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Applied 'final patch' from bug #874

Browse Source 
* clutter/cogl/gles/cogl.c:
	* clutter/cogl/gl/cogl.c: The clip planes are now set using the
	inverse projection matrix as the modelview matrix so that they can
	be specified in screen coordinates.

	* clutter/cogl/gles/cogl-context.h (CoglContext):
	* clutter/cogl/gl/cogl-context.h (CoglContext): Added a member to
	cache the inverse projection matrix

	* clutter/clutter-fixed.h: Added a constant for converting from
	radians to degrees.

	* clutter/clutter-fixed.c (clutter_atani, clutter_atan2i): Added
	fixed-point versions of atan and atan2.

	* tests/test-clip.c: Added a test for clipping with various
	rotations and depths.

	* tests/Makefile.am (noinst_PROGRAMS): Added test-clip
This commit is contained in:
Neil Roberts 2008-06-02 12:34:10 +00:00
parent 42ed195f01
commit 8bdb98736d
9 changed files with 506 additions and 28 deletions
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24
ChangeLog
View File

@ -1,3 +1,27 @@
2008-06-02 Neil Roberts <neil@o-hand.com>
Applied 'final patch' from bug #874
* clutter/cogl/gles/cogl.c:
* clutter/cogl/gl/cogl.c: The clip planes are now set using the
inverse projection matrix as the modelview matrix so that they can
be specified in screen coordinates.
* clutter/cogl/gles/cogl-context.h (CoglContext):
* clutter/cogl/gl/cogl-context.h (CoglContext): Added a member to
cache the inverse projection matrix
* clutter/clutter-fixed.h: Added a constant for converting from
radians to degrees.
* clutter/clutter-fixed.c (clutter_atani, clutter_atan2i): Added
fixed-point versions of atan and atan2.
* tests/test-clip.c: Added a test for clipping with various
rotations and depths.
* tests/Makefile.am (noinst_PROGRAMS): Added test-clip
2008-06-02 Neil Roberts <neil@o-hand.com>
* clutter/cogl/gles/cogl-gles2-wrapper.h: The uniform numbers are

98
clutter/clutter-fixed.c
View File

@ -505,6 +505,104 @@ clutter_tani (ClutterAngle angle)
return result;
}
/* 257-value table of atan. atan_tbl[0] is atan(0.0) and atan_tbl[256]
is atan(1). The angles are radians in ClutterFixed
truncated to 16-bit (they're all less than one) */
static guint16 atan_tbl[] =
{
0x0000, 0x00FF, 0x01FF, 0x02FF, 0x03FF, 0x04FF, 0x05FF, 0x06FF,
0x07FF, 0x08FF, 0x09FE, 0x0AFE, 0x0BFD, 0x0CFD, 0x0DFC, 0x0EFB,
0x0FFA, 0x10F9, 0x11F8, 0x12F7, 0x13F5, 0x14F3, 0x15F2, 0x16F0,
0x17EE, 0x18EB, 0x19E9, 0x1AE6, 0x1BE3, 0x1CE0, 0x1DDD, 0x1ED9,
0x1FD5, 0x20D1, 0x21CD, 0x22C8, 0x23C3, 0x24BE, 0x25B9, 0x26B3,
0x27AD, 0x28A7, 0x29A1, 0x2A9A, 0x2B93, 0x2C8B, 0x2D83, 0x2E7B,
0x2F72, 0x306A, 0x3160, 0x3257, 0x334D, 0x3442, 0x3538, 0x362D,
0x3721, 0x3815, 0x3909, 0x39FC, 0x3AEF, 0x3BE2, 0x3CD4, 0x3DC5,
0x3EB6, 0x3FA7, 0x4097, 0x4187, 0x4277, 0x4365, 0x4454, 0x4542,
0x462F, 0x471C, 0x4809, 0x48F5, 0x49E0, 0x4ACB, 0x4BB6, 0x4CA0,
0x4D89, 0x4E72, 0x4F5B, 0x5043, 0x512A, 0x5211, 0x52F7, 0x53DD,
0x54C2, 0x55A7, 0x568B, 0x576F, 0x5852, 0x5934, 0x5A16, 0x5AF7,
0x5BD8, 0x5CB8, 0x5D98, 0x5E77, 0x5F55, 0x6033, 0x6110, 0x61ED,
0x62C9, 0x63A4, 0x647F, 0x6559, 0x6633, 0x670C, 0x67E4, 0x68BC,
0x6993, 0x6A6A, 0x6B40, 0x6C15, 0x6CEA, 0x6DBE, 0x6E91, 0x6F64,
0x7036, 0x7108, 0x71D9, 0x72A9, 0x7379, 0x7448, 0x7516, 0x75E4,
0x76B1, 0x777E, 0x7849, 0x7915, 0x79DF, 0x7AA9, 0x7B72, 0x7C3B,
0x7D03, 0x7DCA, 0x7E91, 0x7F57, 0x801C, 0x80E1, 0x81A5, 0x8269,
0x832B, 0x83EE, 0x84AF, 0x8570, 0x8630, 0x86F0, 0x87AF, 0x886D,
0x892A, 0x89E7, 0x8AA4, 0x8B5F, 0x8C1A, 0x8CD5, 0x8D8E, 0x8E47,
0x8F00, 0x8FB8, 0x906F, 0x9125, 0x91DB, 0x9290, 0x9345, 0x93F9,
0x94AC, 0x955F, 0x9611, 0x96C2, 0x9773, 0x9823, 0x98D2, 0x9981,
0x9A2F, 0x9ADD, 0x9B89, 0x9C36, 0x9CE1, 0x9D8C, 0x9E37, 0x9EE0,
0x9F89, 0xA032, 0xA0DA, 0xA181, 0xA228, 0xA2CE, 0xA373, 0xA418,
0xA4BC, 0xA560, 0xA602, 0xA6A5, 0xA746, 0xA7E8, 0xA888, 0xA928,
0xA9C7, 0xAA66, 0xAB04, 0xABA1, 0xAC3E, 0xACDB, 0xAD76, 0xAE11,
0xAEAC, 0xAF46, 0xAFDF, 0xB078, 0xB110, 0xB1A7, 0xB23E, 0xB2D5,
0xB36B, 0xB400, 0xB495, 0xB529, 0xB5BC, 0xB64F, 0xB6E2, 0xB773,
0xB805, 0xB895, 0xB926, 0xB9B5, 0xBA44, 0xBAD3, 0xBB61, 0xBBEE,
0xBC7B, 0xBD07, 0xBD93, 0xBE1E, 0xBEA9, 0xBF33, 0xBFBC, 0xC046,
0xC0CE, 0xC156, 0xC1DD, 0xC264, 0xC2EB, 0xC371, 0xC3F6, 0xC47B,
0xC4FF, 0xC583, 0xC606, 0xC689, 0xC70B, 0xC78D, 0xC80E, 0xC88F,
0xC90F
};
/**
* clutter_atani:
* @x: The tangent to calculate the angle for
*
* Fast fixed-point version of the arctangent function.
*
* Return value: The angle in radians represented as a #ClutterFixed
* for which the tangent is @x.
*/
ClutterFixed
clutter_atani (ClutterFixed x)
{
gboolean negative = FALSE;
ClutterFixed angle;
if (x < 0)
{
negative = TRUE;
x = -x;
}
if (x > CFX_ONE)
/* if x > 1 then atan(x) = pi/2 - atan(1/x) */
angle = CFX_PI / 2 - atan_tbl[CFX_QDIV (CFX_ONE, x) >> 8];
else
angle = atan_tbl[x >> 8];
return negative ? -angle : angle;
}
/**
* clutter_atan2i:
* @y: Numerator of tangent
* @x: Denominator of tangent
*
* Calculates the arctangent of @y / @x but uses the sign of both
* arguments to return the angle in right quadrant.
*
* Return value: The arctangent of @y / @x
*/
ClutterFixed
clutter_atan2i (ClutterFixed y, ClutterFixed x)
{
ClutterFixed angle;
if (x == 0)
angle = y >= 0 ? CFX_PI_2 : -CFX_PI_2;
else
{
angle = clutter_atani (CFX_QDIV (y, x));
if (x < 0)
angle += y >= 0 ? CFX_PI : -CFX_PI;
}
return angle;
}
ClutterFixed sqrt_tbl [] =
{
0x00000000L, 0x00010000L, 0x00016A0AL, 0x0001BB68L,

9
clutter/clutter-fixed.h
View File

@ -146,6 +146,12 @@ typedef gint32 ClutterAngle; /* angle such that 1024 == 2*PI */
* Fixed point representation of the number 60
*/
#define CFX_60 CLUTTER_INT_TO_FIXED (60)
/**
* CFX_RADIANS_TO_DEGREES:
*
* Fixed point representation of the number 180 / pi
*/
#define CFX_RADIANS_TO_DEGREES 0x394bb8
/**
* CFX_255:
*
@ -291,6 +297,9 @@ ClutterFixed clutter_sini (ClutterAngle angle);
ClutterFixed clutter_tani (ClutterAngle angle);
ClutterFixed clutter_atani (ClutterFixed x);
ClutterFixed clutter_atan2i (ClutterFixed y, ClutterFixed x);
/* convenience macros for the cos functions */
/**

3
clutter/cogl/gl/cogl-context.h
View File

@ -49,6 +49,9 @@ typedef struct
CoglFixedVec2 path_nodes_min;
CoglFixedVec2 path_nodes_max;
/* Cache of inverse projection matrix */
GLfloat inverse_projection[16];
/* Textures */
GArray *texture_handles;

137
clutter/cogl/gl/cogl.c
View File

@ -31,6 +31,7 @@
#include <string.h>
#include <gmodule.h>
#include <math.h>
#ifdef HAVE_CLUTTER_GLX
#include <dlfcn.h>
@ -385,6 +386,71 @@ cogl_color (const ClutterColor *color)
ctx->color_alpha = color->alpha;
}
static void
apply_matrix (const GLfloat *matrix, GLfloat *vertex)
{
int x, y;
GLfloat vertex_out[4] = { 0 };
for (y = 0; y < 4; y++)
for (x = 0; x < 4; x++)
vertex_out[y] += vertex[x] * matrix[y + x * 4];
memcpy (vertex, vertex_out, sizeof (vertex_out));
}
static void
project_vertex (GLfloat *modelview, GLfloat *project, GLfloat *vertex)
{
int i;
/* Apply the modelview matrix */
apply_matrix (modelview, vertex);
/* Apply the projection matrix */
apply_matrix (project, vertex);
/* Convert from homogenized coordinates */
for (i = 0; i < 4; i++)
vertex[i] /= vertex[3];
}
static void
set_clip_plane (GLint plane_num,
const GLfloat *vertex_a,
const GLfloat *vertex_b)
{
GLdouble plane[4];
GLfloat angle;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
/* Calculate the angle between the axes and the line crossing the
two points */
angle = atan2f ((vertex_b[1] - vertex_a[1]),
(vertex_b[0] - vertex_a[0])) * 180.0f / M_PI;
GE( glPushMatrix () );
/* Load the identity matrix and multiply by the reverse of the
projection matrix so we can specify the plane in screen
coordinates */
GE( glLoadIdentity () );
GE( glMultMatrixf (ctx->inverse_projection) );
/* Rotate about point a */
GE( glTranslatef (vertex_a[0], vertex_a[1], vertex_a[2]) );
/* Rotate the plane by the calculated angle so that it will connect
the two points */
GE( glRotatef (angle, 0.0f, 0.0f, 1.0f) );
GE( glTranslatef (-vertex_a[0], -vertex_a[1], -vertex_a[2]) );
plane[0] = 0.0f;
plane[1] = -1.0f;
plane[2] = 0.0f;
plane[3] = vertex_a[1];
GE( glClipPlane (plane_num, plane) );
GE( glPopMatrix () );
GE( glEnable (plane_num) );
}
void
cogl_clip_set (ClutterFixed x_offset,
ClutterFixed y_offset,
@ -393,22 +459,50 @@ cogl_clip_set (ClutterFixed x_offset,
{
if (cogl_features_available (COGL_FEATURE_FOUR_CLIP_PLANES))
{
GLdouble eqn_left[4] = { 1.0, 0, 0,
-CLUTTER_FIXED_TO_FLOAT (x_offset) };
GLdouble eqn_right[4] = { -1.0, 0, 0,
CLUTTER_FIXED_TO_FLOAT (x_offset + width) };
GLdouble eqn_top[4] = { 0, 1.0, 0, -CLUTTER_FIXED_TO_FLOAT (y_offset) };
GLdouble eqn_bottom[4] = { 0, -1.0, 0, CLUTTER_FIXED_TO_FLOAT
(y_offset + height) };
GLfloat modelview[16], projection[16];
GE( glClipPlane (GL_CLIP_PLANE0, eqn_left) );
GE( glClipPlane (GL_CLIP_PLANE1, eqn_right) );
GE( glClipPlane (GL_CLIP_PLANE2, eqn_top) );
GE( glClipPlane (GL_CLIP_PLANE3, eqn_bottom) );
GE( glEnable (GL_CLIP_PLANE0) );
GE( glEnable (GL_CLIP_PLANE1) );
GE( glEnable (GL_CLIP_PLANE2) );
GE( glEnable (GL_CLIP_PLANE3) );
GLfloat vertex_tl[4] = { CLUTTER_FIXED_TO_FLOAT (x_offset),
CLUTTER_FIXED_TO_FLOAT (y_offset),
0.0f, 1.0f };
GLfloat vertex_tr[4] = { CLUTTER_FIXED_TO_FLOAT (x_offset + width),
CLUTTER_FIXED_TO_FLOAT (y_offset),
0.0f, 1.0f };
GLfloat vertex_bl[4] = { CLUTTER_FIXED_TO_FLOAT (x_offset),
CLUTTER_FIXED_TO_FLOAT (y_offset + height),
0.0f, 1.0f };
GLfloat vertex_br[4] = { CLUTTER_FIXED_TO_FLOAT (x_offset + width),
CLUTTER_FIXED_TO_FLOAT (y_offset + height),
0.0f, 1.0f };
GE( glGetFloatv (GL_MODELVIEW_MATRIX, modelview) );
GE( glGetFloatv (GL_PROJECTION_MATRIX, projection) );
project_vertex (modelview, projection, vertex_tl);
project_vertex (modelview, projection, vertex_tr);
project_vertex (modelview, projection, vertex_bl);
project_vertex (modelview, projection, vertex_br);
/* If the order of the top and bottom lines is different from
the order of the left and right lines then the clip rect must
have been transformed so that the back is visible. We
therefore need to swap one pair of vertices otherwise all of
the planes will be the wrong way around */
if ((vertex_tl[0] < vertex_tr[0] ? 1 : 0)
!= (vertex_bl[1] < vertex_tl[1] ? 1 : 0))
{
GLfloat temp[4];
memcpy (temp, vertex_tl, sizeof (temp));
memcpy (vertex_tl, vertex_tr, sizeof (temp));
memcpy (vertex_tr, temp, sizeof (temp));
memcpy (temp, vertex_bl, sizeof (temp));
memcpy (vertex_bl, vertex_br, sizeof (temp));
memcpy (vertex_br, temp, sizeof (temp));
}
set_clip_plane (GL_CLIP_PLANE0, vertex_tl, vertex_tr);
set_clip_plane (GL_CLIP_PLANE1, vertex_tr, vertex_br);
set_clip_plane (GL_CLIP_PLANE2, vertex_br, vertex_bl);
set_clip_plane (GL_CLIP_PLANE3, vertex_bl, vertex_tl);
}
else if (cogl_features_available (COGL_FEATURE_STENCIL_BUFFER))
{
@ -467,6 +561,8 @@ cogl_perspective (ClutterFixed fovy,
GLfloat m[16];
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
memset (&m[0], 0, sizeof (m));
/*
@ -495,6 +591,17 @@ cogl_perspective (ClutterFixed fovy,
M(3,2) = -1.0F;
GE( glMultMatrixf (m) );
/* Calculate and store the inverse of the matrix */
memset (ctx->inverse_projection, 0, sizeof (GLfloat) * 16);
#define m ctx->inverse_projection
M(0, 0) = 1.0f / CLUTTER_FIXED_TO_FLOAT (x);
M(1, 1) = 1.0f / CLUTTER_FIXED_TO_FLOAT (y);
M(2, 3) = -1.0f;
M(3, 2) = 1.0f / CLUTTER_FIXED_TO_FLOAT (d);
M(3, 3) = CLUTTER_FIXED_TO_FLOAT (c) / CLUTTER_FIXED_TO_FLOAT (d);
#undef m
#undef M
}

3
clutter/cogl/gles/cogl-context.h
View File

@ -58,6 +58,9 @@ typedef struct
CoglFixedVec2 path_nodes_min;
CoglFixedVec2 path_nodes_max;
/* Cache of inverse projection matrix */
ClutterFixed inverse_projection[16];
/* Textures */
GArray *texture_handles;
CoglTextureGLVertex *texture_vertices;

130
clutter/cogl/gles/cogl.c
View File

@ -312,6 +312,74 @@ cogl_color (const ClutterColor *color)
ctx->color_alpha = color->alpha;
}
static void
apply_matrix (const ClutterFixed *matrix, ClutterFixed *vertex)
{
int x, y;
ClutterFixed vertex_out[4] = { 0 };
for (y = 0; y < 4; y++)
for (x = 0; x < 4; x++)
vertex_out[y] += CFX_QMUL (vertex[x], matrix[y + x * 4]);
memcpy (vertex, vertex_out, sizeof (vertex_out));
}
static void
project_vertex (ClutterFixed *modelview,
ClutterFixed *project,
ClutterFixed *vertex)
{
int i;
/* Apply the modelview matrix */
apply_matrix (modelview, vertex);
/* Apply the projection matrix */
apply_matrix (project, vertex);
/* Convert from homogenized coordinates */
for (i = 0; i < 4; i++)
vertex[i] = CFX_QDIV (vertex[i], vertex[3]);
}
static void
set_clip_plane (GLint plane_num,
const ClutterFixed *vertex_a,
const ClutterFixed *vertex_b)
{
GLfixed plane[4];
GLfixed angle;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
/* Calculate the angle between the axes and the line crossing the
two points */
angle = CFX_QMUL (clutter_atan2i (vertex_b[1] - vertex_a[1],
vertex_b[0] - vertex_a[0]),
CFX_RADIANS_TO_DEGREES);
GE( cogl_wrap_glPushMatrix () );
/* Load the identity matrix and multiply by the reverse of the
projection matrix so we can specify the plane in screen
coordinates */
GE( cogl_wrap_glLoadIdentity () );
GE( cogl_wrap_glMultMatrixx ((GLfixed *) ctx->inverse_projection) );
/* Rotate about point a */
GE( cogl_wrap_glTranslatex (vertex_a[0], vertex_a[1], vertex_a[2]) );
/* Rotate the plane by the calculated angle so that it will connect
the two points */
GE( cogl_wrap_glRotatex (angle, 0.0f, 0.0f, 1.0f) );
GE( cogl_wrap_glTranslatex (-vertex_a[0], -vertex_a[1], -vertex_a[2]) );
plane[0] = 0;
plane[1] = -CFX_ONE;
plane[2] = 0;
plane[3] = vertex_a[1];
GE( cogl_wrap_glClipPlanex (plane_num, plane) );
GE( cogl_wrap_glPopMatrix () );
GE( cogl_wrap_glEnable (plane_num) );
}
void
cogl_clip_set (ClutterFixed x_offset,
ClutterFixed y_offset,
@ -320,19 +388,43 @@ cogl_clip_set (ClutterFixed x_offset,
{
if (cogl_features_available (COGL_FEATURE_FOUR_CLIP_PLANES))
{
GLfixed eqn_left[4] = { CFX_ONE, 0, 0, -x_offset };
GLfixed eqn_right[4] = { -CFX_ONE, 0, 0, x_offset + width };
GLfixed eqn_top[4] = { 0, CFX_ONE, 0, -y_offset };
GLfixed eqn_bottom[4] = { 0, -CFX_ONE, 0, y_offset + height };
GLfixed modelview[16], projection[16];
GE( cogl_wrap_glClipPlanex (GL_CLIP_PLANE0, eqn_left) );
GE( cogl_wrap_glClipPlanex (GL_CLIP_PLANE1, eqn_right) );
GE( cogl_wrap_glClipPlanex (GL_CLIP_PLANE2, eqn_top) );
GE( cogl_wrap_glClipPlanex (GL_CLIP_PLANE3, eqn_bottom) );
GE( cogl_wrap_glEnable (GL_CLIP_PLANE0) );
GE( cogl_wrap_glEnable (GL_CLIP_PLANE1) );
GE( cogl_wrap_glEnable (GL_CLIP_PLANE2) );
GE( cogl_wrap_glEnable (GL_CLIP_PLANE3) );
ClutterFixed vertex_tl[4] = { x_offset, y_offset, 0, CFX_ONE };
ClutterFixed vertex_tr[4] = { x_offset + width, y_offset, 0, CFX_ONE };
ClutterFixed vertex_bl[4] = { x_offset, y_offset + height, 0, CFX_ONE };
ClutterFixed vertex_br[4] = { x_offset + width, y_offset + height,
0, CFX_ONE };
GE( cogl_wrap_glGetFixedv (GL_MODELVIEW_MATRIX, modelview) );
GE( cogl_wrap_glGetFixedv (GL_PROJECTION_MATRIX, projection) );
project_vertex (modelview, projection, vertex_tl);
project_vertex (modelview, projection, vertex_tr);
project_vertex (modelview, projection, vertex_bl);
project_vertex (modelview, projection, vertex_br);
/* If the order of the top and bottom lines is different from
the order of the left and right lines then the clip rect must
have been transformed so that the back is visible. We
therefore need to swap one pair of vertices otherwise all of
the planes will be the wrong way around */
if ((vertex_tl[0] < vertex_tr[0] ? 1 : 0)
!= (vertex_bl[1] < vertex_tl[1] ? 1 : 0))
{
ClutterFixed temp[4];
memcpy (temp, vertex_tl, sizeof (temp));
memcpy (vertex_tl, vertex_tr, sizeof (temp));
memcpy (vertex_tr, temp, sizeof (temp));
memcpy (temp, vertex_bl, sizeof (temp));
memcpy (vertex_bl, vertex_br, sizeof (temp));
memcpy (vertex_br, temp, sizeof (temp));
}
set_clip_plane (GL_CLIP_PLANE0, vertex_tl, vertex_tr);
set_clip_plane (GL_CLIP_PLANE1, vertex_tr, vertex_br);
set_clip_plane (GL_CLIP_PLANE2, vertex_br, vertex_bl);
set_clip_plane (GL_CLIP_PLANE3, vertex_bl, vertex_tl);
}
else if (cogl_features_available (COGL_FEATURE_STENCIL_BUFFER))
{
@ -391,6 +483,8 @@ cogl_perspective (ClutterFixed fovy,
GLfixed m[16];
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
memset (&m[0], 0, sizeof (m));
/*
@ -419,6 +513,18 @@ cogl_perspective (ClutterFixed fovy,
M(3,2) = 1 + ~CFX_ONE;
GE( cogl_wrap_glMultMatrixx (m) );
/* Calculate and store the inverse of the matrix */
memset (ctx->inverse_projection, 0, sizeof (ClutterFixed) * 16);
#define m ctx->inverse_projection
M(0, 0) = CFX_QDIV (CFX_ONE, x);
M(1, 1) = CFX_QDIV (CFX_ONE, y);
M(2, 3) = -CFX_ONE;
M(3, 2) = CFX_QDIV (CFX_ONE, d);
M(3, 3) = CFX_QDIV (c, d);
#undef m
#undef M
}

2
tests/Makefile.am
View File

@ -12,7 +12,7 @@ noinst_PROGRAMS = test-textures test-events test-offscreen test-scale \
test-cogl-tex-convert test-cogl-tex-foreign \
test-cogl-tex-getset test-cogl-offscreen \
test-cogl-tex-polygon test-stage-read-pixels \
test-random-text
test-random-text test-clip
if X11_TESTS
noinst_PROGRAMS += test-pixmap

128
tests/test-clip.c Normal file
View File

@ -0,0 +1,128 @@
#include <clutter/clutter.h>
#include <gdk-pixbuf/gdk-pixbuf.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>
#define TL_SCALE 5.0f
typedef struct _CallbackData CallbackData;
struct _CallbackData
{
ClutterActor *stage, *group, *rect, *hand;
};
static void
on_new_frame (ClutterTimeline *tl, int frame_num, CallbackData *data)
{
int i;
int stage_width = clutter_actor_get_width (data->stage);
int stage_height = clutter_actor_get_height (data->stage);
gdouble progress = clutter_timeline_get_progress (tl);
gdouble angle = progress * 2 * M_PI * TL_SCALE;
gdouble rotation[3];
gdouble xpos = stage_width * 0.45 * sin (angle) + stage_width / 8;
gdouble ypos = stage_height * 0.45 * sin (angle) + stage_height / 8;
gdouble zpos = stage_width * cos (angle) - stage_width / 2;
clutter_actor_set_position (data->hand, xpos, ypos);
clutter_actor_set_depth (data->hand, zpos);
clutter_actor_set_rotation (data->hand, CLUTTER_Y_AXIS,
angle / M_PI * 180.0 * 3,
clutter_actor_get_width (data->hand) / 2,
clutter_actor_get_height (data->hand) / 2,
0);
memset (rotation, 0, sizeof (rotation));
if (progress < 1 / 3.0)
rotation[2] = 360 * progress * 3;
else if (progress < 2 / 3.0)
rotation[1] = 360 * progress * 3;
else
rotation[0] = 360 * progress * 3;
for (i = 0; i < 3; i++)
{
clutter_actor_set_rotation (data->group, i,
rotation[i],
clutter_actor_get_width (data->rect) / 2,
clutter_actor_get_height (data->rect) / 2,
0);
clutter_actor_set_rotation (data->rect, i,
rotation[i],
clutter_actor_get_width (data->rect) / 2,
clutter_actor_get_height (data->rect) / 2,
0);
}
}
int
main (int argc, char **argv)
{
ClutterGeometry geom;
ClutterTimeline *tl;
ClutterColor blue = { 0x40, 0x40, 0xff, 0xff };
CallbackData data;
ClutterActor *other_hand;
int x, y;
clutter_init (&argc, &argv);
data.stage = clutter_stage_get_default ();
data.group = clutter_group_new ();
clutter_actor_get_geometry (data.stage, &geom);
geom.x = geom.width / 4;
geom.y = geom.height / 4;
geom.width /= 2;
geom.height /= 2;
clutter_actor_set_geometry (data.group, &geom);
data.rect = clutter_rectangle_new_with_color (&blue);
clutter_actor_set_geometry (data.rect, &geom);
clutter_container_add (CLUTTER_CONTAINER (data.stage), data.rect, NULL);
clutter_container_add (CLUTTER_CONTAINER (data.stage), data.group, NULL);
clutter_actor_set_clip (data.group, 0, 0, geom.width, geom.height);
data.hand = clutter_texture_new_from_file ("redhand.png", NULL);
if (data.hand == NULL)
{
g_critical ("pixbuf loading failed");
exit (1);
}
clutter_container_add (CLUTTER_CONTAINER (data.group), data.hand, NULL);
/* Add a hand at each of the four corners of the group */
for (y = 0; y < 2; y++)
for (x = 0; x < 2; x++)
{
other_hand = clutter_clone_texture_new (CLUTTER_TEXTURE (data.hand));
clutter_actor_set_anchor_point_from_gravity
(other_hand, CLUTTER_GRAVITY_CENTER);
clutter_actor_set_position (other_hand,
x * geom.width,
y * geom.height);
clutter_container_add (CLUTTER_CONTAINER (data.group),
other_hand, NULL);
}
clutter_actor_raise_top (data.hand);
tl = clutter_timeline_new (360 * TL_SCALE, 60);
clutter_timeline_start (tl);
clutter_timeline_set_loop (tl, TRUE);
g_signal_connect (tl, "new-frame", G_CALLBACK (on_new_frame), &data);
clutter_actor_show (data.stage);
clutter_main ();
return 0;
}