/* * Cogl * * An object oriented GL/GLES Abstraction/Utility Layer * * Copyright (C) 2007,2008,2009 Intel Corporation. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */ #if !defined(__COGL_H_INSIDE__) && !defined(CLUTTER_COMPILATION) #error "Only can be included directly." #endif #ifndef __COGL_MATERIAL_H__ #define __COGL_MATERIAL_H__ G_BEGIN_DECLS #include #include /** * SECTION:cogl-material * @short_description: Fuctions for creating and manipulating materials * * COGL allows creating and manipulating materials used to fill in * geometry. Materials may simply be lighting attributes (such as an * ambient and diffuse colour) or might represent one or more textures * blended together. */ /** * CoglMaterialFilter: * @COGL_MATERIAL_FILTER_NEAREST: Measuring in manhatten distance from the, * current pixel center, use the nearest texture * texel. * @COGL_MATERIAL_FILTER_LINEAR: Use the weighted average of the 4 texels * nearest the current pixel center. * @COGL_MATERIAL_FILTER_NEAREST_MIPMAP_NEAREST: Select the mimap level whose * texel size most closely matches * the current pixel, and use the * COGL_MATERIAL_FILTER_NEAREST * criterion. * @COGL_MATERIAL_FILTER_LINEAR_MIPMAP_NEAREST: Select the mimap level whose * texel size most closely matches * the current pixel, and use the * COGL_MATERIAL_FILTER_LINEAR * criterion. * @COGL_MATERIAL_FILTER_NEAREST_MIPMAP_LINEAR: Select the two mimap levels * whose texel size most closely * matches the current pixel, use * the COGL_MATERIAL_FILTER_NEAREST * criterion on each one and take * their weighted average. * @COGL_MATERIAL_FILTER_LINEAR_MIPMAP_LINEAR: Select the two mimap levels * whose texel size most closely * matches the current pixel, use * the COGL_MATERIAL_FILTER_LINEAR * criterion on each one and take * their weighted average. * * Texture filtering is used whenever the current pixel maps either to more * than one texture element (texel) or less than one. These filter enums * correspond to different strategies used to come up with a pixel color, by * possibly referring to multiple neighbouring texels and taking a weighted * average or simply using the nearest texel. */ typedef enum _CoglMaterialFilter { COGL_MATERIAL_FILTER_NEAREST = GL_NEAREST, COGL_MATERIAL_FILTER_LINEAR = GL_LINEAR, COGL_MATERIAL_FILTER_NEAREST_MIPMAP_NEAREST = GL_NEAREST_MIPMAP_NEAREST, COGL_MATERIAL_FILTER_LINEAR_MIPMAP_NEAREST = GL_LINEAR_MIPMAP_NEAREST, COGL_MATERIAL_FILTER_NEAREST_MIPMAP_LINEAR = GL_NEAREST_MIPMAP_LINEAR, COGL_MATERIAL_FILTER_LINEAR_MIPMAP_LINEAR = GL_LINEAR_MIPMAP_LINEAR } CoglMaterialFilter; /** * cogl_material_new: * * Allocates and initializes a blank white material * * Returns: a handle to the new material */ CoglHandle cogl_material_new (void); /** * cogl_material_ref: * @handle: a @CoglHandle. * * Increment the reference count for a cogl material. * * Returns: the @handle. * * Since 1.0 */ CoglHandle cogl_material_ref (CoglHandle handle); /** * cogl_material_unref: * @handle: a @CoglHandle. * * Decrement the reference count for a cogl material. * * Since 1.0 */ void cogl_material_unref (CoglHandle handle); /** * cogl_is_material: * @handle: A CoglHandle * * Gets whether the given handle references an existing material object. * * Returns: %TRUE if the handle references a #CoglMaterial, * %FALSE otherwise */ gboolean cogl_is_material (CoglHandle handle); /** * cogl_material_set_color: * @material: A CoglMaterial object * @color: The components of the color * * This is the basic color of the material, used when no lighting is enabled. * * Note that if you don't add any layers to the material then the color * will be blended unmodified with the destination; the default blend * expects premultiplied colors: for example, use (0.5, 0.0, 0.0, 0.5) for * semi-transparent red. See cogl_color_premultiply(). * * The default value is (1.0, 1.0, 1.0, 1.0) * * Since 1.0 */ void cogl_material_set_color (CoglHandle material, const CoglColor *color); /** * cogl_material_set_color4ub: * @material: A CoglMaterial object * @red: The red component * @green: The green component * @blue: The blue component * @alpha: The alpha component * * This is the basic color of the material, used when no lighting is enabled. * * The default value is (0xff, 0xff, 0xff, 0xff) * * Since 1.0 */ void cogl_material_set_color4ub (CoglHandle material, guint8 red, guint8 green, guint8 blue, guint8 alpha); /** * cogl_material_set_color4f: * @material: A CoglMaterial object * @red: The red component * @green: The green component * @blue: The blue component * @alpha: The alpha component * * This is the basic color of the material, used when no lighting is enabled. * * The default value is (1.0, 1.0, 1.0, 1.0) * * Since 1.0 */ void cogl_material_set_color4f (CoglHandle material, float red, float green, float blue, float alpha); /** * cogl_material_get_color: * @material: A CoglMaterial object * @color: The location to store the color * * This retrieves the current material color. * * Since 1.0 */ void cogl_material_get_color (CoglHandle material, CoglColor *color); /** * cogl_material_set_ambient: * @material: A CoglMaterial object * @ambient: The components of the desired ambient color * * Exposing the standard OpenGL lighting model; this function sets * the material's ambient color. The ambient color affects the overall * color of the object. Since the diffuse color will be intense when * the light hits the surface directly, the ambient will most aparent * where the light hits at a slant. * * The default value is (0.2, 0.2, 0.2, 1.0) * * Since 1.0 */ void cogl_material_set_ambient (CoglHandle material, const CoglColor *ambient); /** * cogl_material_get_ambient: * @material: A CoglMaterial object * @ambient: The location to store the ambient color * * This retrieves the materials current ambient color. * * Since 1.0 */ void cogl_material_get_ambient (CoglHandle material, CoglColor *ambient); /** * cogl_material_set_diffuse: * @material: A CoglMaterial object * @diffuse: The components of the desired diffuse color * * Exposing the standard OpenGL lighting model; this function sets * the material's diffuse color. The diffuse color is most intense * where the light hits the surface directly; perpendicular to the * surface. * * The default value is (0.8, 0.8, 0.8, 1.0) * * Since 1.0 */ void cogl_material_set_diffuse (CoglHandle material, const CoglColor *diffuse); /** * cogl_material_get_diffuse: * @material: A CoglMaterial object * @diffuse: The location to store the diffuse color * * This retrieves the materials current diffuse color. * * Since 1.0 */ void cogl_material_get_diffuse (CoglHandle material, CoglColor *diffuse); /** * cogl_material_set_ambient_and_diffuse: * @material: A CoglMaterial object * @color: The components of the desired ambient and diffuse colors * * This is a convenience for setting the diffuse and ambient color * of the material at the same time. * * The default ambient color is (0.2, 0.2, 0.2, 1.0) * The default diffuse color is (0.8, 0.8, 0.8, 1.0) * * Since 1.0 */ void cogl_material_set_ambient_and_diffuse (CoglHandle material, const CoglColor *color); /** * cogl_material_set_specular: * @material: A CoglMaterial object * @specular: The components of the desired specular color * * Exposing the standard OpenGL lighting model; this function sets * the material's specular color. The intensity of the specular color * depends on the viewport position, and is brightest along the lines * of reflection. * * The default value is (0.0, 0.0, 0.0, 1.0) * * Since 1.0 */ void cogl_material_set_specular (CoglHandle material, const CoglColor *specular); /** * cogl_material_get_specular: * @material: A CoglMaterial object * @specular: The location to store the specular color * * This retrieves the materials current specular color. * * Since 1.0 */ void cogl_material_get_specular (CoglHandle material, CoglColor *specular); /** * cogl_material_set_shininess: * @material: A CoglMaterial object * shininess: The desired shininess; range: [0.0, 1.0] * * This function sets the materials shininess which determines how * specular highlights are calculated. A higher shininess will produce * smaller brigher highlights. * * The default value is 0.0 * * Since 1.0 */ void cogl_material_set_shininess (CoglHandle material, float shininess); /** * cogl_material_get_shininess: * @material: A CoglMaterial object * * This retrieves the materials current emission color. * * Return value: The materials current shininess value * * Since 1.0 */ float cogl_material_get_shininess (CoglHandle material); /** * cogl_material_set_emission: * @material: A CoglMaterial object * @emission: The components of the desired emissive color * * Exposing the standard OpenGL lighting model; this function sets * the material's emissive color. It will look like the surface is * a light source emitting this color. * * The default value is (0.0, 0.0, 0.0, 1.0) * * Since 1.0 */ void cogl_material_set_emission (CoglHandle material, const CoglColor *emission); /** * cogl_material_get_emission: * @material: A CoglMaterial object * @emission: The location to store the emission color * * This retrieves the materials current emission color. * * Since 1.0 */ void cogl_material_get_emission (CoglHandle material, CoglColor *emission); /** * CoglMaterialAlphaFunc: * @COGL_MATERIAL_ALPHA_FUNC_NEVER: Never let the fragment through. * @COGL_MATERIAL_ALPHA_FUNC_LESS: Let the fragment through if the incoming * alpha value is less than the reference alpha * value. * @COGL_MATERIAL_ALPHA_FUNC_EQUAL: Let the fragment through if the incoming * alpha value equals the reference alpha * value. * @COGL_MATERIAL_ALPHA_FUNC_LEQUAL: Let the fragment through if the incoming * alpha value is less than or equal to the * reference alpha value. * @COGL_MATERIAL_ALPHA_FUNC_GREATER: Let the fragment through if the incoming * alpha value is greater than the reference * alpha value. * @COGL_MATERIAL_ALPHA_FUNC_NOTEQUAL: Let the fragment through if the incoming * alpha value does not equal the reference * alpha value. * @COGL_MATERIAL_ALPHA_FUNC_GEQUAL: Let the fragment through if the incoming * alpha value is greater than or equal to the * reference alpha value. * @COGL_MATERIAL_ALPHA_FUNC_ALWAYS: Always let the fragment through. * * Alpha testing happens before blending primitives with the framebuffer and * gives an opportunity to discard fragments based on a comparison with the * incoming alpha value and a reference alpha value. The #CoglMaterialAlphaFunc * determines how the comparison is done. */ typedef enum _CoglMaterialAlphaFunc { COGL_MATERIAL_ALPHA_FUNC_NEVER = GL_NEVER, COGL_MATERIAL_ALPHA_FUNC_LESS = GL_LESS, COGL_MATERIAL_ALPHA_FUNC_EQUAL = GL_EQUAL, COGL_MATERIAL_ALPHA_FUNC_LEQUAL = GL_LEQUAL, COGL_MATERIAL_ALPHA_FUNC_GREATER = GL_GREATER, COGL_MATERIAL_ALPHA_FUNC_NOTEQUAL = GL_NOTEQUAL, COGL_MATERIAL_ALPHA_FUNC_GEQUAL = GL_GEQUAL, COGL_MATERIAL_ALPHA_FUNC_ALWAYS = GL_ALWAYS } CoglMaterialAlphaFunc; /** * cogl_material_set_alpha_test_function: * @material: A CoglMaterial object * @alpha_func: A @CoglMaterialAlphaFunc constant * @alpha_reference: A reference point that the chosen alpha function uses * to compare incoming fragments to. * * Before a primitive is blended with the framebuffer, it goes through an * alpha test stage which lets you discard fragments based on the current * alpha value. This function lets you change the function used to evaluate * the alpha channel, and thus determine which fragments are discarded * and which continue on to the blending stage. * * The default is COGL_MATERIAL_ALPHA_FUNC_ALWAYS * * Since 1.0 */ void cogl_material_set_alpha_test_function (CoglHandle material, CoglMaterialAlphaFunc alpha_func, float alpha_reference); /** * cogl_material_set_blend: * @material: A CoglMaterial object * @blend_string: A Cogl blend string * describing the desired blend function. * @error: A GError that may report lack of driver support if you give * separate blend string statements for the alpha channel and RGB * channels since some drivers or backends such as GLES 1.1 dont * support this. May be %NULL, in which case a warning will be * printed out if an error is encountered. * * If not already familiar; please refer * here for an overview of what blend * strings are and there syntax. * * Blending occurs after the alpha test function, and combines fragments with * the framebuffer. * Currently the only blend function Cogl exposes is ADD(). So any valid * blend statements will be of the form: * * * <channel-mask>=ADD(SRC_COLOR*(<factor>), DST_COLOR*(<factor>)) * * * NOTE: The brackets around blend factors are currently not optional! * * This is the list of source-names usable as blend factors: * * SRC_COLOR: The color of the in comming fragment * DST_COLOR: The color of the framebuffer * * CONSTANT: The constant set via cogl_material_set_blend_constant() * * The source names can be used according to the * color-source and factor syntax, * so for example "(1-SRC_COLOR[A])" would be a valid factor, as would * "(CONSTANT[RGB])" * * These can also be used as factors: * * 0: (0, 0, 0, 0) * 1: (1, 1, 1, 1) * SRC_ALPHA_SATURATE_FACTOR: (f,f,f,1) * where f=MIN(SRC_COLOR[A],1-DST_COLOR[A]) * * * Remember; all color components are normalized to the range [0, 1] before * computing the result of blending. * *
* Examples * Blend a non-premultiplied source over a destination with * premultiplied alpha: * * "RGB = ADD(SRC_COLOR*(SRC_COLOR[A]), DST_COLOR*(1-SRC_COLOR[A]))" * "A = ADD(SRC_COLOR, DST_COLOR*(1-SRC_COLOR[A]))" * * Blend a premultiplied source over a destination with premultiplied alpha: * * "RGBA = ADD(SRC_COLOR, DST_COLOR*(1-SRC_COLOR[A]))" * *
* * The default blend string is: * "RGBA = ADD (SRC_COLOR, DST_COLOR*(1-SRC_COLOR[A]))" * That gives normal alpha-blending when the calculated color for the material * is in premultiplied form. * * Returns: TRUE if the blend string was successfully parsed, and the described * blending is supported by the underlying driver/hardware. If there * was an error, it returns FALSE. * * Since: 1.0 */ gboolean cogl_material_set_blend (CoglHandle material, const char *blend_string, GError **error); /** * cogl_material_set_blend_constant: * @material: A CoglMaterial object * @constant_color: The constant color you want * * When blending is setup to reference a CONSTANT blend factor then * blending will depend on the constant set with this function. * * Since: 1.0 */ void cogl_material_set_blend_constant (CoglHandle material, CoglColor *constant_color); /** * cogl_material_set_layer: * @material: A CoglMaterial object * * In addition to the standard OpenGL lighting model a Cogl material may have * one or more layers comprised of textures that can be blended together in * order, with a number of different texture combine modes. This function * defines a new texture layer. * * The index values of multiple layers do not have to be consecutive; it is * only their relative order that is important. * * XXX: In the future, we may define other types of material layers, such * as purely GLSL based layers. * * Since 1.0 */ void cogl_material_set_layer (CoglHandle material, int layer_index, CoglHandle texture); /** * cogl_material_add_texture: * @material: A CoglMaterial object * @layer_index: Specifies the layer you want to remove * * This function removes a layer from your material */ void cogl_material_remove_layer (CoglHandle material, gint layer_index); /** * cogl_material_set_layer_combine: * @material: A CoglMaterial object * @layer_index: Specifies the layer you want define a combine function for * @blend_string: A Cogl blend string * describing the desired texture combine function. * @error: A GError that may report parse errors or lack of GPU/driver support. * May be %NULL, in which case a warning will be printed out if an * error is encountered. * * If not already familiar; you can refer * here for an overview of what blend * strings are and there syntax. * * These are all the functions available for texture combining: * * REPLACE(arg0) = arg0 * MODULATE(arg0, arg1) = arg0 x arg1 * ADD(arg0, arg1) = arg0 + arg1 * ADD_SIGNED(arg0, arg1) = arg0 + arg1 - 0.5 * INTERPOLATE(arg0, arg1, arg2) = * arg0 x arg2 + arg1 x (1 - arg2) * SUBTRACT(arg0, arg1) = arg0 - arg1 * * DOT3_RGB(arg0, arg1) = * * 4 x ((arg0[R] - 0.5)) * (arg1[R] - 0.5) + * (arg0[G] - 0.5)) * (arg1[G] - 0.5) + * (arg0[B] - 0.5)) * (arg1[B] - 0.5)) * * * DOT3_RGBA(arg0, arg1) = * * 4 x ((arg0[R] - 0.5)) * (arg1[R] - 0.5) + * (arg0[G] - 0.5)) * (arg1[G] - 0.5) + * (arg0[B] - 0.5)) * (arg1[B] - 0.5)) * * * * * Refer to the * color-source syntax for * describing the arguments. The valid source names for texture combining * are: * * * TEXTURE: Use the color from the current texture layer * * * TEXTURE_0, TEXTURE_1, etc: Use the color from the specified texture layer * * * CONSTANT: Use the color from the constant given with * cogl_material_set_layer_constant() * * * PRIMARY: Use the color of the material as set with cogl_material_set_color() * * * PREVIOUS: Either use the texture color from the previous layer, or if this * is layer 0, use the color of the material as set with * cogl_material_set_color() * * *
* Example * This is effectively what the default blending is: * * "RGBA = MODULATE (PREVIOUS, TEXTURE)" * * This could be used to cross-fade between two images, using the alpha * component of a constant as the interpolator. The constant color * is given by calling cogl_material_set_layer_constant. * * RGBA = INTERPOLATE (PREVIOUS, TEXTURE, CONSTANT[A]) * *
* Note: you can't give a multiplication factor for arguments as you can * with blending. * * Returns: TRUE if the blend string was successfully parsed, and the described * texture combining is supported by the underlying driver/hardware. * If there was an error, it returns FALSE. * * Since: 1.0 */ gboolean cogl_material_set_layer_combine (CoglHandle material, gint layer_index, const char *blend_string, GError **error); /** * cogl_material_set_layer_combine_constant: * @material: A CoglMaterial object * @layer_index: Specifies the layer you want to specify a constant used * for texture combining * @color_constant: The constant color you want * * When you are using the 'CONSTANT' color source in a layer combine * description then you can use this function to define its value. * * Since 1.0 */ void cogl_material_set_layer_combine_constant (CoglHandle material, int layer_index, CoglColor *constant); /** * cogl_material_set_layer_matrix: * @material: A CoglMaterial object * * This function lets you set a matrix that can be used to e.g. translate * and rotate a single layer of a material used to fill your geometry. */ void cogl_material_set_layer_matrix (CoglHandle material, int layer_index, CoglMatrix *matrix); /** * cogl_material_get_layers: * @material: A CoglMaterial object * * This function lets you access a materials internal list of layers * for iteration. * * Returns: A list of #CoglHandle's that can be passed to the * cogl_material_layer_* functions. */ const GList *cogl_material_get_layers (CoglHandle material_handle); /** * CoglMaterialLayerType: * @COGL_MATERIAL_LAYER_TYPE_TEXTURE: The layer represents a * Cogl texture * * Available types of layers for a #CoglMaterial. This enumeration * might be expanded in later versions. * * Since: 1.0 */ typedef enum _CoglMaterialLayerType { COGL_MATERIAL_LAYER_TYPE_TEXTURE } CoglMaterialLayerType; /** * cogl_material_layer_get_type: * @layer_handle: A Cogl material layer handle * * Currently there is only one type of layer defined: * COGL_MATERIAL_LAYER_TYPE_TEXTURE, but considering we may add purely GLSL * based layers in the future, you should write code that checks the type * first. */ CoglMaterialLayerType cogl_material_layer_get_type (CoglHandle layer_handle); /** * cogl_material_layer_get_texture: * @layer_handle: A CoglMaterialLayer handle * * This lets you extract a CoglTexture handle for a specific layer. * * Note: In the future, we may support purely GLSL based layers which will * likely return COGL_INVALID_HANDLE if you try to get the texture. * Considering this, you can call cogl_material_layer_get_type first, * to check it is of type COGL_MATERIAL_LAYER_TYPE_TEXTURE. * * Note: It is possible for a layer object of type * COGL_MATERIAL_LAYER_TYPE_TEXTURE to be realized before a texture * object has been associated with the layer. For example this happens * if you setup layer combining for a given layer index before calling * cogl_material_set_layer for that index. * * Returns: A CoglHandle to the layers texture object or COGL_INVALID_HANDLE * if a texture has not been set yet. */ CoglHandle cogl_material_layer_get_texture (CoglHandle layer_handle); /** * cogl_material_layer_get_min_filter: * @layer_handle: a #CoglHandle for a material layer. * * Query the currently set downscaling filter for a cogl material layer. * * Returns: the current downscaling filter for a cogl material layer. */ CoglMaterialFilter cogl_material_layer_get_min_filter (CoglHandle layer_handle); /** * cogl_material_layer_get_mag_filter: * @layer_handle: a #CoglHandle for a material layer. * * Query the currently set downscaling filter for a cogl material layer. * * Returns: the current downscaling filter for a cogl material layer. */ CoglMaterialFilter cogl_material_layer_get_mag_filter (CoglHandle layer_handle); /** * cogl_material_set_layer_filters: * @handle: a #CoglHandle to a material. * @layer_index: the layer number to change. * @min_filter: the filter used when scaling a texture down. * @mag_filter: the filter used when magnifying a texture. * * Changes the decimation and interpolation filters used when a texture is * drawn at other scales than 100%. */ void cogl_material_set_layer_filters (CoglHandle handle, gint layer_index, CoglMaterialFilter min_filter, CoglMaterialFilter mag_filter); G_END_DECLS #endif /* __COGL_MATERIAL_H__ */