Add Mipmap LOD Bias to texture layers.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@2133 dfc29bdd-3216-0410-991c-e03cc46cb475

include/SMaterialLayer.h

@@ -45,7 +45,9 @@ namespace video
 				TextureWrap(ETC_REPEAT),
 				BilinearFilter(true),
 				TrilinearFilter(false),
-				AnisotropicFilter(0), TextureMatrix(0)
+				AnisotropicFilter(0),
+				LODBias(0),
+				TextureMatrix(0)
 			{}
 
 		//! Copy constructor
@@ -99,6 +101,7 @@ namespace video
 			BilinearFilter = other.BilinearFilter;
 			TrilinearFilter = other.TrilinearFilter;
 			AnisotropicFilter = other.AnisotropicFilter;
+			LODBias = other.LODBias;
 
 			return *this;
 		}
@@ -107,15 +110,15 @@ namespace video
 		ITexture* Texture;
 
 		//! Texture Clamp Mode
-		E_TEXTURE_CLAMP TextureWrap;
+		u8 TextureWrap;
 
 		//! Is bilinear filtering enabled? Default: true
-		bool BilinearFilter;
+		bool BilinearFilter:1;
 
 		//! Is trilinear filtering enabled? Default: false
 		/** If the trilinear filter flag is enabled,
 		the bilinear filtering flag is ignored. */
-		bool TrilinearFilter;
+		bool TrilinearFilter:1;
 
 		//! Is anisotropic filtering enabled? Default: 0, disabled
 		/** In Irrlicht you can use anisotropic texture filtering
@@ -126,6 +129,13 @@ namespace video
 		Value 1 is equivalent to 0, but should be avoided. */
 		u8 AnisotropicFilter;
 
+		//! Bias for the mipmap choosing decision.
+		/** This value can make the textures more or less blurry than with the
+		default value of 0. The value (divided by 8.f) is added to the mipmap level
+		chosen initially, and thus takes a smaller mipmap for a region
+		if the value is positive. */
+		s8 LODBias;
+
 		//! Gets the texture transformation matrix
 		/** \return Texture matrix of this layer. */
 		core::matrix4& getTextureMatrix()
@@ -171,7 +181,8 @@ namespace video
 				TextureWrap != b.TextureWrap ||
 				BilinearFilter != b.BilinearFilter ||
 				TrilinearFilter != b.TrilinearFilter ||
-				AnisotropicFilter != b.AnisotropicFilter;
+				AnisotropicFilter != b.AnisotropicFilter ||
+				LODBias != b.LODBias;
 			if (different)
 				return true;
 			else

source/Irrlicht/CD3D8Driver.cpp

@@ -1469,6 +1469,12 @@ void CD3D8Driver::setBasicRenderStates(const SMaterial& material, const SMateria
 	// texture address mode
 	for (u32 st=0; st<MaxTextureUnits; ++st)
 	{
+		if (resetAllRenderstates || lastmaterial.TextureLayer[st].LODBias != material.TextureLayer[st].LODBias)
+		{
+			const float tmp = material.TextureLayer[st].LODBias * 0.125f;
+			pID3DDevice->SetTextureStageState(st, D3DSAMP_MIPMAPLODBIAS, *(DWORD*)(&tmp));
+		}
+
 		if (resetAllRenderstates || lastmaterial.TextureLayer[st].TextureWrap != material.TextureLayer[st].TextureWrap)
 		{
 			u32 mode = D3DTADDRESS_WRAP;

source/Irrlicht/CD3D9Driver.cpp

@@ -1828,6 +1828,12 @@ void CD3D9Driver::setBasicRenderStates(const SMaterial& material, const SMateria
 	// texture address mode
 	for (u32 st=0; st<MaxTextureUnits; ++st)
 	{
+		if (resetAllRenderstates || lastmaterial.TextureLayer[st].LODBias != material.TextureLayer[st].LODBias)
+		{
+			const float tmp = material.TextureLayer[st].LODBias * 0.125f;
+			pID3DDevice->SetSamplerState(st, D3DSAMP_MIPMAPLODBIAS, *(DWORD*)(&tmp));
+		}
+
 		if (resetAllRenderstates || lastmaterial.TextureLayer[st].TextureWrap != material.TextureLayer[st].TextureWrap)
 		{
 			u32 mode = D3DTADDRESS_WRAP;

source/Irrlicht/COpenGLDriver.cpp

@@ -2013,6 +2013,19 @@ void COpenGLDriver::setBasicRenderStates(const SMaterial& material, const SMater
 		else if (i>0)
 			break;
 
+#ifdef EXT_texture_lod_bias
+		if (FeatureAvailable[IRR_EXT_texture_lod_bias])
+		{
+			if (material.TextureLayer[i].LODBias)
+			{
+				const float tmp = core::clamp(material.TextureLayer[i].LODBias * 0.125f, -MaxTextureLODBias, MaxTextureLODBias);
+				glTexEnvf(GL_TEXTURE_FILTER_CONTROL_EXT, GL_TEXTURE_LOD_BIAS_EXT, tmp);
+			}
+			else
+				glTexEnvf(GL_TEXTURE_FILTER_CONTROL_EXT, GL_TEXTURE_LOD_BIAS_EXT, 0.f);
+		}
+#endif
+
 		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,
 			(material.TextureLayer[i].BilinearFilter || material.TextureLayer[i].TrilinearFilter) ? GL_LINEAR : GL_NEAREST);
 

source/Irrlicht/COpenGLExtensionHandler.cpp

@@ -21,7 +21,7 @@ COpenGLExtensionHandler::COpenGLExtensionHandler() :
 		TextureCompressionExtension(false),
 		MaxTextureUnits(1), MaxLights(1), MaxAnisotropy(1), MaxUserClipPlanes(0),
 		MaxAuxBuffers(0), MaxIndices(65535), MaxTextureSize(1),
-		Version(0), ShaderLanguageVersion(0)
+		MaxTextureLODBias(0.f), Version(0), ShaderLanguageVersion(0)
 #ifdef _IRR_OPENGL_USE_EXTPOINTER_
 	,pGlActiveTextureARB(0), pGlClientActiveTextureARB(0),
 	pGlGenProgramsARB(0), pGlBindProgramARB(0), pGlProgramStringARB(0),
@@ -411,6 +411,10 @@ void COpenGLExtensionHandler::initExtensions(bool stencilBuffer)
 #endif
 	glGetIntegerv(GL_MAX_TEXTURE_SIZE, &num);
 	MaxTextureSize=static_cast<u32>(num);
+#ifdef EXT_texture_lod_bias
+	if (FeatureAvailable[IRR_EXT_texture_lod_bias])
+		glGetFloatv(GL_MAX_TEXTURE_LOD_BIAS_EXT, &MaxTextureLODBias);
+#endif
 	glGetIntegerv(GL_MAX_CLIP_PLANES, &num);
 	MaxUserClipPlanes=static_cast<u8>(num);
 	glGetIntegerv(GL_AUX_BUFFERS, &num);

source/Irrlicht/COpenGLExtensionHandler.h

@@ -725,6 +725,8 @@ class COpenGLExtensionHandler
 	u32 MaxIndices;
 	//! Maximal texture dimension
 	u32 MaxTextureSize;
+	//! Maximal LOD Bias
+	f32 MaxTextureLODBias;
 
 	//! OpenGL version as Integer: 100*Major+Minor, i.e. 2.1 becomes 201
 	u16 Version;