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<?xml version="1.0"?>
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
"http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd">
<refentry id="libg3d-texture">
<refmeta>
<refentrytitle role="top_of_page" id="libg3d-texture.top_of_page">texture</refentrytitle>
<manvolnum>3</manvolnum>
<refmiscinfo>LIBG3D Library</refmiscinfo>
</refmeta>
<refnamediv>
<refname>texture</refname>
<refpurpose>Texture loading and manipulation</refpurpose>
<!--[<xref linkend="desc" endterm="desc.title"/>]-->
</refnamediv>
<refsynopsisdiv id="libg3d-texture.synopsis" role="synopsis">
<title role="synopsis.title">Synopsis</title>
<synopsis>
#include <g3d/texture.h>
#define <link linkend="G3D-FLAG-IMG-GREYSCALE:CAPS">G3D_FLAG_IMG_GREYSCALE</link>
enum <link linkend="G3DTexEnv">G3DTexEnv</link>;
<link linkend="G3DImage">G3DImage</link>;
<link linkend="G3DImage">G3DImage</link>* <link linkend="g3d-texture-load-cached">g3d_texture_load_cached</link> (<link linkend="G3DContext">G3DContext</link> *context,
<link linkend="G3DModel">G3DModel</link> *model,
const <link linkend="gchar">gchar</link> *filename);
<link linkend="G3DImage">G3DImage</link>* <link linkend="g3d-texture-load-from-stream">g3d_texture_load_from_stream</link> (<link linkend="G3DContext">G3DContext</link> *context,
<link linkend="G3DModel">G3DModel</link> *model,
<link linkend="G3DStream">G3DStream</link> *stream);
<link linkend="G3DImage">G3DImage</link>* <link linkend="g3d-texture-load">g3d_texture_load</link> (<link linkend="G3DContext">G3DContext</link> *context,
const <link linkend="gchar">gchar</link> *filename);
<link linkend="void">void</link> <link linkend="g3d-texture-free">g3d_texture_free</link> (<link linkend="G3DImage">G3DImage</link> *texture);
<link linkend="gboolean">gboolean</link> <link linkend="g3d-texture-prepare">g3d_texture_prepare</link> (<link linkend="G3DImage">G3DImage</link> *texture);
<link linkend="gboolean">gboolean</link> <link linkend="g3d-texture-flip-y">g3d_texture_flip_y</link> (<link linkend="G3DImage">G3DImage</link> *texture);
<link linkend="G3DImage">G3DImage</link>* <link linkend="g3d-texture-merge-alpha">g3d_texture_merge_alpha</link> (<link linkend="G3DImage">G3DImage</link> *image,
<link linkend="G3DImage">G3DImage</link> *aimage);
</synopsis>
</refsynopsisdiv>
<refsect1 id="libg3d-texture.description" role="desc">
<title role="desc.title">Description</title>
<para>
A texture is an image used in materials. Here are some helper functions,
mostly for cached loading of a <link linkend="G3DImage"><type>G3DImage</type></link>.</para>
<para>
</para>
</refsect1>
<refsect1 id="libg3d-texture.details" role="details">
<title role="details.title">Details</title>
<refsect2 id="G3D-FLAG-IMG-GREYSCALE:CAPS" role="macro">
<title>G3D_FLAG_IMG_GREYSCALE</title>
<indexterm zone="G3D-FLAG-IMG-GREYSCALE:CAPS"><primary>G3D_FLAG_IMG_GREYSCALE</primary></indexterm><programlisting>#define G3D_FLAG_IMG_GREYSCALE (1L << 1)
</programlisting>
<para>
The image just uses the red channel for grey value</para>
<para>
</para></refsect2>
<refsect2 id="G3DTexEnv" role="enum">
<title>enum G3DTexEnv</title>
<indexterm zone="G3DTexEnv"><primary>G3DTexEnv</primary></indexterm><programlisting>typedef enum {
G3D_TEXENV_UNSPECIFIED = 0,
G3D_TEXENV_BLEND,
G3D_TEXENV_DECAL,
G3D_TEXENV_MODULATE,
G3D_TEXENV_REPLACE
} G3DTexEnv;
</programlisting>
<para>
Specify how the texture should interact with other material properties.</para>
<para>
</para><variablelist role="enum">
<varlistentry id="G3D-TEXENV-UNSPECIFIED:CAPS" role="constant">
<term><literal>G3D_TEXENV_UNSPECIFIED</literal></term>
<listitem><simpara> unspecified, application decides
</simpara></listitem>
</varlistentry>
<varlistentry id="G3D-TEXENV-BLEND:CAPS" role="constant">
<term><literal>G3D_TEXENV_BLEND</literal></term>
<listitem><simpara> use blending
</simpara></listitem>
</varlistentry>
<varlistentry id="G3D-TEXENV-DECAL:CAPS" role="constant">
<term><literal>G3D_TEXENV_DECAL</literal></term>
<listitem><simpara> use as decal
</simpara></listitem>
</varlistentry>
<varlistentry id="G3D-TEXENV-MODULATE:CAPS" role="constant">
<term><literal>G3D_TEXENV_MODULATE</literal></term>
<listitem><simpara> use modulate
</simpara></listitem>
</varlistentry>
<varlistentry id="G3D-TEXENV-REPLACE:CAPS" role="constant">
<term><literal>G3D_TEXENV_REPLACE</literal></term>
<listitem><simpara> replace color
</simpara></listitem>
</varlistentry>
</variablelist></refsect2>
<refsect2 id="G3DImage" role="struct">
<title>G3DImage</title>
<indexterm zone="G3DImage"><primary>G3DImage</primary></indexterm><programlisting>typedef struct {
gchar *name;
guint32 width;
guint32 height;
guint8 depth;
guint32 flags;
guint8 *pixeldata;
guint32 tex_id;
G3DTexEnv tex_env;
G3DFloat tex_scale_u;
G3DFloat tex_scale_v;
} G3DImage;
</programlisting>
<para>
Object containing a two-dimensional pixel image.</para>
<para>
</para><variablelist role="struct">
<varlistentry>
<term><link linkend="gchar">gchar</link> *<structfield>name</structfield>;</term>
<listitem><simpara> name of image
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><link linkend="guint32">guint32</link> <structfield>width</structfield>;</term>
<listitem><simpara> width of image in pixels
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><link linkend="guint32">guint32</link> <structfield>height</structfield>;</term>
<listitem><simpara> height of image in pixels
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><link linkend="guint8">guint8</link> <structfield>depth</structfield>;</term>
<listitem><simpara> depth of image in bits
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><link linkend="guint32">guint32</link> <structfield>flags</structfield>;</term>
<listitem><simpara> flags
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><link linkend="guint8">guint8</link> *<structfield>pixeldata</structfield>;</term>
<listitem><simpara> the binary image data
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><link linkend="guint32">guint32</link> <structfield>tex_id</structfield>;</term>
<listitem><simpara> the OpenGL texture id, should be unique model-wide
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><link linkend="G3DTexEnv">G3DTexEnv</link> <structfield>tex_env</structfield>;</term>
<listitem><simpara> texture environment flags
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><link linkend="G3DFloat">G3DFloat</link> <structfield>tex_scale_u</structfield>;</term>
<listitem><simpara> factor scaling texture width, should be 1.0 for most cases
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><link linkend="G3DFloat">G3DFloat</link> <structfield>tex_scale_v</structfield>;</term>
<listitem><simpara> factor scaling texture height, should be 1.0 for most cases
</simpara></listitem>
</varlistentry>
</variablelist></refsect2>
<refsect2 id="g3d-texture-load-cached" role="function">
<title>g3d_texture_load_cached ()</title>
<indexterm zone="g3d-texture-load-cached"><primary>g3d_texture_load_cached</primary></indexterm><programlisting><link linkend="G3DImage">G3DImage</link>* g3d_texture_load_cached (<link linkend="G3DContext">G3DContext</link> *context,
<link linkend="G3DModel">G3DModel</link> *model,
const <link linkend="gchar">gchar</link> *filename);</programlisting>
<para>
Loads a texture image from file and attaches it to a hash table in the
model. On a second try to load this texture it is returned from cache.</para>
<para>
</para><variablelist role="params">
<varlistentry><term><parameter>context</parameter> :</term>
<listitem><simpara> a valid context
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>model</parameter> :</term>
<listitem><simpara> a valid model
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>filename</parameter> :</term>
<listitem><simpara> the file name of the texture to load
</simpara></listitem></varlistentry>
<varlistentry><term><emphasis>Returns</emphasis> :</term><listitem><simpara> the texture image
</simpara></listitem></varlistentry>
</variablelist></refsect2>
<refsect2 id="g3d-texture-load-from-stream" role="function">
<title>g3d_texture_load_from_stream ()</title>
<indexterm zone="g3d-texture-load-from-stream"><primary>g3d_texture_load_from_stream</primary></indexterm><programlisting><link linkend="G3DImage">G3DImage</link>* g3d_texture_load_from_stream (<link linkend="G3DContext">G3DContext</link> *context,
<link linkend="G3DModel">G3DModel</link> *model,
<link linkend="G3DStream">G3DStream</link> *stream);</programlisting>
<para>
Load a texture image from a stream. The file type is determined by the
extension of the stream URI, so it should be valid. If <parameter>model</parameter> is not NULL
the texture image is cached (or retrieved from cache if available).</para>
<para>
</para><variablelist role="params">
<varlistentry><term><parameter>context</parameter> :</term>
<listitem><simpara> a valid context
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>model</parameter> :</term>
<listitem><simpara> a valid model or NULL
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>stream</parameter> :</term>
<listitem><simpara> an open stream
</simpara></listitem></varlistentry>
<varlistentry><term><emphasis>Returns</emphasis> :</term><listitem><simpara> the texture image or NULL in case of an error.
</simpara></listitem></varlistentry>
</variablelist></refsect2>
<refsect2 id="g3d-texture-load" role="function">
<title>g3d_texture_load ()</title>
<indexterm zone="g3d-texture-load"><primary>g3d_texture_load</primary></indexterm><programlisting><link linkend="G3DImage">G3DImage</link>* g3d_texture_load (<link linkend="G3DContext">G3DContext</link> *context,
const <link linkend="gchar">gchar</link> *filename);</programlisting>
<para>
Load a texture from a file. The type of file is determined by the file
extension.</para>
<para>
</para><variablelist role="params">
<varlistentry><term><parameter>context</parameter> :</term>
<listitem><simpara> a valid context
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>filename</parameter> :</term>
<listitem><simpara> the file name of the texture
</simpara></listitem></varlistentry>
<varlistentry><term><emphasis>Returns</emphasis> :</term><listitem><simpara> the texture image or NULL in case of an error.
</simpara></listitem></varlistentry>
</variablelist></refsect2>
<refsect2 id="g3d-texture-free" role="function">
<title>g3d_texture_free ()</title>
<indexterm zone="g3d-texture-free"><primary>g3d_texture_free</primary></indexterm><programlisting><link linkend="void">void</link> g3d_texture_free (<link linkend="G3DImage">G3DImage</link> *texture);</programlisting>
<para>
Frees all memory used by this texture image.</para>
<para>
</para><variablelist role="params">
<varlistentry><term><parameter>texture</parameter> :</term>
<listitem><simpara> a texture image
</simpara></listitem></varlistentry>
</variablelist></refsect2>
<refsect2 id="g3d-texture-prepare" role="function">
<title>g3d_texture_prepare ()</title>
<indexterm zone="g3d-texture-prepare"><primary>g3d_texture_prepare</primary></indexterm><programlisting><link linkend="gboolean">gboolean</link> g3d_texture_prepare (<link linkend="G3DImage">G3DImage</link> *texture);</programlisting>
<para>
Resizes the image to dimensions which are a power of 2 to be
usable as an OpenGL texture.
(FIXME: unimplemented)</para>
<para>
</para><variablelist role="params">
<varlistentry><term><parameter>texture</parameter> :</term>
<listitem><simpara> a texture image
</simpara></listitem></varlistentry>
<varlistentry><term><emphasis>Returns</emphasis> :</term><listitem><simpara> TRUE on success, FALSE else
</simpara></listitem></varlistentry>
</variablelist></refsect2>
<refsect2 id="g3d-texture-flip-y" role="function">
<title>g3d_texture_flip_y ()</title>
<indexterm zone="g3d-texture-flip-y"><primary>g3d_texture_flip_y</primary></indexterm><programlisting><link linkend="gboolean">gboolean</link> g3d_texture_flip_y (<link linkend="G3DImage">G3DImage</link> *texture);</programlisting>
<para>
Mirror the image along the x axis - all y coordinates are inverted.</para>
<para>
</para><variablelist role="params">
<varlistentry><term><parameter>texture</parameter> :</term>
<listitem><simpara> a texture image
</simpara></listitem></varlistentry>
<varlistentry><term><emphasis>Returns</emphasis> :</term><listitem><simpara> TRUE on success, FALSE on error.
</simpara></listitem></varlistentry>
</variablelist></refsect2>
<refsect2 id="g3d-texture-merge-alpha" role="function">
<title>g3d_texture_merge_alpha ()</title>
<indexterm zone="g3d-texture-merge-alpha"><primary>g3d_texture_merge_alpha</primary></indexterm><programlisting><link linkend="G3DImage">G3DImage</link>* g3d_texture_merge_alpha (<link linkend="G3DImage">G3DImage</link> *image,
<link linkend="G3DImage">G3DImage</link> *aimage);</programlisting>
<para>
Merges alpha information from <parameter>aimage</parameter> into output image. If <parameter>image</parameter> is NULL a
new image is created, else <parameter>image</parameter> is returned with alpha from <parameter>aimage</parameter>.</para>
<para>
</para><variablelist role="params">
<varlistentry><term><parameter>image</parameter> :</term>
<listitem><simpara> a texture image or NULL
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>aimage</parameter> :</term>
<listitem><simpara> an image with alpha information
</simpara></listitem></varlistentry>
<varlistentry><term><emphasis>Returns</emphasis> :</term><listitem><simpara> a texture image or NULL in case of an error.
</simpara></listitem></varlistentry>
</variablelist></refsect2>
</refsect1>
</refentry>
|
