public: move atlas packing code from renderer, add tests

public/atlas.c

@@ -0,0 +1,62 @@
+/*
+atlas.c - generic 2D atlas packer (strip-based)
+Copyright (C) 1997 id Software
+Copyright (C) Xash3D and Xash3D FWGS developers
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+*/
+#include "atlas.h"
+
+qboolean Atlas_AllocBlock( atlas_t *atlas, int w, int h, int *x, int *y )
+{
+	int i, j;
+	int best, best2;
+	int size = atlas->size;
+
+	best = size;
+
+	for( i = 0; i <= size - w; )
+	{
+		best2 = 0;
+
+		for( j = 0; j < w; j++ )
+		{
+			if( atlas->allocated[i + j] >= best )
+				break;
+			if( atlas->allocated[i + j] > best2 )
+				best2 = atlas->allocated[i + j];
+		}
+
+		if( j == w )
+		{
+			*x = i;
+			*y = best = best2;
+			if( best == 0 )
+				break;
+			i++;
+		}
+		else
+		{
+			i += j + 1;
+		}
+	}
+
+	if( best + h > size )
+		return false;
+
+	for( i = 0; i < w; i++ )
+		atlas->allocated[*x + i] = best + h;
+
+	if( best + h > atlas->max_height )
+		atlas->max_height = best + h;
+
+	return true;
+}

public/atlas.h

@@ -0,0 +1,41 @@
+/*
+atlas.h - generic 2D atlas packer (strip-based)
+Copyright (C) 1997 id Software
+Copyright (C) Xash3D and Xash3D FWGS developers
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+*/
+#ifndef ATLAS_H
+#define ATLAS_H
+
+#include <string.h>
+#include "xash3d_types.h"
+
+// maximum atlas dimension
+#define ATLAS_MAX_SIZE 1024
+
+typedef struct atlas_s
+{
+	int allocated[ATLAS_MAX_SIZE];
+	int size;
+	int max_height;
+} atlas_t;
+
+static inline void Atlas_Init( atlas_t *atlas, int size )
+{
+	memset( atlas->allocated, 0, sizeof( atlas->allocated ));
+	atlas->size = size;
+	atlas->max_height = 0;
+}
+
+qboolean Atlas_AllocBlock( atlas_t *atlas, int w, int h, int *x, int *y );
+
+#endif // ATLAS_H

public/tests/test_atlas.c

@@ -0,0 +1,131 @@
+#include "atlas.h"
+
+static int Test_BasicAlloc( void )
+{
+	atlas_t atlas;
+	int x, y;
+
+	Atlas_Init( &atlas, 128 );
+
+	if( !Atlas_AllocBlock( &atlas, 16, 16, &x, &y ))
+		return 1;
+
+	if( x != 0 || y != 0 )
+		return 2;
+
+	if( atlas.max_height != 16 )
+		return 3;
+
+	if( !Atlas_AllocBlock( &atlas, 16, 16, &x, &y ))
+		return 4;
+
+	if( x != 16 || y != 0 )
+		return 5;
+
+	return 0;
+}
+
+static int Test_Full( void )
+{
+	atlas_t atlas;
+	int x, y;
+
+	Atlas_Init( &atlas, 64 );
+
+	if( !Atlas_AllocBlock( &atlas, 64, 64, &x, &y ))
+		return 1;
+
+	if( Atlas_AllocBlock( &atlas, 1, 1, &x, &y ))
+		return 2;
+
+	return 0;
+}
+
+static int Test_Packing( void )
+{
+	atlas_t atlas;
+	int x, y;
+
+	Atlas_Init( &atlas, 64 );
+
+	if( !Atlas_AllocBlock( &atlas, 32, 16, &x, &y ))
+		return 1;
+
+	if( !Atlas_AllocBlock( &atlas, 32, 16, &x, &y ))
+		return 2;
+
+	if( x != 32 || y != 0 )
+		return 3;
+
+	if( !Atlas_AllocBlock( &atlas, 64, 16, &x, &y ))
+		return 4;
+
+	if( y != 16 )
+		return 5;
+
+	return 0;
+}
+
+static int Test_Reset( void )
+{
+	atlas_t atlas;
+	int x, y;
+
+	Atlas_Init( &atlas, 64 );
+
+	if( !Atlas_AllocBlock( &atlas, 64, 64, &x, &y ))
+		return 1;
+
+	Atlas_Init( &atlas, 64 );
+
+	if( !Atlas_AllocBlock( &atlas, 64, 64, &x, &y ))
+		return 2;
+
+	if( x != 0 || y != 0 )
+		return 3;
+
+	return 0;
+}
+
+static int Test_TooLarge( void )
+{
+	atlas_t atlas;
+	int x, y;
+
+	Atlas_Init( &atlas, 64 );
+
+	if( Atlas_AllocBlock( &atlas, 65, 1, &x, &y ))
+		return 1;
+
+	if( Atlas_AllocBlock( &atlas, 1, 65, &x, &y ))
+		return 2;
+
+	return 0;
+}
+
+int main( void )
+{
+	int ret;
+
+	ret = Test_BasicAlloc();
+	if( ret > 0 )
+		return ret;
+
+	ret = Test_Full();
+	if( ret > 0 )
+		return ret + 16;
+
+	ret = Test_Packing();
+	if( ret > 0 )
+		return ret + 32;
+
+	ret = Test_Reset();
+	if( ret > 0 )
+		return ret + 48;
+
+	ret = Test_TooLarge();
+	if( ret > 0 )
+		return ret + 64;
+
+	return 0;
+}

public/wscript

@@ -157,6 +157,7 @@ def build(bld):
 			'efp': 'tests/test_efp.c',
 			'atoi': 'tests/test_atoi.c',
 			'parsefile': 'tests/test_parsefile.c',
+			'atlas': 'tests/test_atlas.c',
 		}
 
 		for i in tests:

ref/gl/gl_rsurf.c

@@ -16,6 +16,7 @@ GNU General Public License for more details.
 #include "gl_local.h"
 #include "xash3d_mathlib.h"
 #include "mod_local.h"
+#include "atlas.h"
 
 #define TURBSCALE		( 256.0f / ( M_PI2 ))
 
@@ -27,8 +28,7 @@ static const float r_turbsin[] =
 
 typedef struct
 {
-	int		allocated[BLOCK_SIZE_MAX];
-	int		max_height;		// maximum height currently in use in the block
+	atlas_t		atlas;
 	int		current_lightmap_texture;
 	msurface_t	*dynamic_surfaces;
 	msurface_t	*lightmap_surfaces[MAX_LIGHTMAPS];
@@ -646,60 +646,17 @@ static void R_AddDynamicLights( const msurface_t *surf )
 */
 static void LM_InitBlock( void )
 {
-	memset( gl_lms.allocated, 0, sizeof( gl_lms.allocated ));
-	gl_lms.max_height = 0;
+	Atlas_Init( &gl_lms.atlas, BLOCK_SIZE );
 }
 
-static int LM_AllocBlock( int w, int h, int *x, int *y )
+static qboolean LM_AllocBlock( int w, int h, int *x, int *y )
 {
-	int	i, j;
-	int	best, best2;
-
-	best = BLOCK_SIZE;
-
-	for( i = 0; i < BLOCK_SIZE - w; )
-	{
-		best2 = 0;
-
-		for( j = 0; j < w; j++ )
-		{
-			if( gl_lms.allocated[i+j] >= best )
-				break;
-			if( gl_lms.allocated[i+j] > best2 )
-				best2 = gl_lms.allocated[i+j];
-		}
-
-		if( j == w )
-		{
-			// this is a valid spot
-			*x = i;
-			*y = best = best2;
-			if( best == 0 )
-				break; // height 0 is optimal, can't do better
-			i++;
-		}
-		else
-		{
-			// allocated[i+j] was too tall — no position in [i, i+j] can work
-			i += j + 1;
-		}
-	}
-
-	if( best + h > BLOCK_SIZE )
-		return false;
-
-	for( i = 0; i < w; i++ )
-		gl_lms.allocated[*x + i] = best + h;
-
-	if( best + h > gl_lms.max_height )
-		gl_lms.max_height = best + h;
-
-	return true;
+	return Atlas_AllocBlock( &gl_lms.atlas, w, h, x, y );
 }
 
 static void LM_UploadDynamicBlock( void )
 {
-	pglTexSubImage2D( GL_TEXTURE_2D, 0, 0, 0, BLOCK_SIZE, gl_lms.max_height, GL_RGBA, GL_UNSIGNED_BYTE, gl_lms.lightmap_buffer );
+	pglTexSubImage2D( GL_TEXTURE_2D, 0, 0, 0, BLOCK_SIZE, gl_lms.atlas.max_height, GL_RGBA, GL_UNSIGNED_BYTE, gl_lms.lightmap_buffer );
 }
 
 static void LM_UploadBlock( qboolean dynamic )