b35fcbb2c0ae490ffbfea400f3334 Mon Sep 17 00:00:00 2001
From: jnmartin84 <jnmartin84@gmail.com>
Date: Sun, 13 Jul 2025 00:16:43 -0400
Subject: [PATCH] don't waste a full byte on mirror/flip setting moved MIRROR
 bits into bits 2 and 3 of what used to be `uv_clamp` member of TextureObject
 renamed `uv_clamp` member to `uv_wrap` updated and commented code accessing
 `uv_wrap` for both clamp and mirror settings

---
 GL/private.h |  6 ++----
 GL/state.c   |  6 ++++--
 GL/texture.c | 22 +++++++++++-----------
 3 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/GL/private.h b/GL/private.h
index 5ba1834..bdf9cb7 100644
--- a/GL/private.h
+++ b/GL/private.h
@@ -138,7 +138,7 @@ typedef struct {
     GLubyte mipmap_bias;
     GLubyte  env;
     GLubyte mipmapCount; /* The number of mipmap levels */
-    GLubyte  uv_clamp;
+    GLubyte  uv_wrap; /* clamp and flip settings for u and v */
     //40
     /* Mipmap textures have a different
      * offset for the base level when supplying the data, this
@@ -153,9 +153,7 @@ typedef struct {
     //50
     GLenum internalFormat;
     //54
-    GLubyte uv_flip;
-    // 55
-    GLubyte padding[9];  // Pad to 64-bytes
+    GLubyte padding[10];  // Pad to 64-bytes
 } __attribute__((aligned(32))) TextureObject;
 
 typedef struct {
diff --git a/GL/state.c b/GL/state.c
index 4d70b38..e667cdc 100644
--- a/GL/state.c
+++ b/GL/state.c
@@ -390,8 +390,10 @@ void _glUpdatePVRTextureContext(PolyContext *context, GLshort textureUnit) {
         }
 
         context->txr.env = tx1->env;
-        context->txr.uv_flip = tx1->uv_flip;
-        context->txr.uv_clamp = tx1->uv_clamp;
+        // extract mirror setting from bits 2 and 3 of uv_wrap by shifting out the clamp bits and masking
+        context->txr.uv_flip = (tx1->uv_wrap >> 2) & 3;
+        // extract clamp setting from bits 0 and 1 of uv_wrap by masking
+        context->txr.uv_clamp = tx1->uv_wrap & 3;
     }
 }
 
diff --git a/GL/texture.c b/GL/texture.c
index f6cbc35..fdf1c6e 100644
--- a/GL/texture.c
+++ b/GL/texture.c
@@ -14,12 +14,13 @@
  * issues with the allocator */
 #define PVR_MEM_BUFFER_SIZE (64 * 1024)
 
+/* Clamp settings go in lower bits of uv_wrap
+ * Mirror settings go in upper bits */
+#define MIRROR_U (1<<3)
+#define MIRROR_V (1<<2)
 #define CLAMP_U (1<<1)
 #define CLAMP_V (1<<0)
 
-#define MIRROR_U (1<<1)
-#define MIRROR_V (1<<0)
-
 static TextureObject* TEXTURE_UNITS[MAX_GLDC_TEXTURE_UNITS] = {NULL, NULL};
 static NamedArray TEXTURE_OBJECTS;
 GLubyte ACTIVE_TEXTURE = 0;
@@ -507,8 +508,7 @@ static void _glInitializeTextureObject(TextureObject* txr, unsigned int id) {
     txr->index = id;
     txr->width = txr->height = 0;
     txr->mipmap = 0;
-    txr->uv_clamp = 0;
-    txr->uv_flip = 0;
+    txr->uv_wrap = 0;
     txr->env = GPU_TXRENV_MODULATEALPHA;
     txr->data = NULL;
     txr->mipmapCount = 0;
@@ -1897,15 +1897,15 @@ void APIENTRY glTexParameteri(GLenum target, GLenum pname, GLint param) {
                 switch(param) {
                     case GL_CLAMP_TO_EDGE:
                     case GL_CLAMP:
-                        active->uv_clamp |= CLAMP_U;
+                        active->uv_wrap |= CLAMP_U;
                         break;
 
                     case GL_REPEAT:
-                        active->uv_clamp &= ~CLAMP_U;
+                        active->uv_wrap &= ~CLAMP_U;
                         break;
 
                     case GL_MIRRORED_REPEAT:
-                        active->uv_flip |= MIRROR_U;
+                        active->uv_wrap |= MIRROR_U;
                         break;
                 }
 
@@ -1915,15 +1915,15 @@ void APIENTRY glTexParameteri(GLenum target, GLenum pname, GLint param) {
                 switch(param) {
                     case GL_CLAMP_TO_EDGE:
                     case GL_CLAMP:
-                        active->uv_clamp |= CLAMP_V;
+                        active->uv_wrap |= CLAMP_V;
                         break;
 
                     case GL_REPEAT:
-                        active->uv_clamp &= ~CLAMP_V;
+                        active->uv_wrap &= ~CLAMP_V;
                         break;
 
                     case GL_MIRRORED_REPEAT:
-                        active->uv_flip |= MIRROR_V;
+                        active->uv_wrap |= MIRROR_V;
                         break;
                 }