From e8f39600b2eae0a57c6ef7a9ba1b90840e85a118 Mon Sep 17 00:00:00 2001
From: havoc <havoc@d7cf8633-e32d-0410-b094-e92efae38249>
Date: Sun, 13 Jul 2003 10:22:32 +0000
Subject: [PATCH] GL_EXT_texture_filter_anisotropic support (thanks zinx!)

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@3265 d7cf8633-e32d-0410-b094-e92efae38249
---
 gl_textures.c | 4 ++++
 glquake.h     | 6 +++++-
 vid_shared.c  | 8 ++++++--
 3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/gl_textures.c b/gl_textures.c
index e1ccf153..bcfc554f 100644
--- a/gl_textures.c
+++ b/gl_textures.c
@@ -8,6 +8,7 @@ cvar_t	r_max_scrapsize = {CVAR_SAVE, "r_max_scrapsize", "256"};
 cvar_t	r_picmip = {CVAR_SAVE, "r_picmip", "0"};
 cvar_t	r_lerpimages = {CVAR_SAVE, "r_lerpimages", "1"};
 cvar_t	r_precachetextures = {CVAR_SAVE, "r_precachetextures", "1"};
+cvar_t  gl_texture_anisotropy = {CVAR_SAVE, "gl_texture_anisotropy", "0"};
 
 int		gl_filter_min = GL_LINEAR_MIPMAP_LINEAR;
 int		gl_filter_mag = GL_LINEAR;
@@ -519,6 +520,7 @@ void R_Textures_Init (void)
 	Cvar_RegisterVariable (&r_picmip);
 	Cvar_RegisterVariable (&r_lerpimages);
 	Cvar_RegisterVariable (&r_precachetextures);
+	Cvar_RegisterVariable (&gl_texture_anisotropy);
 
 	R_RegisterModule("R_Textures", r_textures_start, r_textures_shutdown, r_textures_newmap);
 }
@@ -565,6 +567,8 @@ static void GL_SetupTextureParameters(int flags, int texturetype)
 
 	CHECKGLERROR
 
+	if (gl_support_anisotropy)
+		qglTexParameterf(textureenum, GL_TEXTURE_MAX_ANISOTROPY_EXT, gl_texture_anisotropy.value);
 	qglTexParameteri(textureenum, GL_TEXTURE_WRAP_S, wrapmode);
 	qglTexParameteri(textureenum, GL_TEXTURE_WRAP_T, wrapmode);
 	if (gltexturetypedimensions[texturetype] >= 3)
diff --git a/glquake.h b/glquake.h
index 69542c0e..d6be002f 100644
--- a/glquake.h
+++ b/glquake.h
@@ -121,6 +121,10 @@ typedef double GLclampd;
 #define GL_LINEAR_MIPMAP_NEAREST		0x2701
 #define GL_LINEAR_MIPMAP_LINEAR			0x2703
 
+extern int gl_support_anisotropy;
+#define GL_TEXTURE_MAX_ANISOTROPY_EXT		0x84FE
+#define GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT	0x84FF
+
 #define GL_DECAL				0x2101
 #define GL_MODULATE				0x2100
 
@@ -444,7 +448,7 @@ extern void (GLAPIENTRY *qglClearStencil)(GLint s);
 
 //extern void (GLAPIENTRY *qglTexEnvf)(GLenum target, GLenum pname, GLfloat param);
 extern void (GLAPIENTRY *qglTexEnvi)(GLenum target, GLenum pname, GLint param);
-//extern void (GLAPIENTRY *qglTexParameterf)(GLenum target, GLenum pname, GLfloat param);
+extern void (GLAPIENTRY *qglTexParameterf)(GLenum target, GLenum pname, GLfloat param);
 //extern void (GLAPIENTRY *qglTexParameterfv)(GLenum target, GLenum pname, GLfloat *params);
 extern void (GLAPIENTRY *qglTexParameteri)(GLenum target, GLenum pname, GLint param);
 
diff --git a/vid_shared.c b/vid_shared.c
index 8dd32054..76d3c75b 100644
--- a/vid_shared.c
+++ b/vid_shared.c
@@ -30,6 +30,8 @@ int gl_support_clamptoedge = false;
 int gl_support_var = false;
 // GL_NV_vertex_array_range2
 int gl_support_var2 = false;
+// GL_EXT_texture_filter_anisotropic
+int gl_support_anisotropy = false;
 
 // LordHavoc: if window is hidden, don't update screen
 int vid_hidden = true;
@@ -188,7 +190,7 @@ void (GLAPIENTRY *qglClearStencil)(GLint s);
 
 //void (GLAPIENTRY *qglTexEnvf)(GLenum target, GLenum pname, GLfloat param);
 void (GLAPIENTRY *qglTexEnvi)(GLenum target, GLenum pname, GLint param);
-//void (GLAPIENTRY *qglTexParameterf)(GLenum target, GLenum pname, GLfloat param);
+void (GLAPIENTRY *qglTexParameterf)(GLenum target, GLenum pname, GLfloat param);
 //void (GLAPIENTRY *qglTexParameterfv)(GLenum target, GLenum pname, GLfloat *params);
 void (GLAPIENTRY *qglTexParameteri)(GLenum target, GLenum pname, GLint param);
 
@@ -328,7 +330,7 @@ static dllfunction_t opengl110funcs[] =
 	{"glClearStencil", (void **) &qglClearStencil},
 //	{"glTexEnvf", (void **) &qglTexEnvf},
 	{"glTexEnvi", (void **) &qglTexEnvi},
-//	{"glTexParameterf", (void **) &qglTexParameterf},
+	{"glTexParameterf", (void **) &qglTexParameterf},
 //	{"glTexParameterfv", (void **) &qglTexParameterfv},
 	{"glTexParameteri", (void **) &qglTexParameteri},
 //	{"glPixelStoref", (void **) &qglPixelStoref},
@@ -452,6 +454,8 @@ void VID_CheckExtensions(void)
 	if (gl_support_var)
 		gl_support_var2 = GL_CheckExtension("GL_NV_vertex_array_range2", NULL, "-novar2", false);
 
+	gl_support_anisotropy = GL_CheckExtension("GL_EXT_texture_filter_anisotropic", NULL, "-noanisotropy", false);
+
 	// we don't care if it's an extension or not, they are identical functions, so keep it simple in the rendering code
 	if (qglDrawRangeElements == NULL)
 		qglDrawRangeElements = qglDrawRangeElementsEXT;
-- 
2.39.2