From: Mikko Rasa <tdb@tdb.fi>
Date: Mon, 2 Jul 2018 12:49:48 +0000 (+0300)
Subject: Allow the maximum mipmap level of a texture to be specified
X-Git-Url: http://git.tdb.fi/?a=commitdiff_plain;h=40e1eba6c489e11a4c9b8865ddcd3ec3d9f83818;p=libs%2Fgl.git

Allow the maximum mipmap level of a texture to be specified

This doubles as a way to specify the number of mipmap levels to allocate
when the tetxure image is loaded from a Graphics::Image.
---

diff --git a/source/texture.cpp b/source/texture.cpp
index 820dd10f..719d4a56 100644
--- a/source/texture.cpp
+++ b/source/texture.cpp
@@ -63,6 +63,7 @@ Texture::Texture(GLenum t, ResourceManager *m):
 	ifmt(RGB),
 	min_filter(NEAREST_MIPMAP_LINEAR),
 	mag_filter(LINEAR),
+	mipmap_levels(0),
 	max_anisotropy(1.0f),
 	wrap_s(REPEAT),
 	wrap_t(REPEAT),
@@ -178,6 +179,8 @@ void Texture::update_parameter(int mask) const
 				glTexParameteriv(target, GL_TEXTURE_SWIZZLE_RGBA, swizzle_orders+swizzle*4);
 		}
 	}
+	if(mask&MIPMAP_LEVELS)
+		set_parameter_i(GL_TEXTURE_MAX_LEVEL, (mipmap_levels ? mipmap_levels-1 : 1000));
 }
 
 void Texture::set_parameter_i(GLenum param, int value) const
@@ -214,6 +217,12 @@ void Texture::set_filter(TextureFilter f)
 	set_mag_filter(f==NEAREST ? NEAREST : LINEAR);
 }
 
+void Texture::set_mipmap_levels(unsigned l)
+{
+	mipmap_levels = l;
+	update_parameter(MIPMAP_LEVELS);
+}
+
 void Texture::set_max_anisotropy(float a)
 {
 	if(a<1.0f)
@@ -403,6 +412,7 @@ void Texture::Loader::init()
 	add("mag_filter", &Loader::mag_filter);
 	add("max_anisotropy", &Loader::max_anisotropy);
 	add("min_filter", &Loader::min_filter);
+	add("mipmap_levels", &Loader::mipmap_levels);
 	add("wrap",       &Loader::wrap);
 	add("wrap_r",     &Loader::wrap_r);
 	add("wrap_s",     &Loader::wrap_s);
@@ -452,6 +462,11 @@ void Texture::Loader::min_filter(TextureFilter f)
 	obj.set_min_filter(f);
 }
 
+void Texture::Loader::mipmap_levels(unsigned l)
+{
+	obj.set_mipmap_levels(l);
+}
+
 void Texture::Loader::wrap(TextureWrap w)
 {
 	obj.set_wrap(w);
diff --git a/source/texture.h b/source/texture.h
index ffc5e1a4..94614c45 100644
--- a/source/texture.h
+++ b/source/texture.h
@@ -88,6 +88,7 @@ protected:
 		void mag_filter(TextureFilter);
 		void max_anisotropy(float);
 		void min_filter(TextureFilter);
+		void mipmap_levels(unsigned);
 		void wrap(TextureWrap);
 		void wrap_r(TextureWrap);
 		void wrap_s(TextureWrap);
@@ -105,7 +106,8 @@ protected:
 		COMPARE = 64,
 		COMPARE_FUNC = 128,
 		MAX_ANISOTROPY = 256,
-		FORMAT_SWIZZLE = 512
+		FORMAT_SWIZZLE = 512,
+		MIPMAP_LEVELS = 1024
 	};
 
 	enum FormatSwizzle
@@ -121,6 +123,7 @@ protected:
 	FormatSwizzle swizzle;
 	TextureFilter min_filter;
 	TextureFilter mag_filter;
+	unsigned mipmap_levels;
 	float max_anisotropy;
 	TextureWrap wrap_s;
 	TextureWrap wrap_t;
@@ -154,6 +157,8 @@ public:
 	is not applicable to magnification, LINEAR is used instead. */
 	void set_filter(TextureFilter);
 
+	void set_mipmap_levels(unsigned);
+
 	void set_max_anisotropy(float);
 
 	/** Sets the wrapping mode for all coordinates. */
diff --git a/source/texture1d.cpp b/source/texture1d.cpp
index a1ee418b..7466a9ef 100644
--- a/source/texture1d.cpp
+++ b/source/texture1d.cpp
@@ -108,7 +108,7 @@ void Texture1D::image(const Graphics::Image &img, bool srgb)
 	PixelFormat fmt = pixelformat_from_graphics(img.get_format());
 	if(width==0)
 	{
-		unsigned l = (is_mipmapped(min_filter) ? 0 : 1);
+		unsigned l = (is_mipmapped(min_filter) ? mipmap_levels ? mipmap_levels : 0 : 1);
 		storage(storage_pixelformat_from_graphics(img.get_format(), srgb), w, l);
 	}
 	else if(w!=width)
diff --git a/source/texture2d.cpp b/source/texture2d.cpp
index 44ee6406..45c2e665 100644
--- a/source/texture2d.cpp
+++ b/source/texture2d.cpp
@@ -141,7 +141,7 @@ void Texture2D::image(const Graphics::Image &img, bool srgb, bool from_buffer)
 	PixelFormat fmt = pixelformat_from_graphics(img.get_format());
 	if(width==0)
 	{
-		unsigned l = (is_mipmapped(min_filter) ? 0 : 1);
+		unsigned l = (is_mipmapped(min_filter) ? mipmap_levels ? mipmap_levels : 0 : 1);
 		storage(storage_pixelformat_from_graphics(img.get_format(), srgb), w, h, l);
 	}
 	else if(w!=width || h!=height)
diff --git a/source/texture3d.cpp b/source/texture3d.cpp
index 36fdfa0f..ed5619cb 100644
--- a/source/texture3d.cpp
+++ b/source/texture3d.cpp
@@ -188,7 +188,7 @@ void Texture3D::image(const Graphics::Image &img, bool srgb)
 	PixelFormat fmt = pixelformat_from_graphics(img.get_format());
 	if(width==0)
 	{
-		unsigned l = (is_mipmapped(min_filter) ? 0 : 1);
+		unsigned l = (is_mipmapped(min_filter) ? mipmap_levels ? mipmap_levels : 0 : 1);
 		storage(storage_pixelformat_from_graphics(img.get_format(), srgb), w, h, d, l);
 	}
 	else if(w!=width || h!=height || d!=depth)
diff --git a/source/texturecube.cpp b/source/texturecube.cpp
index ee8c71c5..03e65167 100644
--- a/source/texturecube.cpp
+++ b/source/texturecube.cpp
@@ -161,7 +161,7 @@ void TextureCube::image(const Graphics::Image &img, bool srgb)
 	PixelFormat fmt = pixelformat_from_graphics(img.get_format());
 	if(size==0)
 	{
-		unsigned l = (is_mipmapped(min_filter) ? 0 : 1);
+		unsigned l = (is_mipmapped(min_filter) ? mipmap_levels ? mipmap_levels : 0 : 1);
 		storage(storage_pixelformat_from_graphics(img.get_format(), srgb), w, l);
 	}
 	else if(w!=size || h!=size)