/* * Cogl * * An object oriented GL/GLES Abstraction/Utility Layer * * Copyright (C) 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, see . * * * * Authors: * Robert Bragg */ #ifndef __COGL_MATRIX_H #define __COGL_MATRIX_H #include #include "cogl-types.h" #ifdef COGL_ENABLE_EXPERIMENTAL_API #include "cogl-quaternion.h" #endif G_BEGIN_DECLS /** * SECTION:cogl-matrix * @short_description: Fuctions for initializing and manipulating 4x4 matrices * * Matrices are used in Cogl to describe affine model-view transforms, texture * transforms, and projective transforms. This exposes a utility API that can * be used for direct manipulation of these matrices. */ /** * CoglMatrix: * * A CoglMatrix holds a 4x4 transform matrix. This is a single precision, * column-major matrix which means it is compatible with what OpenGL expects. * * A CoglMatrix can represent transforms such as, rotations, scaling, * translation, sheering, and linear projections. You can combine these * transforms by multiplying multiple matrices in the order you want them * applied. * * The transformation of a vertex (x, y, z, w) by a CoglMatrix is given by: * * |[ * x_new = xx * x + xy * y + xz * z + xw * w * y_new = yx * x + yy * y + yz * z + yw * w * z_new = zx * x + zy * y + zz * z + zw * w * w_new = wx * x + wy * y + wz * z + ww * w * ]| * * Where w is normally 1 * * You must consider the members of the CoglMatrix structure read only, * and all matrix modifications must be done via the cogl_matrix API. This * allows Cogl to annotate the matrices internally. Violation of this will give * undefined results. If you need to initialize a matrix with a constant other * than the identity matrix you can use cogl_matrix_init_from_array(). */ struct _CoglMatrix { /* column 0 */ float xx; float yx; float zx; float wx; /* column 1 */ float xy; float yy; float zy; float wy; /* column 2 */ float xz; float yz; float zz; float wz; /* column 3 */ float xw; float yw; float zw; float ww; /*< private >*/ /* Note: we may want to extend this later with private flags * and a cache of the inverse transform matrix. */ float COGL_PRIVATE (inv)[16]; unsigned long COGL_PRIVATE (type); unsigned long COGL_PRIVATE (flags); unsigned long COGL_PRIVATE (_padding3); }; /** * cogl_matrix_init_identity: * @matrix: A 4x4 transformation matrix * * Resets matrix to the identity matrix: * * |[ * .xx=1; .xy=0; .xz=0; .xw=0; * .yx=0; .yy=1; .yz=0; .yw=0; * .zx=0; .zy=0; .zz=1; .zw=0; * .wx=0; .wy=0; .wz=0; .ww=1; * ]| */ void cogl_matrix_init_identity (CoglMatrix *matrix); /** * cogl_matrix_multiply: * @result: The address of a 4x4 matrix to store the result in * @a: A 4x4 transformation matrix * @b: A 4x4 transformation matrix * * Multiplies the two supplied matrices together and stores * the resulting matrix inside @result. * * It is possible to multiply the @a matrix in-place, so * @result can be equal to @a but can't be equal to @b. */ void cogl_matrix_multiply (CoglMatrix *result, const CoglMatrix *a, const CoglMatrix *b); /** * cogl_matrix_rotate: * @matrix: A 4x4 transformation matrix * @angle: The angle you want to rotate in degrees * @x: X component of your rotation vector * @y: Y component of your rotation vector * @z: Z component of your rotation vector * * Multiplies @matrix with a rotation matrix that applies a rotation * of @angle degrees around the specified 3D vector. */ void cogl_matrix_rotate (CoglMatrix *matrix, float angle, float x, float y, float z); /** * cogl_matrix_translate: * @matrix: A 4x4 transformation matrix * @x: The X translation you want to apply * @y: The Y translation you want to apply * @z: The Z translation you want to apply * * Multiplies @matrix with a transform matrix that translates along * the X, Y and Z axis. */ void cogl_matrix_translate (CoglMatrix *matrix, float x, float y, float z); /** * cogl_matrix_scale: * @matrix: A 4x4 transformation matrix * @sx: The X scale factor * @sy: The Y scale factor * @sz: The Z scale factor * * Multiplies @matrix with a transform matrix that scales along the X, * Y and Z axis. */ void cogl_matrix_scale (CoglMatrix *matrix, float sx, float sy, float sz); /** * cogl_matrix_frustum: * @matrix: A 4x4 transformation matrix * @left: coord of left vertical clipping plane * @right: coord of right vertical clipping plane * @bottom: coord of bottom horizontal clipping plane * @top: coord of top horizontal clipping plane * @z_near: positive distance to near depth clipping plane * @z_far: positive distance to far depth clipping plane * * Multiplies @matrix by the given frustum perspective matrix. */ void cogl_matrix_frustum (CoglMatrix *matrix, float left, float right, float bottom, float top, float z_near, float z_far); /** * cogl_matrix_perspective: * @matrix: A 4x4 transformation matrix * @fov_y: A field of view angle for the Y axis * @aspect: The ratio of width to height determining the field of view angle * for the x axis. * @z_near: The distance to the near clip plane. Never pass 0 and always pass * a positive number. * @z_far: The distance to the far clip plane. (Should always be positive) * * Multiplies @matrix by the described perspective matrix * * You should be careful not to have to great a @z_far / @z_near ratio * since that will reduce the effectiveness of depth testing since there wont * be enough precision to identify the depth of objects near to each * other. */ void cogl_matrix_perspective (CoglMatrix *matrix, float fov_y, float aspect, float z_near, float z_far); /** * cogl_matrix_ortho: * @matrix: A 4x4 transformation matrix * @left: The coordinate for the left clipping plane * @right: The coordinate for the right clipping plane * @bottom: The coordinate for the bottom clipping plane * @top: The coordinate for the top clipping plane * @z_near: The coordinate for the near clipping plane (may be negative if * the plane is behind the viewer) * @z_far: The coordinate for the far clipping plane (may be negative if * the plane is behind the viewer) * * Multiplies @matrix by a parallel projection matrix. */ void cogl_matrix_ortho (CoglMatrix *matrix, float left, float right, float bottom, float top, float z_near, float z_far); #ifdef COGL_ENABLE_EXPERIMENTAL_API #define cogl_matrix_view_2d_in_frustum cogl_matrix_view_2d_in_frustum_EXP #define cogl_matrix_view_2d_in_perspective \ cogl_matrix_view_2d_in_perspective_EXP /** * cogl_matrix_view_2d_in_frustum: * @matrix: A 4x4 transformation matrix * @left: coord of left vertical clipping plane * @right: coord of right vertical clipping plane * @bottom: coord of bottom horizontal clipping plane * @top: coord of top horizontal clipping plane * @z_near: The distance to the near clip plane. Never pass 0 and always pass * a positive number. * @z_2d: The distance to the 2D plane. (Should always be positive and * be between @z_near and the z_far value that was passed to * cogl_matrix_frustum()) * @width_2d: The width of the 2D coordinate system * @height_2d: The height of the 2D coordinate system * * Multiplies @matrix by a view transform that maps the 2D coordinates * (0,0) top left and (@width_2d,@height_2d) bottom right the full viewport * size. Geometry at a depth of 0 will now lie on this 2D plane. * * Note: this doesn't multiply the matrix by any projection matrix, * but it assumes you have a perspective projection as defined by * passing the corresponding arguments to cogl_matrix_frustum(). * Toolkits such as Clutter that mix 2D and 3D drawing can use this to * create a 2D coordinate system within a 3D perspective projected * view frustum. */ void cogl_matrix_view_2d_in_frustum (CoglMatrix *matrix, float left, float right, float bottom, float top, float z_near, float z_2d, float width_2d, float height_2d); /** * cogl_matrix_view_2d_in_perspective: * @fov_y: A field of view angle for the Y axis * @aspect: The ratio of width to height determining the field of view angle * for the x axis. * @z_near: The distance to the near clip plane. Never pass 0 and always pass * a positive number. * @z_2d: The distance to the 2D plane. (Should always be positive and * be between @z_near and the z_far value that was passed to * cogl_matrix_frustum()) * @width_2d: The width of the 2D coordinate system * @height_2d: The height of the 2D coordinate system * * Multiplies @matrix by a view transform that maps the 2D coordinates * (0,0) top left and (@width_2d,@height_2d) bottom right the full viewport * size. Geometry at a depth of 0 will now lie on this 2D plane. * * Note: this doesn't multiply the matrix by any projection matrix, * but it assumes you have a perspective projection as defined by * passing the corresponding arguments to cogl_matrix_perspective(). * * Toolkits such as Clutter that mix 2D and 3D drawing can use this to * create a 2D coordinate system within a 3D perspective projected * view frustum. */ void cogl_matrix_view_2d_in_perspective (CoglMatrix *matrix, float fov_y, float aspect, float z_near, float z_2d, float width_2d, float height_2d); #endif /** * cogl_matrix_init_from_array: * @matrix: A 4x4 transformation matrix * @array: A linear array of 16 floats (column-major order) * * Initializes @matrix with the contents of @array */ void cogl_matrix_init_from_array (CoglMatrix *matrix, const float *array); /** * cogl_matrix_get_array: * @matrix: A 4x4 transformation matrix * * Casts @matrix to a float array which can be directly passed to OpenGL. * * Return value: a pointer to the float array */ G_CONST_RETURN float * cogl_matrix_get_array (const CoglMatrix *matrix); #ifdef COGL_ENABLE_EXPERIMENTAL_API /** * cogl_matrix_init_from_quaternion: * @matrix: A 4x4 transformation matrix * @quaternion: A #CoglQuaternion * * Initializes @matrix from a #CoglQuaternion rotation. * * Return value: a pointer to the float array */ void cogl_matrix_init_from_quaternion (CoglMatrix *matrix, CoglQuaternion *quaternion); #endif /** * cogl_matrix_equal: * @v1: A 4x4 transformation matrix * @v2: A 4x4 transformation matrix * * Compares two matrices to see if they represent the same * transformation. Although internally the matrices may have different * annotations associated with them and may potentially have a cached * inverse matrix these are not considered in the comparison. * * Since: 1.4 */ gboolean cogl_matrix_equal (gconstpointer v1, gconstpointer v2); /** * cogl_matrix_copy: * @matrix: A 4x4 transformation matrix you want to copy * * Allocates a new #CoglMatrix on the heap and initializes it with * the same values as @matrix. * * Returns: A newly allocated #CoglMatrix which should be freed using * cogl_matrix_free() * * Since: 1.6 */ CoglMatrix * cogl_matrix_copy (const CoglMatrix *matrix); /** * cogl_matrix_free: * @matrix: A 4x4 transformation matrix you want to free * * Frees a #CoglMatrix that was previously allocated via a call to * cogl_matrix_copy(). * * Since: 1.6 */ void cogl_matrix_free (CoglMatrix *matrix); /** * cogl_matrix_get_inverse: * @matrix: A 4x4 transformation matrix * @inverse: (out): The destination for a 4x4 inverse transformation matrix * * Gets the inverse transform of a given matrix and uses it to initialize * a new #CoglMatrix. * * Although the first parameter is annotated as const to indicate * that the transform it represents isn't modified this function may * technically save a copy of the inverse transform within the given * #CoglMatrix so that subsequent requests for the inverse transform may * avoid costly inversion calculations. * * Return value: %TRUE if the inverse was successfully calculated or %FALSE * for degenerate transformations that can't be inverted (in this case the * @inverse matrix will simply be initialized with the identity matrix) * * Since: 1.2 */ gboolean cogl_matrix_get_inverse (const CoglMatrix *matrix, CoglMatrix *inverse); /* FIXME: to be consistent with cogl_matrix_{transform,project}_points * this could be renamed to cogl_matrix_project_point for Cogl 2.0... */ /** * cogl_matrix_transform_point: * @matrix: A 4x4 transformation matrix * @x: (inout): The X component of your points position * @y: (inout): The Y component of your points position * @z: (inout): The Z component of your points position * @w: (inout): The W component of your points position * * Transforms a point whos position is given and returned as four float * components. */ void cogl_matrix_transform_point (const CoglMatrix *matrix, float *x, float *y, float *z, float *w); #ifdef COGL_ENABLE_EXPERIMENTAL_API #define cogl_matrix_transform_points cogl_matrix_transform_points_EXP #define cogl_matrix_project_points cogl_matrix_project_points_EXP /** * cogl_matrix_transform_points: * @matrix: A transformation matrix * @n_components: The number of position components for each input point. * (either 2 or 3) * @stride_in: The stride in bytes between input points. * @points_in: A pointer to the first component of the first input point. * @stride_out: The stride in bytes between output points. * @points_out: A pointer to the first component of the first output point. * @n_points: The number of points to transform. * * Transforms an array of input points and writes the result to * another array of output points. The input points can either have 2 * or 3 components each. The output points always have 3 components. * The output array can simply point to the input array to do the * transform in-place. * * If you need to transform 4 component points see * cogl_matrix_project_points(). * * Here's an example with differing input/output strides: * |[ * typedef struct { * float x,y; * guint8 r,g,b,a; * float s,t,p; * } MyInVertex; * typedef struct { * guint8 r,g,b,a; * float x,y,z; * } MyOutVertex; * MyInVertex vertices[N_VERTICES]; * MyOutVertex results[N_VERTICES]; * CoglMatrix matrix; * * my_load_vertices (vertices); * my_get_matrix (&matrix); * * cogl_matrix_transform_points (&matrix, * 2, * sizeof (MyInVertex), * &vertices[0].x, * sizeof (MyOutVertex), * &results[0].x, * N_VERTICES); * ]| * * Stability: Unstable */ void cogl_matrix_transform_points (const CoglMatrix *matrix, int n_components, size_t stride_in, const void *points_in, size_t stride_out, void *points_out, int n_points); /** * cogl_matrix_project_points: * @matrix: A projection matrix * @n_components: The number of position components for each input point. * (either 2, 3 or 4) * @stride_in: The stride in bytes between input points. * @points_in: A pointer to the first component of the first input point. * @stride_out: The stride in bytes between output points. * @points_out: A pointer to the first component of the first output point. * @n_points: The number of points to transform. * * Projects an array of input points and writes the result to another * array of output points. The input points can either have 2, 3 or 4 * components each. The output points always have 4 components (known * as homogenous coordinates). The output array can simply point to * the input array to do the transform in-place. * * Here's an example with differing input/output strides: * |[ * typedef struct { * float x,y; * guint8 r,g,b,a; * float s,t,p; * } MyInVertex; * typedef struct { * guint8 r,g,b,a; * float x,y,z; * } MyOutVertex; * MyInVertex vertices[N_VERTICES]; * MyOutVertex results[N_VERTICES]; * CoglMatrix matrix; * * my_load_vertices (vertices); * my_get_matrix (&matrix); * * cogl_matrix_project_points (&matrix, * 2, * sizeof (MyInVertex), * &vertices[0].x, * sizeof (MyOutVertex), * &results[0].x, * N_VERTICES); * ]| * * Stability: Unstable */ void cogl_matrix_project_points (const CoglMatrix *matrix, int n_components, size_t stride_in, const void *points_in, size_t stride_out, void *points_out, int n_points); #endif /* COGL_ENABLE_EXPERIMENTAL_API */ #ifdef _COGL_SUPPORTS_GTYPE_INTEGRATION #define COGL_GTYPE_TYPE_MATRIX (cogl_gtype_matrix_get_type ()) /** * cogl_gtype_matrix_get_type: * * Returns the GType for the registered "CoglMatrix" boxed type. This * can be used for example to define GObject properties that accept a * #CoglMatrix value. */ GType cogl_gtype_matrix_get_type (void); #endif /* _COGL_SUPPORTS_GTYPE_INTEGRATION */ G_END_DECLS #endif /* __COGL_MATRIX_H */