From 98c06bcbc8359a5cdd8e7c75455171dd39bb7fce Mon Sep 17 00:00:00 2001
From: Taylor Richards <taylor@icculus.org>
Date: Mon, 4 Jul 2016 11:47:58 -0400
Subject: [PATCH] handle npot textures properly to base spec

---
 include/2d.h                  |  5 +++++
 src/graphics/grgl2.cpp        |  8 --------
 src/graphics/grgl2texture.cpp | 31 +++++++++++++++++++------------
 3 files changed, 24 insertions(+), 20 deletions(-)

diff --git a/include/2d.h b/include/2d.h
index 9b26da6..7a97549 100644
--- a/include/2d.h
+++ b/include/2d.h
@@ -734,5 +734,10 @@ inline int next_pow2(int p)
 	return p+1;
 }
 
+inline int is_pow2(int p)
+{
+	return (p && !(p & (p-1)));
+}
+
 #endif
 
diff --git a/src/graphics/grgl2.cpp b/src/graphics/grgl2.cpp
index 2989106..99a55d6 100644
--- a/src/graphics/grgl2.cpp
+++ b/src/graphics/grgl2.cpp
@@ -22,8 +22,6 @@
 
 int GL_two_inited = 0;
 
-bool Use_mipmaps = false;
-
 static GLuint FB_texture = 0;
 static GLuint FB_id = 0;
 static GLuint FB_rb_id = 0;
@@ -303,12 +301,6 @@ int opengl2_init()
 	glPixelStorei(GL_PACK_ALIGNMENT, 1);
 	glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 
-	if ( SDL_GL_ExtensionSupported("GL_OES_texture_npot") ) {
-		Use_mipmaps	= true;
-	}
-
-	mprintf(("  Mipmaps  : %s\n", Use_mipmaps ? "Enabled" : "Disabled"));
-
 	glFlush();
 
 	gr_opengl_clear();
diff --git a/src/graphics/grgl2texture.cpp b/src/graphics/grgl2texture.cpp
index e6b8020..f6d7062 100644
--- a/src/graphics/grgl2texture.cpp
+++ b/src/graphics/grgl2texture.cpp
@@ -49,8 +49,6 @@ static ubyte GL_xlat[256] = { 0 };
 extern int Gr_textures_in;
 extern int bm_get_cache_slot( int bitmap_id, int separate_ani_frames );
 
-extern bool Use_mipmaps;
-
 
 void opengl2_set_texture_state(gr_texture_source ts)
 {
@@ -209,8 +207,7 @@ static int opengl2_create_texture_sub(int bitmap_handle, int bitmap_type, bitmap
 
 	glBindTexture(GL_TEXTURE_2D, t->texture_handle);
 
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+	GLint wrap_mode = GL_CLAMP_TO_EDGE;
 
 	glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 	glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
@@ -261,6 +258,8 @@ static int opengl2_create_texture_sub(int bitmap_handle, int bitmap_type, bitmap
 		}
 
 		default: {
+			wrap_mode = GL_REPEAT;
+
 			if (resize) {
 				texmem = (ubyte *) malloc(tex_w * tex_h * 2);
 				texmemp = texmem;
@@ -296,21 +295,20 @@ static int opengl2_create_texture_sub(int bitmap_handle, int bitmap_type, bitmap
 				free(texmem);
 			}
 
-			if (Use_mipmaps) {
-				glGenerateMipmap(GL_TEXTURE_2D);
+			glGenerateMipmap(GL_TEXTURE_2D);
 
-				glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST_MIPMAP_LINEAR);
-				t->is_mipmaped = 1;
+			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST_MIPMAP_LINEAR);
+			t->is_mipmaped = 1;
 
-				size = fl2i(tex_w * tex_h * 2.0f * 1.3333333f);
-			} else {
-				size = tex_w * tex_h * 2;
-			}
+			size = fl2i(tex_w * tex_h * 2.0f * 1.3333333f);
 
 			break;
 		}
 	}
 
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, wrap_mode);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, wrap_mode);
+
 	t->bitmap_id = bitmap_handle;
 	t->time_created = GL_frame_count;
 	t->used_this_frame = 0;
@@ -380,6 +378,15 @@ static int opengl2_create_texture(int bitmap_handle, int bitmap_type, tcache_slo
 		max_h /= val;
 	}
 
+	if ( (bitmap_type == TCACHE_TYPE_NORMAL) || (bitmap_type == TCACHE_TYPE_XPARENT) ) {
+		if ( !is_pow2(max_w) || !is_pow2(max_h) ) {
+			resize = true;
+
+			max_w = next_pow2(max_w);
+			max_h = next_pow2(max_h);
+		}
+	}
+
 	if ( (max_w < 1) || (max_h < 1) ) {
 		mprintf(("Bitmap %d is too small at %dx%d\n", bitmap_handle, max_w, max_h));
 		return 0;
-- 
2.39.2