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mutter/cogl/cogl-primitives.c
Emmanuele Bassi de5c84c453 cogl: Const-ify vertices in cogl_polygon() 
The CoglTextureVertex array passed to cogl_polygon() is a pure
in-argument and should be const-ified.

http://bugzilla.openedhand.com/show_bug.cgi?id=1917
2010-01-04 11:43:00 +00:00

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/*
* 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "cogl.h"
#include "cogl-internal.h"
#include "cogl-context.h"
#include "cogl-journal-private.h"
#include "cogl-texture-private.h"
#include "cogl-material-private.h"
#include "cogl-vertex-buffer-private.h"
#include "cogl-framebuffer-private.h"
#include <string.h>
#include <math.h>
#define _COGL_MAX_BEZ_RECURSE_DEPTH 16
#ifdef HAVE_COGL_GL
#define glClientActiveTexture ctx->drv.pf_glClientActiveTexture
#endif
typedef struct _TextureSlicedQuadState
{
CoglHandle material;
float tex_virtual_origin_x;
float tex_virtual_origin_y;
float quad_origin_x;
float quad_origin_y;
float v_to_q_scale_x;
float v_to_q_scale_y;
float quad_len_x;
float quad_len_y;
gboolean flipped_x;
gboolean flipped_y;
} TextureSlicedQuadState;
typedef struct _TextureSlicedPolygonState
{
const CoglTextureVertex *vertices;
int n_vertices;
int stride;
} TextureSlicedPolygonState;
static void
log_quad_sub_textures_cb (CoglHandle texture_handle,
GLuint gl_handle,
GLenum gl_target,
float *subtexture_coords,
float *virtual_coords,
void *user_data)
{
TextureSlicedQuadState *state = user_data;
float quad_coords[4];
#define TEX_VIRTUAL_TO_QUAD(V, Q, AXIS) \
do { \
Q = V - state->tex_virtual_origin_##AXIS; \
Q *= state->v_to_q_scale_##AXIS; \
if (state->flipped_##AXIS) \
Q = state->quad_len_##AXIS - Q; \
Q += state->quad_origin_##AXIS; \
} while (0);
TEX_VIRTUAL_TO_QUAD (virtual_coords[0], quad_coords[0], x);
TEX_VIRTUAL_TO_QUAD (virtual_coords[1], quad_coords[1], y);
TEX_VIRTUAL_TO_QUAD (virtual_coords[2], quad_coords[2], x);
TEX_VIRTUAL_TO_QUAD (virtual_coords[3], quad_coords[3], y);
#undef TEX_VIRTUAL_TO_QUAD
COGL_NOTE (DRAW,
"~~~~~ slice\n"
"qx1: %f\t"
"qy1: %f\n"
"qx2: %f\t"
"qy2: %f\n"
"tx1: %f\t"
"ty1: %f\n"
"tx2: %f\t"
"ty2: %f\n",
quad_coords[0], quad_coords[1],
quad_coords[2], quad_coords[3],
subtexture_coords[0], subtexture_coords[1],
subtexture_coords[2], subtexture_coords[3]);
/* FIXME: when the wrap mode becomes part of the material we need to
* be able to override the wrap mode when logging a quad. */
_cogl_journal_log_quad (quad_coords[0],
quad_coords[1],
quad_coords[2],
quad_coords[3],
state->material,
1, /* one layer */
0, /* don't need to use fallbacks */
gl_handle, /* replace the layer0 texture */
subtexture_coords,
4);
}
/* This path doesn't currently support multitexturing but is used for
* CoglTextures that don't support repeating using the GPU so we need to
* manually emit extra geometry to fake the repeating. This includes:
*
* - CoglTexture2DSliced: when made of > 1 slice or if the users given
* texture coordinates require repeating,
* - CoglTexture2DAtlas: if the users given texture coordinates require
* repeating,
* - CoglTextureRectangle: if the users given texture coordinates require
* repeating,
* - CoglTexturePixmap: if the users given texture coordinates require
* repeating
*/
/* TODO: support multitexturing */
static void
_cogl_texture_quad_multiple_primitives (CoglHandle tex_handle,
CoglHandle material,
float x_1,
float y_1,
float x_2,
float y_2,
float tx_1,
float ty_1,
float tx_2,
float ty_2)
{
TextureSlicedQuadState state;
gboolean tex_virtual_flipped_x;
gboolean tex_virtual_flipped_y;
gboolean quad_flipped_x;
gboolean quad_flipped_y;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
COGL_NOTE (DRAW, "Drawing Tex Quad (Multi-Prim Mode)");
/* We can't use hardware repeat so we need to set clamp to edge
otherwise it might pull in edge pixels from the other side */
/* FIXME: wrap modes should be part of the material! */
_cogl_texture_set_wrap_mode_parameter (tex_handle, GL_CLAMP_TO_EDGE);
state.material = material;
/* Get together the data we need to transform the virtual texture
* coordinates of each slice into quad coordinates...
*
* NB: We need to consider that the quad coordinates and the texture
* coordinates may be inverted along the x or y axis, and must preserve the
* inversions when we emit the final geometry.
*/
tex_virtual_flipped_x = (tx_1 > tx_2) ? TRUE : FALSE;
tex_virtual_flipped_y = (ty_1 > ty_2) ? TRUE : FALSE;
state.tex_virtual_origin_x = tex_virtual_flipped_x ? tx_2 : tx_1;
state.tex_virtual_origin_y = tex_virtual_flipped_y ? ty_2 : ty_1;
quad_flipped_x = (x_1 > x_2) ? TRUE : FALSE;
quad_flipped_y = (y_1 > y_2) ? TRUE : FALSE;
state.quad_origin_x = quad_flipped_x ? x_2 : x_1;
state.quad_origin_y = quad_flipped_y ? y_2 : y_1;
/* flatten the two forms of coordinate inversion into one... */
state.flipped_x = tex_virtual_flipped_x ^ quad_flipped_x;
state.flipped_y = tex_virtual_flipped_y ^ quad_flipped_y;
/* We use the _len_AXIS naming here instead of _width and _height because
* log_quad_slice_cb uses a macro with symbol concatenation to handle both
* axis, so this is more convenient... */
state.quad_len_x = fabs (x_2 - x_1);
state.quad_len_y = fabs (y_2 - y_1);
state.v_to_q_scale_x = fabs (state.quad_len_x / (tx_2 - tx_1));
state.v_to_q_scale_y = fabs (state.quad_len_y / (ty_2 - ty_1));
_cogl_texture_foreach_sub_texture_in_region (tex_handle,
tx_1, ty_1, tx_2, ty_2,
log_quad_sub_textures_cb,
&state);
}
/* This path supports multitexturing but only when each of the layers is
* handled with a single GL texture. Also if repeating is necessary then
* _cogl_texture_can_hardware_repeat() must return TRUE.
* This includes layers made from:
*
* - CoglTexture2DSliced: if only comprised of a single slice with optional
* waste, assuming the users given texture coordinates don't require
* repeating.
* - CoglTexture{1D,2D,3D}: always.
* - CoglTexture2DAtlas: assuming the users given texture coordinates don't
* require repeating.
* - CoglTextureRectangle: assuming the users given texture coordinates don't
* require repeating.
* - CoglTexturePixmap: assuming the users given texture coordinates don't
* require repeating.
*/
static gboolean
_cogl_multitexture_quad_single_primitive (float x_1,
float y_1,
float x_2,
float y_2,
CoglHandle material,
guint32 fallback_layers,
const float *user_tex_coords,
int user_tex_coords_len)
{
int n_layers = cogl_material_get_n_layers (material);
float *final_tex_coords = alloca (sizeof (float) * 4 * n_layers);
const GList *layers;
GList *tmp;
int i;
_COGL_GET_CONTEXT (ctx, FALSE);
/*
* Validate the texture coordinates for this rectangle.
*/
layers = cogl_material_get_layers (material);
for (tmp = (GList *)layers, i = 0; tmp != NULL; tmp = tmp->next, i++)
{
CoglHandle layer = (CoglHandle)tmp->data;
CoglHandle tex_handle;
const float *in_tex_coords;
float *out_tex_coords;
float default_tex_coords[4] = {0.0, 0.0, 1.0, 1.0};
tex_handle = cogl_material_layer_get_texture (layer);
/* COGL_INVALID_HANDLE textures are handled by
* _cogl_material_flush_gl_state */
if (tex_handle == COGL_INVALID_HANDLE)
continue;
in_tex_coords = &user_tex_coords[i * 4];
out_tex_coords = &final_tex_coords[i * 4];
/* If the texture has waste or we are using GL_TEXTURE_RECT we
* can't handle texture repeating so we check that the texture
* coords lie in the range [0,1].
*
* NB: We already know that the texture isn't sliced so we can assume
* that the default coords (0,0) and (1,1) would only reference a single
* GL texture.
*
* NB: We already know that no texture matrix is being used if the
* texture doesn't support hardware repeat.
*/
if (!_cogl_texture_can_hardware_repeat (tex_handle)
&& i < user_tex_coords_len / 4
&& (in_tex_coords[0] < 0 || in_tex_coords[0] > 1.0
|| in_tex_coords[1] < 0 || in_tex_coords[1] > 1.0
|| in_tex_coords[2] < 0 || in_tex_coords[2] > 1.0
|| in_tex_coords[3] < 0 || in_tex_coords[3] > 1.0))
{
if (i == 0)
{
if (n_layers > 1)
{
static gboolean warning_seen = FALSE;
if (!warning_seen)
g_warning ("Skipping layers 1..n of your material since "
"the first layer doesn't support hardware "
"repeat (e.g. because of waste or use of "
"GL_TEXTURE_RECTANGLE_ARB) and you supplied "
"texture coordinates outside the range [0,1]."
"Falling back to software repeat assuming "
"layer 0 is the most important one keep");
warning_seen = TRUE;
}
return FALSE;
}
else
{
static gboolean warning_seen = FALSE;
if (!warning_seen)
g_warning ("Skipping layer %d of your material "
"since you have supplied texture coords "
"outside the range [0,1] but the texture "
"doesn't support hardware repeat (e.g. "
"because of waste or use of "
"GL_TEXTURE_RECTANGLE_ARB). This isn't "
"supported with multi-texturing.", i);
warning_seen = TRUE;
/* NB: marking for fallback will replace the layer with
* a default transparent texture */
fallback_layers |= (1 << i);
}
}
/*
* Setup the texture unit...
*/
/* NB: The user might not have supplied texture coordinates for all
* layers... */
if (i < (user_tex_coords_len / 4))
{
GLenum wrap_mode;
/* If the texture coords are all in the range [0,1] then we want to
clamp the coords to the edge otherwise it can pull in edge pixels
from the wrong side when scaled */
if (in_tex_coords[0] >= 0 && in_tex_coords[0] <= 1.0
&& in_tex_coords[1] >= 0 && in_tex_coords[1] <= 1.0
&& in_tex_coords[2] >= 0 && in_tex_coords[2] <= 1.0
&& in_tex_coords[3] >= 0 && in_tex_coords[3] <= 1.0)
wrap_mode = GL_CLAMP_TO_EDGE;
else
wrap_mode = GL_REPEAT;
memcpy (out_tex_coords, in_tex_coords, sizeof (GLfloat) * 4);
_cogl_texture_set_wrap_mode_parameter (tex_handle, wrap_mode);
}
else
{
memcpy (out_tex_coords, default_tex_coords, sizeof (GLfloat) * 4);
_cogl_texture_set_wrap_mode_parameter (tex_handle, GL_CLAMP_TO_EDGE);
}
_cogl_texture_transform_coords_to_gl (tex_handle,
&out_tex_coords[0],
&out_tex_coords[1]);
_cogl_texture_transform_coords_to_gl (tex_handle,
&out_tex_coords[2],
&out_tex_coords[3]);
}
_cogl_journal_log_quad (x_1,
y_1,
x_2,
y_2,
material,
n_layers,
fallback_layers,
0, /* don't replace the layer0 texture */
final_tex_coords,
n_layers * 4);
return TRUE;
}
struct _CoglMutiTexturedRect
{
float x_1;
float y_1;
float x_2;
float y_2;
const float *tex_coords;
gint tex_coords_len;
};
static void
_cogl_rectangles_with_multitexture_coords (
struct _CoglMutiTexturedRect *rects,
gint n_rects)
{
CoglHandle material;
const GList *layers;
int n_layers;
const GList *tmp;
guint32 fallback_layers = 0;
gboolean all_use_sliced_quad_fallback = FALSE;
int i;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
material = ctx->source_material;
layers = cogl_material_get_layers (material);
n_layers = cogl_material_get_n_layers (material);
/*
* Validate all the layers of the current source material...
*/
for (tmp = layers, i = 0; tmp != NULL; tmp = tmp->next, i++)
{
CoglHandle layer = tmp->data;
CoglHandle tex_handle;
gulong flags;
if (cogl_material_layer_get_type (layer)
!= COGL_MATERIAL_LAYER_TYPE_TEXTURE)
continue;
tex_handle = cogl_material_layer_get_texture (layer);
/* COGL_INVALID_HANDLE textures are handled by
* _cogl_material_flush_gl_state */
if (tex_handle == COGL_INVALID_HANDLE)
continue;
/* XXX:
* For now, if the first layer is sliced then all other layers are
* ignored since we currently don't support multi-texturing with
* sliced textures. If the first layer is not sliced then any other
* layers found to be sliced will be skipped. (with a warning)
*
* TODO: Add support for multi-texturing rectangles with sliced
* textures if no texture matrices are in use.
*/
if (cogl_texture_is_sliced (tex_handle))
{
if (i == 0)
{
fallback_layers = ~1; /* fallback all except the first layer */
all_use_sliced_quad_fallback = TRUE;
if (tmp->next)
{
static gboolean warning_seen = FALSE;
if (!warning_seen)
g_warning ("Skipping layers 1..n of your material since "
"the first layer is sliced. We don't currently "
"support any multi-texturing with sliced "
"textures but assume layer 0 is the most "
"important to keep");
warning_seen = TRUE;
}
break;
}
else
{
static gboolean warning_seen = FALSE;
if (!warning_seen)
g_warning ("Skipping layer %d of your material consisting of "
"a sliced texture (unsuported for multi texturing)",
i);
warning_seen = TRUE;
/* NB: marking for fallback will replace the layer with
* a default transparent texture */
fallback_layers |= (1 << i);
continue;
}
}
/* If the texture can't be repeated with the GPU (e.g. because it has
* waste or if using GL_TEXTURE_RECTANGLE_ARB) then we don't support
* multi texturing since we don't know if the result will end up trying
* to texture from the waste area. */
flags = _cogl_material_layer_get_flags (layer);
if (flags & COGL_MATERIAL_LAYER_FLAG_HAS_USER_MATRIX
&& !_cogl_texture_can_hardware_repeat (tex_handle))
{
static gboolean warning_seen = FALSE;
if (!warning_seen)
g_warning ("Skipping layer %d of your material since a custom "
"texture matrix was given for a texture that can't be "
"repeated using the GPU and the result may try to "
"sample beyond the bounds of the texture ",
i);
warning_seen = TRUE;
/* NB: marking for fallback will replace the layer with
* a default transparent texture */
fallback_layers |= (1 << i);
continue;
}
}
/*
* Emit geometry for each of the rectangles...
*/
for (i = 0; i < n_rects; i++)
{
CoglHandle first_layer, tex_handle;
const float default_tex_coords[4] = {0.0, 0.0, 1.0, 1.0};
const float *tex_coords;
if (!all_use_sliced_quad_fallback)
{
gboolean success =
_cogl_multitexture_quad_single_primitive (rects[i].x_1,
rects[i].y_1,
rects[i].x_2,
rects[i].y_2,
material,
fallback_layers,
rects[i].tex_coords,
rects[i].tex_coords_len);
/* NB: If _cogl_multitexture_quad_single_primitive fails then it
* means the user tried to use texture repeat with a texture that
* can't be repeated by the GPU (e.g. due to waste or use of
* GL_TEXTURE_RECTANGLE_ARB) */
if (success)
continue;
}
/* If multitexturing failed or we are drawing with a sliced texture
* then we only support a single layer so we pluck out the texture
* from the first material layer... */
first_layer = layers->data;
tex_handle = cogl_material_layer_get_texture (first_layer);
if (rects[i].tex_coords)
tex_coords = rects[i].tex_coords;
else
tex_coords = default_tex_coords;
_cogl_texture_quad_multiple_primitives (tex_handle,
material,
rects[i].x_1, rects[i].y_1,
rects[i].x_2, rects[i].y_2,
tex_coords[0],
tex_coords[1],
tex_coords[2],
tex_coords[3]);
}
#if 0
/* XXX: The current journal doesn't handle changes to the model view matrix
* so for now we force a flush at the end of every primitive. */
_cogl_journal_flush ();
#endif
}
void
cogl_rectangles (const float *verts,
guint n_rects)
{
struct _CoglMutiTexturedRect *rects;
int i;
rects = g_alloca (n_rects * sizeof (struct _CoglMutiTexturedRect));
for (i = 0; i < n_rects; i++)
{
rects[i].x_1 = verts[i * 4];
rects[i].y_1 = verts[i * 4 + 1];
rects[i].x_2 = verts[i * 4 + 2];
rects[i].y_2 = verts[i * 4 + 3];
rects[i].tex_coords = NULL;
rects[i].tex_coords_len = 0;
}
_cogl_rectangles_with_multitexture_coords (rects, n_rects);
}
void
cogl_rectangles_with_texture_coords (const float *verts,
guint n_rects)
{
struct _CoglMutiTexturedRect *rects;
int i;
rects = g_alloca (n_rects * sizeof (struct _CoglMutiTexturedRect));
for (i = 0; i < n_rects; i++)
{
rects[i].x_1 = verts[i * 8];
rects[i].y_1 = verts[i * 8 + 1];
rects[i].x_2 = verts[i * 8 + 2];
rects[i].y_2 = verts[i * 8 + 3];
/* FIXME: rect should be defined to have a const float *geom;
* instead, to avoid this copy
* rect[i].geom = &verts[n_rects * 8]; */
rects[i].tex_coords = &verts[i * 8 + 4];
rects[i].tex_coords_len = 4;
}
_cogl_rectangles_with_multitexture_coords (rects, n_rects);
}
void
cogl_rectangle_with_texture_coords (float x_1,
float y_1,
float x_2,
float y_2,
float tx_1,
float ty_1,
float tx_2,
float ty_2)
{
float verts[8];
verts[0] = x_1;
verts[1] = y_1;
verts[2] = x_2;
verts[3] = y_2;
verts[4] = tx_1;
verts[5] = ty_1;
verts[6] = tx_2;
verts[7] = ty_2;
cogl_rectangles_with_texture_coords (verts, 1);
}
void
cogl_rectangle_with_multitexture_coords (float x_1,
float y_1,
float x_2,
float y_2,
const float *user_tex_coords,
gint user_tex_coords_len)
{
struct _CoglMutiTexturedRect rect;
rect.x_1 = x_1;
rect.y_1 = y_1;
rect.x_2 = x_2;
rect.y_2 = y_2;
rect.tex_coords = user_tex_coords;
rect.tex_coords_len = user_tex_coords_len;
_cogl_rectangles_with_multitexture_coords (&rect, 1);
}
void
cogl_rectangle (float x_1,
float y_1,
float x_2,
float y_2)
{
cogl_rectangle_with_multitexture_coords (x_1, y_1,
x_2, y_2,
NULL, 0);
}
void
draw_polygon_sub_texture_cb (CoglHandle tex_handle,
GLuint gl_handle,
GLenum gl_target,
float *subtexture_coords,
float *virtual_coords,
void *user_data)
{
TextureSlicedPolygonState *state = user_data;
GLfloat *v;
int i;
CoglMaterialFlushOptions options;
float slice_origin_x;
float slice_origin_y;
float virtual_origin_x;
float virtual_origin_y;
float v_to_s_scale_x;
float v_to_s_scale_y;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
slice_origin_x = subtexture_coords[0];
slice_origin_y = subtexture_coords[1];
virtual_origin_x = virtual_coords[0];
virtual_origin_y = virtual_coords[1];
v_to_s_scale_x = ((virtual_coords[2] - virtual_coords[0]) /
(subtexture_coords[2] - subtexture_coords[0]));
v_to_s_scale_y = ((virtual_coords[3] - virtual_coords[1]) /
(subtexture_coords[3] - subtexture_coords[1]));
/* Convert the vertices into an array of GLfloats ready to pass to
* OpenGL */
v = (GLfloat *)ctx->logged_vertices->data;
for (i = 0; i < state->n_vertices; i++)
{
/* NB: layout = [X,Y,Z,TX,TY,R,G,B,A,...] */
GLfloat *t = v + 3;
t[0] = ((state->vertices[i].tx - virtual_origin_x) * v_to_s_scale_x
+ slice_origin_x);
t[1] = ((state->vertices[i].ty - virtual_origin_y) * v_to_s_scale_y
+ slice_origin_y);
v += state->stride;
}
options.flags =
COGL_MATERIAL_FLUSH_DISABLE_MASK |
COGL_MATERIAL_FLUSH_LAYER0_OVERRIDE;
/* disable all except the first layer */
options.disable_layers = (guint32)~1;
options.layer0_override_texture = gl_handle;
_cogl_material_flush_gl_state (ctx->source_material, &options);
GE (glDrawArrays (GL_TRIANGLE_FAN, 0, state->n_vertices));
}
/* handles 2d-sliced textures with > 1 slice */
static void
_cogl_texture_polygon_multiple_primitives (const CoglTextureVertex *vertices,
unsigned int n_vertices,
unsigned int stride,
gboolean use_color)
{
const GList *layers;
CoglHandle layer0;
CoglHandle tex_handle;
GLfloat *v;
int i;
TextureSlicedPolygonState state;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
/* We can assume in this case that we have at least one layer in the
* material that corresponds to a sliced cogl texture */
layers = cogl_material_get_layers (ctx->source_material);
layer0 = (CoglHandle)layers->data;
tex_handle = cogl_material_layer_get_texture (layer0);
v = (GLfloat *)ctx->logged_vertices->data;
for (i = 0; i < n_vertices; i++)
{
guint8 *c;
v[0] = vertices[i].x;
v[1] = vertices[i].y;
v[2] = vertices[i].z;
if (use_color)
{
/* NB: [X,Y,Z,TX,TY,R,G,B,A,...] */
c = (guint8 *) (v + 5);
c[0] = cogl_color_get_red_byte (&vertices[i].color);
c[1] = cogl_color_get_green_byte (&vertices[i].color);
c[2] = cogl_color_get_blue_byte (&vertices[i].color);
c[3] = cogl_color_get_alpha_byte (&vertices[i].color);
}
v += stride;
}
state.stride = stride;
state.vertices = vertices;
state.n_vertices = n_vertices;
_cogl_texture_foreach_sub_texture_in_region (tex_handle,
0, 0, 1, 1,
draw_polygon_sub_texture_cb,
&state);
}
static void
_cogl_multitexture_polygon_single_primitive (const CoglTextureVertex *vertices,
guint n_vertices,
guint n_layers,
guint stride,
gboolean use_color,
guint32 fallback_layers)
{
CoglHandle material;
const GList *layers;
int i;
GList *tmp;
GLfloat *v;
CoglMaterialFlushOptions options;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
material = ctx->source_material;
layers = cogl_material_get_layers (material);
/* Convert the vertices into an array of GLfloats ready to pass to
OpenGL */
for (v = (GLfloat *)ctx->logged_vertices->data, i = 0;
i < n_vertices;
v += stride, i++)
{
guint8 *c;
int j;
/* NB: [X,Y,Z,TX,TY...,R,G,B,A,...] */
v[0] = vertices[i].x;
v[1] = vertices[i].y;
v[2] = vertices[i].z;
for (tmp = (GList *)layers, j = 0; tmp != NULL; tmp = tmp->next, j++)
{
CoglHandle layer = (CoglHandle)tmp->data;
CoglHandle tex_handle;
GLfloat *t;
float tx, ty;
tex_handle = cogl_material_layer_get_texture (layer);
/* COGL_INVALID_HANDLE textures will be handled in
* _cogl_material_flush_layers_gl_state but there is no need to worry
* about scaling texture coordinates in this case */
if (tex_handle == COGL_INVALID_HANDLE)
continue;
tx = vertices[i].tx;
ty = vertices[i].ty;
_cogl_texture_transform_coords_to_gl (tex_handle, &tx, &ty);
/* NB: [X,Y,Z,TX,TY...,R,G,B,A,...] */
t = v + 3 + 2 * j;
t[0] = tx;
t[1] = ty;
}
if (use_color)
{
/* NB: [X,Y,Z,TX,TY...,R,G,B,A,...] */
c = (guint8 *) (v + 3 + 2 * n_layers);
c[0] = cogl_color_get_red_byte (&vertices[i].color);
c[1] = cogl_color_get_green_byte (&vertices[i].color);
c[2] = cogl_color_get_blue_byte (&vertices[i].color);
c[3] = cogl_color_get_alpha_byte (&vertices[i].color);
}
}
options.flags = COGL_MATERIAL_FLUSH_FALLBACK_MASK;
if (use_color)
options.flags |= COGL_MATERIAL_FLUSH_SKIP_GL_COLOR;
options.fallback_layers = fallback_layers;
_cogl_material_flush_gl_state (ctx->source_material, &options);
GE (glDrawArrays (GL_TRIANGLE_FAN, 0, n_vertices));
}
void
cogl_polygon (const CoglTextureVertex *vertices,
guint n_vertices,
gboolean use_color)
{
CoglHandle material;
const GList *layers, *tmp;
int n_layers;
gboolean use_sliced_polygon_fallback = FALSE;
guint32 fallback_layers = 0;
int i;
gulong enable_flags;
guint stride;
gsize stride_bytes;
GLfloat *v;
int prev_n_texcoord_arrays_enabled;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
_cogl_journal_flush ();
/* NB: _cogl_framebuffer_flush_state may disrupt various state (such
* as the material state) when flushing the clip stack, so should
* always be done first when preparing to draw. */
_cogl_framebuffer_flush_state (_cogl_get_framebuffer (), 0);
material = ctx->source_material;
layers = cogl_material_get_layers (ctx->source_material);
n_layers = g_list_length ((GList *)layers);
for (tmp = layers, i = 0; tmp != NULL; tmp = tmp->next, i++)
{
CoglHandle layer = tmp->data;
CoglHandle tex_handle = cogl_material_layer_get_texture (layer);
/* COGL_INVALID_HANDLE textures will be handled in
* _cogl_material_flush_layers_gl_state */
if (tex_handle == COGL_INVALID_HANDLE)
continue;
if (i == 0 && cogl_texture_is_sliced (tex_handle))
{
#if defined (HAVE_COGL_GLES) || defined (HAVE_COGL_GLES2)
{
static gboolean warning_seen = FALSE;
if (!warning_seen)
g_warning ("cogl_polygon does not work for sliced textures "
"on GL ES");
warning_seen = TRUE;
return;
}
#endif
if (n_layers > 1)
{
static gboolean warning_seen = FALSE;
if (!warning_seen)
{
g_warning ("Disabling layers 1..n since multi-texturing with "
"cogl_polygon isn't supported when using sliced "
"textures\n");
warning_seen = TRUE;
}
}
use_sliced_polygon_fallback = TRUE;
n_layers = 1;
if (cogl_material_layer_get_min_filter (layer) != GL_NEAREST
|| cogl_material_layer_get_mag_filter (layer) != GL_NEAREST)
{
static gboolean warning_seen = FALSE;
if (!warning_seen)
{
g_warning ("cogl_texture_polygon does not work for sliced textures "
"when the minification and magnification filters are not "
"CGL_NEAREST");
warning_seen = TRUE;
}
return;
}
#ifdef HAVE_COGL_GL
{
/* Temporarily change the wrapping mode on all of the slices to use
* a transparent border
* XXX: it's doesn't look like we save/restore this, like
* the comment implies? */
_cogl_texture_set_wrap_mode_parameter (tex_handle,
GL_CLAMP_TO_BORDER);
}
#endif
break;
}
if (cogl_texture_is_sliced (tex_handle))
{
static gboolean warning_seen = FALSE;
if (!warning_seen)
g_warning ("Disabling layer %d of the current source material, "
"because texturing with the vertex buffer API is not "
"currently supported using sliced textures, or "
"textures with waste\n", i);
warning_seen = TRUE;
fallback_layers |= (1 << i);
continue;
}
}
/* Our data is arranged like:
* [X, Y, Z, TX0, TY0, TX1, TY1..., R, G, B, A,...] */
stride = 3 + (2 * n_layers) + (use_color ? 1 : 0);
stride_bytes = stride * sizeof (GLfloat);
/* Make sure there is enough space in the global vertex
array. This is used so we can render the polygon with a single
call to OpenGL but still support any number of vertices */
g_array_set_size (ctx->logged_vertices, n_vertices * stride);
v = (GLfloat *)ctx->logged_vertices->data;
/* Prepare GL state */
enable_flags = COGL_ENABLE_VERTEX_ARRAY;
enable_flags |= _cogl_material_get_cogl_enable_flags (ctx->source_material);
if (ctx->enable_backface_culling)
enable_flags |= COGL_ENABLE_BACKFACE_CULLING;
if (use_color)
{
enable_flags |= COGL_ENABLE_COLOR_ARRAY | COGL_ENABLE_BLEND;
GE( glColorPointer (4, GL_UNSIGNED_BYTE,
stride_bytes,
/* NB: [X,Y,Z,TX,TY...,R,G,B,A,...] */
v + 3 + 2 * n_layers) );
}
cogl_enable (enable_flags);
_cogl_flush_face_winding ();
GE (glVertexPointer (3, GL_FLOAT, stride_bytes, v));
for (i = 0; i < n_layers; i++)
{
GE (glClientActiveTexture (GL_TEXTURE0 + i));
GE (glEnableClientState (GL_TEXTURE_COORD_ARRAY));
GE (glTexCoordPointer (2, GL_FLOAT,
stride_bytes,
/* NB: [X,Y,Z,TX,TY...,R,G,B,A,...] */
v + 3 + 2 * i));
}
prev_n_texcoord_arrays_enabled = ctx->n_texcoord_arrays_enabled;
ctx->n_texcoord_arrays_enabled = n_layers;
for (; i < prev_n_texcoord_arrays_enabled; i++)
{
GE (glClientActiveTexture (GL_TEXTURE0 + i));
GE (glDisableClientState (GL_TEXTURE_COORD_ARRAY));
}
if (use_sliced_polygon_fallback)
_cogl_texture_polygon_multiple_primitives (vertices,
n_vertices,
stride,
use_color);
else
_cogl_multitexture_polygon_single_primitive (vertices,
n_vertices,
n_layers,
stride,
use_color,
fallback_layers);
/* Reset the size of the logged vertex array because rendering
rectangles expects it to start at 0 */
g_array_set_size (ctx->logged_vertices, 0);
}
static void
_cogl_path_add_node (gboolean new_sub_path,
float x,
float y)
{
CoglPathNode new_node;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
new_node.x = x;
new_node.y = y;
new_node.path_size = 0;
if (new_sub_path || ctx->path_nodes->len == 0)
ctx->last_path = ctx->path_nodes->len;
g_array_append_val (ctx->path_nodes, new_node);
g_array_index (ctx->path_nodes, CoglPathNode, ctx->last_path).path_size++;
if (ctx->path_nodes->len == 1)
{
ctx->path_nodes_min.x = ctx->path_nodes_max.x = x;
ctx->path_nodes_min.y = ctx->path_nodes_max.y = y;
}
else
{
if (x < ctx->path_nodes_min.x) ctx->path_nodes_min.x = x;
if (x > ctx->path_nodes_max.x) ctx->path_nodes_max.x = x;
if (y < ctx->path_nodes_min.y) ctx->path_nodes_min.y = y;
if (y > ctx->path_nodes_max.y) ctx->path_nodes_max.y = y;
}
}
static void
_cogl_path_stroke_nodes (void)
{
unsigned int path_start = 0;
unsigned long enable_flags = COGL_ENABLE_VERTEX_ARRAY;
CoglMaterialFlushOptions options;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
_cogl_journal_flush ();
/* NB: _cogl_framebuffer_flush_state may disrupt various state (such
* as the material state) when flushing the clip stack, so should
* always be done first when preparing to draw. */
_cogl_framebuffer_flush_state (_cogl_get_framebuffer (), 0);
enable_flags |= _cogl_material_get_cogl_enable_flags (ctx->source_material);
cogl_enable (enable_flags);
options.flags = COGL_MATERIAL_FLUSH_DISABLE_MASK;
/* disable all texture layers */
options.disable_layers = (guint32)~0;
_cogl_material_flush_gl_state (ctx->source_material, &options);
while (path_start < ctx->path_nodes->len)
{
CoglPathNode *path = &g_array_index (ctx->path_nodes, CoglPathNode,
path_start);
GE( glVertexPointer (2, GL_FLOAT, sizeof (CoglPathNode),
(guchar *) path
+ G_STRUCT_OFFSET (CoglPathNode, x)) );
GE( glDrawArrays (GL_LINE_STRIP, 0, path->path_size) );
path_start += path->path_size;
}
}
static void
_cogl_path_get_bounds (floatVec2 nodes_min,
floatVec2 nodes_max,
float *bounds_x,
float *bounds_y,
float *bounds_w,
float *bounds_h)
{
*bounds_x = nodes_min.x;
*bounds_y = nodes_min.y;
*bounds_w = nodes_max.x - *bounds_x;
*bounds_h = nodes_max.y - *bounds_y;
}
void
_cogl_add_path_to_stencil_buffer (floatVec2 nodes_min,
floatVec2 nodes_max,
unsigned int path_size,
CoglPathNode *path,
gboolean merge,
gboolean need_clear)
{
unsigned int path_start = 0;
unsigned int sub_path_num = 0;
float bounds_x;
float bounds_y;
float bounds_w;
float bounds_h;
unsigned long enable_flags = COGL_ENABLE_VERTEX_ARRAY;
CoglHandle prev_source;
int i;
CoglHandle framebuffer = _cogl_get_framebuffer ();
CoglMatrixStack *modelview_stack =
_cogl_framebuffer_get_modelview_stack (framebuffer);
CoglMatrixStack *projection_stack =
_cogl_framebuffer_get_projection_stack (framebuffer);
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
/* We don't track changes to the stencil buffer in the journal
* so we need to flush any batched geometry first */
_cogl_journal_flush ();
/* NB: _cogl_framebuffer_flush_state may disrupt various state (such
* as the material state) when flushing the clip stack, so should
* always be done first when preparing to draw. */
_cogl_framebuffer_flush_state (framebuffer, 0);
/* Just setup a simple material that doesn't use texturing... */
prev_source = cogl_handle_ref (ctx->source_material);
cogl_set_source (ctx->stencil_material);
_cogl_material_flush_gl_state (ctx->source_material, NULL);
enable_flags |=
_cogl_material_get_cogl_enable_flags (ctx->source_material);
cogl_enable (enable_flags);
_cogl_path_get_bounds (nodes_min, nodes_max,
&bounds_x, &bounds_y, &bounds_w, &bounds_h);
GE( glEnable (GL_STENCIL_TEST) );
GE( glColorMask (FALSE, FALSE, FALSE, FALSE) );
GE( glDepthMask (FALSE) );
if (merge)
{
GE (glStencilMask (2));
GE (glStencilFunc (GL_LEQUAL, 0x2, 0x6));
}
else
{
/* If we're not using the stencil buffer for clipping then we
don't need to clear the whole stencil buffer, just the area
that will be drawn */
if (need_clear)
cogl_clear (NULL, COGL_BUFFER_BIT_STENCIL);
else
{
/* Just clear the bounding box */
GE( glStencilMask (~(GLuint) 0) );
GE( glStencilOp (GL_ZERO, GL_ZERO, GL_ZERO) );
cogl_rectangle (bounds_x, bounds_y,
bounds_x + bounds_w, bounds_y + bounds_h);
/* Make sure the rectangle hits the stencil buffer before
* directly changing other GL state. */
_cogl_journal_flush ();
/* NB: The journal flushing may trash the modelview state and
* enable flags */
_cogl_matrix_stack_flush_to_gl (modelview_stack,
COGL_MATRIX_MODELVIEW);
cogl_enable (enable_flags);
}
GE (glStencilMask (1));
GE (glStencilFunc (GL_LEQUAL, 0x1, 0x3));
}
GE (glStencilOp (GL_INVERT, GL_INVERT, GL_INVERT));
for (i = 0; i < ctx->n_texcoord_arrays_enabled; i++)
{
GE (glClientActiveTexture (GL_TEXTURE0 + i));
GE (glDisableClientState (GL_TEXTURE_COORD_ARRAY));
}
ctx->n_texcoord_arrays_enabled = 0;
while (path_start < path_size)
{
GE (glVertexPointer (2, GL_FLOAT, sizeof (CoglPathNode),
(guchar *) path
+ G_STRUCT_OFFSET (CoglPathNode, x)));
GE (glDrawArrays (GL_TRIANGLE_FAN, 0, path->path_size));
if (sub_path_num > 0)
{
/* Union the two stencil buffers bits into the least
significant bit */
GE (glStencilMask (merge ? 6 : 3));
GE (glStencilOp (GL_ZERO, GL_REPLACE, GL_REPLACE));
cogl_rectangle (bounds_x, bounds_y,
bounds_x + bounds_w, bounds_y + bounds_h);
/* Make sure the rectangle hits the stencil buffer before
* directly changing other GL state. */
_cogl_journal_flush ();
/* NB: The journal flushing may trash the modelview state and
* enable flags */
_cogl_matrix_stack_flush_to_gl (modelview_stack,
COGL_MATRIX_MODELVIEW);
cogl_enable (enable_flags);
GE (glStencilOp (GL_INVERT, GL_INVERT, GL_INVERT));
}
GE (glStencilMask (merge ? 4 : 2));
path_start += path->path_size;
path += path->path_size;
sub_path_num++;
}
if (merge)
{
/* Now we have the new stencil buffer in bit 1 and the old
stencil buffer in bit 0 so we need to intersect them */
GE (glStencilMask (3));
GE (glStencilFunc (GL_NEVER, 0x2, 0x3));
GE (glStencilOp (GL_DECR, GL_DECR, GL_DECR));
/* Decrement all of the bits twice so that only pixels where the
value is 3 will remain */
_cogl_matrix_stack_push (projection_stack);
_cogl_matrix_stack_load_identity (projection_stack);
_cogl_matrix_stack_flush_to_gl (projection_stack,
COGL_MATRIX_PROJECTION);
_cogl_matrix_stack_push (modelview_stack);
_cogl_matrix_stack_load_identity (modelview_stack);
_cogl_matrix_stack_flush_to_gl (modelview_stack,
COGL_MATRIX_MODELVIEW);
cogl_rectangle (-1.0, -1.0, 1.0, 1.0);
cogl_rectangle (-1.0, -1.0, 1.0, 1.0);
/* Make sure these rectangles hit the stencil buffer before we
* restore the stencil op/func. */
_cogl_journal_flush ();
_cogl_matrix_stack_pop (modelview_stack);
_cogl_matrix_stack_pop (projection_stack);
}
GE (glStencilMask (~(GLuint) 0));
GE (glDepthMask (TRUE));
GE (glColorMask (TRUE, TRUE, TRUE, TRUE));
GE (glStencilFunc (GL_EQUAL, 0x1, 0x1));
GE (glStencilOp (GL_KEEP, GL_KEEP, GL_KEEP));
/* restore the original material */
cogl_set_source (prev_source);
cogl_handle_unref (prev_source);
}
static gint
compare_ints (gconstpointer a,
gconstpointer b)
{
return GPOINTER_TO_INT(a)-GPOINTER_TO_INT(b);
}
static void
_cogl_path_fill_nodes_scanlines (CoglPathNode *path,
unsigned int path_size,
int bounds_x,
int bounds_y,
unsigned int bounds_w,
unsigned int bounds_h)
{
/* This is our edge list it stores intersections between our
* curve and scanlines, it should probably be implemented with a
* data structure that has smaller overhead for inserting the
* curve/scanline intersections.
*/
GSList **scanlines = g_alloca (bounds_h * sizeof (GSList *));
int i;
int prev_x;
int prev_y;
int first_x;
int first_y;
int lastdir = -2; /* last direction we vere moving */
int lastline = -1; /* the previous scanline we added to */
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
/* We are going to use GL to draw directly so make sure any
* previously batched geometry gets to GL before we start...
*/
_cogl_journal_flush ();
/* NB: _cogl_framebuffer_flush_state may disrupt various state (such
* as the material state) when flushing the clip stack, so should
* always be done first when preparing to draw. */
_cogl_framebuffer_flush_state (_cogl_get_framebuffer (), 0);
_cogl_material_flush_gl_state (ctx->source_material, NULL);
cogl_enable (COGL_ENABLE_VERTEX_ARRAY
| (ctx->color_alpha < 255 ? COGL_ENABLE_BLEND : 0));
/* clear scanline intersection lists */
for (i = 0; i < bounds_h; i++)
scanlines[i]=NULL;
first_x = prev_x = path->x;
first_y = prev_y = path->y;
/* create scanline intersection list */
for (i=1; i < path_size; i++)
{
int dest_x = path[i].x;
int dest_y = path[i].y;
int ydir;
int dx;
int dy;
int y;
fill_close:
dx = dest_x - prev_x;
dy = dest_y - prev_y;
if (dy < 0)
ydir = -1;
else if (dy > 0)
ydir = 1;
else
ydir = 0;
/* do linear interpolation between vertices */
for (y = prev_y; y != dest_y; y += ydir)
{
/* only add a point if the scanline has changed and we're
* within bounds.
*/
if (y - bounds_y >= 0 &&
y - bounds_y < bounds_h &&
lastline != y)
{
gint x = prev_x + (dx * (y-prev_y)) / dy;
scanlines[ y - bounds_y ]=
g_slist_insert_sorted (scanlines[ y - bounds_y],
GINT_TO_POINTER(x),
compare_ints);
if (ydir != lastdir && /* add a double entry when changing */
lastdir != -2) /* vertical direction */
scanlines[ y - bounds_y ]=
g_slist_insert_sorted (scanlines[ y - bounds_y],
GINT_TO_POINTER(x),
compare_ints);
lastdir = ydir;
lastline = y;
}
}
prev_x = dest_x;
prev_y = dest_y;
/* if we're on the last knot, fake the first vertex being a
next one */
if (path_size == i+1)
{
dest_x = first_x;
dest_y = first_y;
i++; /* to make the loop finally end */
goto fill_close;
}
}
{
int spans = 0;
int span_no;
GLfloat *coords;
/* count number of spans */
for (i = 0; i < bounds_h; i++)
{
GSList *iter = scanlines[i];
while (iter)
{
GSList *next = iter->next;
if (!next)
{
break;
}
/* draw the segments that should be visible */
spans ++;
iter = next->next;
}
}
coords = g_malloc0 (spans * sizeof (GLfloat) * 3 * 2 * 2);
span_no = 0;
/* build list of triangles */
for (i = 0; i < bounds_h; i++)
{
GSList *iter = scanlines[i];
while (iter)
{
GSList *next = iter->next;
GLfloat x_0, x_1;
GLfloat y_0, y_1;
if (!next)
break;
x_0 = GPOINTER_TO_INT (iter->data);
x_1 = GPOINTER_TO_INT (next->data);
y_0 = bounds_y + i;
y_1 = bounds_y + i + 1.0625f;
/* render scanlines 1.0625 high to avoid gaps when
transformed */
coords[span_no * 12 + 0] = x_0;
coords[span_no * 12 + 1] = y_0;
coords[span_no * 12 + 2] = x_1;
coords[span_no * 12 + 3] = y_0;
coords[span_no * 12 + 4] = x_1;
coords[span_no * 12 + 5] = y_1;
coords[span_no * 12 + 6] = x_0;
coords[span_no * 12 + 7] = y_0;
coords[span_no * 12 + 8] = x_0;
coords[span_no * 12 + 9] = y_1;
coords[span_no * 12 + 10] = x_1;
coords[span_no * 12 + 11] = y_1;
span_no ++;
iter = next->next;
}
}
for (i = 0; i < bounds_h; i++)
g_slist_free (scanlines[i]);
/* render triangles */
GE (glVertexPointer (2, GL_FLOAT, 0, coords ));
GE (glDrawArrays (GL_TRIANGLES, 0, spans * 2 * 3));
g_free (coords);
}
}
static void
_cogl_path_fill_nodes (void)
{
float bounds_x;
float bounds_y;
float bounds_w;
float bounds_h;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
_cogl_path_get_bounds (ctx->path_nodes_min, ctx->path_nodes_max,
&bounds_x, &bounds_y, &bounds_w, &bounds_h);
if (G_LIKELY (!(cogl_debug_flags & COGL_DEBUG_FORCE_SCANLINE_PATHS)) &&
cogl_features_available (COGL_FEATURE_STENCIL_BUFFER))
{
CoglHandle framebuffer;
CoglClipStackState *clip_state;
_cogl_journal_flush ();
framebuffer = _cogl_get_framebuffer ();
clip_state = _cogl_framebuffer_get_clip_state (framebuffer);
_cogl_add_path_to_stencil_buffer (ctx->path_nodes_min,
ctx->path_nodes_max,
ctx->path_nodes->len,
&g_array_index (ctx->path_nodes,
CoglPathNode, 0),
clip_state->stencil_used,
FALSE);
cogl_rectangle (bounds_x, bounds_y,
bounds_x + bounds_w, bounds_y + bounds_h);
/* The stencil buffer now contains garbage so the clip area needs to
be rebuilt */
_cogl_clip_stack_state_dirty (clip_state);
}
else
{
unsigned int path_start = 0;
while (path_start < ctx->path_nodes->len)
{
CoglPathNode *path = &g_array_index (ctx->path_nodes, CoglPathNode,
path_start);
_cogl_path_fill_nodes_scanlines (path,
path->path_size,
bounds_x, bounds_y,
bounds_w, bounds_h);
path_start += path->path_size;
}
}
}
void
cogl_path_fill (void)
{
cogl_path_fill_preserve ();
cogl_path_new ();
}
void
cogl_path_fill_preserve (void)
{
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
if (ctx->path_nodes->len == 0)
return;
_cogl_path_fill_nodes ();
}
void
cogl_path_stroke (void)
{
cogl_path_stroke_preserve ();
cogl_path_new ();
}
void
cogl_path_stroke_preserve (void)
{
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
if (ctx->path_nodes->len == 0)
return;
_cogl_path_stroke_nodes ();
}
void
cogl_path_move_to (float x,
float y)
{
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
/* FIXME: handle multiple contours maybe? */
_cogl_path_add_node (TRUE, x, y);
ctx->path_start.x = x;
ctx->path_start.y = y;
ctx->path_pen = ctx->path_start;
}
void
cogl_path_rel_move_to (float x,
float y)
{
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
cogl_path_move_to (ctx->path_pen.x + x,
ctx->path_pen.y + y);
}
void
cogl_path_line_to (float x,
float y)
{
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
_cogl_path_add_node (FALSE, x, y);
ctx->path_pen.x = x;
ctx->path_pen.y = y;
}
void
cogl_path_rel_line_to (float x,
float y)
{
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
cogl_path_line_to (ctx->path_pen.x + x,
ctx->path_pen.y + y);
}
void
cogl_path_close (void)
{
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
_cogl_path_add_node (FALSE, ctx->path_start.x, ctx->path_start.y);
ctx->path_pen = ctx->path_start;
}
void
cogl_path_new (void)
{
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
g_array_set_size (ctx->path_nodes, 0);
}
void
cogl_path_line (float x_1,
float y_1,
float x_2,
float y_2)
{
cogl_path_move_to (x_1, y_1);
cogl_path_line_to (x_2, y_2);
}
void
cogl_path_polyline (float *coords,
gint num_points)
{
gint c = 0;
cogl_path_move_to (coords[0], coords[1]);
for (c = 1; c < num_points; ++c)
cogl_path_line_to (coords[2*c], coords[2*c+1]);
}
void
cogl_path_polygon (float *coords,
gint num_points)
{
cogl_path_polyline (coords, num_points);
cogl_path_close ();
}
void
cogl_path_rectangle (float x_1,
float y_1,
float x_2,
float y_2)
{
cogl_path_move_to (x_1, y_1);
cogl_path_line_to (x_2, y_1);
cogl_path_line_to (x_2, y_2);
cogl_path_line_to (x_1, y_2);
cogl_path_close ();
}
static void
_cogl_path_arc (float center_x,
float center_y,
float radius_x,
float radius_y,
float angle_1,
float angle_2,
float angle_step,
guint move_first)
{
float a = 0x0;
float cosa = 0x0;
float sina = 0x0;
float px = 0x0;
float py = 0x0;
/* Fix invalid angles */
if (angle_1 == angle_2 || angle_step == 0x0)
return;
if (angle_step < 0x0)
angle_step = -angle_step;
/* Walk the arc by given step */
a = angle_1;
while (a != angle_2)
{
cosa = cosf (a * (G_PI/180.0));
sina = sinf (a * (G_PI/180.0));
px = center_x + (cosa * radius_x);
py = center_y + (sina * radius_y);
if (a == angle_1 && move_first)
cogl_path_move_to (px, py);
else
cogl_path_line_to (px, py);
if (G_LIKELY (angle_2 > angle_1))
{
a += angle_step;
if (a > angle_2)
a = angle_2;
}
else
{
a -= angle_step;
if (a < angle_2)
a = angle_2;
}
}
/* Make sure the final point is drawn */
cosa = cosf (angle_2 * (G_PI/180.0));
sina = sinf (angle_2 * (G_PI/180.0));
px = center_x + (cosa * radius_x);
py = center_y + (sina * radius_y);
cogl_path_line_to (px, py);
}
void
cogl_path_arc (float center_x,
float center_y,
float radius_x,
float radius_y,
float angle_1,
float angle_2)
{
float angle_step = 10;
/* it is documented that a move to is needed to create a freestanding
* arc
*/
_cogl_path_arc (center_x, center_y,
radius_x, radius_y,
angle_1, angle_2,
angle_step, 0 /* no move */);
}
void
cogl_path_arc_rel (float center_x,
float center_y,
float radius_x,
float radius_y,
float angle_1,
float angle_2,
float angle_step)
{
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
_cogl_path_arc (ctx->path_pen.x + center_x,
ctx->path_pen.y + center_y,
radius_x, radius_y,
angle_1, angle_2,
angle_step, 0 /* no move */);
}
void
cogl_path_ellipse (float center_x,
float center_y,
float radius_x,
float radius_y)
{
float angle_step = 10;
/* FIXME: if shows to be slow might be optimized
* by mirroring just a quarter of it */
_cogl_path_arc (center_x, center_y,
radius_x, radius_y,
0, 360,
angle_step, 1 /* move first */);
cogl_path_close();
}
void
cogl_path_round_rectangle (float x_1,
float y_1,
float x_2,
float y_2,
float radius,
float arc_step)
{
float inner_width = x_2 - x_1 - radius * 2;
float inner_height = y_2 - y_1 - radius * 2;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
cogl_path_move_to (x_1, y_1 + radius);
cogl_path_arc_rel (radius, 0,
radius, radius,
180,
270,
arc_step);
cogl_path_line_to (ctx->path_pen.x + inner_width,
ctx->path_pen.y);
cogl_path_arc_rel (0, radius,
radius, radius,
-90,
0,
arc_step);
cogl_path_line_to (ctx->path_pen.x,
ctx->path_pen.y + inner_height);
cogl_path_arc_rel (-radius, 0,
radius, radius,
0,
90,
arc_step);
cogl_path_line_to (ctx->path_pen.x - inner_width,
ctx->path_pen.y);
cogl_path_arc_rel (0, -radius,
radius, radius,
90,
180,
arc_step);
cogl_path_close ();
}
static void
_cogl_path_bezier3_sub (CoglBezCubic *cubic)
{
CoglBezCubic cubics[_COGL_MAX_BEZ_RECURSE_DEPTH];
CoglBezCubic *cleft;
CoglBezCubic *cright;
CoglBezCubic *c;
floatVec2 dif1;
floatVec2 dif2;
floatVec2 mm;
floatVec2 c1;
floatVec2 c2;
floatVec2 c3;
floatVec2 c4;
floatVec2 c5;
gint cindex;
/* Put first curve on stack */
cubics[0] = *cubic;
cindex = 0;
while (cindex >= 0)
{
c = &cubics[cindex];
/* Calculate distance of control points from their
* counterparts on the line between end points */
dif1.x = (c->p2.x * 3) - (c->p1.x * 2) - c->p4.x;
dif1.y = (c->p2.y * 3) - (c->p1.y * 2) - c->p4.y;
dif2.x = (c->p3.x * 3) - (c->p4.x * 2) - c->p1.x;
dif2.y = (c->p3.y * 3) - (c->p4.y * 2) - c->p1.y;
if (dif1.x < 0)
dif1.x = -dif1.x;
if (dif1.y < 0)
dif1.y = -dif1.y;
if (dif2.x < 0)
dif2.x = -dif2.x;
if (dif2.y < 0)
dif2.y = -dif2.y;
/* Pick the greatest of two distances */
if (dif1.x < dif2.x) dif1.x = dif2.x;
if (dif1.y < dif2.y) dif1.y = dif2.y;
/* Cancel if the curve is flat enough */
if (dif1.x + dif1.y <= 1.0 ||
cindex == _COGL_MAX_BEZ_RECURSE_DEPTH-1)
{
/* Add subdivision point (skip last) */
if (cindex == 0)
return;
_cogl_path_add_node (FALSE, c->p4.x, c->p4.y);
--cindex;
continue;
}
/* Left recursion goes on top of stack! */
cright = c; cleft = &cubics[++cindex];
/* Subdivide into 2 sub-curves */
c1.x = ((c->p1.x + c->p2.x) / 2);
c1.y = ((c->p1.y + c->p2.y) / 2);
mm.x = ((c->p2.x + c->p3.x) / 2);
mm.y = ((c->p2.y + c->p3.y) / 2);
c5.x = ((c->p3.x + c->p4.x) / 2);
c5.y = ((c->p3.y + c->p4.y) / 2);
c2.x = ((c1.x + mm.x) / 2);
c2.y = ((c1.y + mm.y) / 2);
c4.x = ((mm.x + c5.x) / 2);
c4.y = ((mm.y + c5.y) / 2);
c3.x = ((c2.x + c4.x) / 2);
c3.y = ((c2.y + c4.y) / 2);
/* Add left recursion to stack */
cleft->p1 = c->p1;
cleft->p2 = c1;
cleft->p3 = c2;
cleft->p4 = c3;
/* Add right recursion to stack */
cright->p1 = c3;
cright->p2 = c4;
cright->p3 = c5;
cright->p4 = c->p4;
}
}
void
cogl_path_curve_to (float x_1,
float y_1,
float x_2,
float y_2,
float x_3,
float y_3)
{
CoglBezCubic cubic;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
/* Prepare cubic curve */
cubic.p1 = ctx->path_pen;
cubic.p2.x = x_1;
cubic.p2.y = y_1;
cubic.p3.x = x_2;
cubic.p3.y = y_2;
cubic.p4.x = x_3;
cubic.p4.y = y_3;
/* Run subdivision */
_cogl_path_bezier3_sub (&cubic);
/* Add last point */
_cogl_path_add_node (FALSE, cubic.p4.x, cubic.p4.y);
ctx->path_pen = cubic.p4;
}
void
cogl_path_rel_curve_to (float x_1,
float y_1,
float x_2,
float y_2,
float x_3,
float y_3)
{
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
cogl_path_curve_to (ctx->path_pen.x + x_1,
ctx->path_pen.y + y_1,
ctx->path_pen.x + x_2,
ctx->path_pen.y + y_2,
ctx->path_pen.x + x_3,
ctx->path_pen.y + y_3);
}
/* If second order beziers were needed the following code could
* be re-enabled:
*/
#if 0
static void
_cogl_path_bezier2_sub (CoglBezQuad *quad)
{
CoglBezQuad quads[_COGL_MAX_BEZ_RECURSE_DEPTH];
CoglBezQuad *qleft;
CoglBezQuad *qright;
CoglBezQuad *q;
floatVec2 mid;
floatVec2 dif;
floatVec2 c1;
floatVec2 c2;
floatVec2 c3;
gint qindex;
/* Put first curve on stack */
quads[0] = *quad;
qindex = 0;
/* While stack is not empty */
while (qindex >= 0)
{
q = &quads[qindex];
/* Calculate distance of control point from its
* counterpart on the line between end points */
mid.x = ((q->p1.x + q->p3.x) / 2);
mid.y = ((q->p1.y + q->p3.y) / 2);
dif.x = (q->p2.x - mid.x);
dif.y = (q->p2.y - mid.y);
if (dif.x < 0) dif.x = -dif.x;
if (dif.y < 0) dif.y = -dif.y;
/* Cancel if the curve is flat enough */
if (dif.x + dif.y <= 1.0 ||
qindex == _COGL_MAX_BEZ_RECURSE_DEPTH - 1)
{
/* Add subdivision point (skip last) */
if (qindex == 0) return;
_cogl_path_add_node (FALSE, q->p3.x, q->p3.y);
--qindex; continue;
}
/* Left recursion goes on top of stack! */
qright = q; qleft = &quads[++qindex];
/* Subdivide into 2 sub-curves */
c1.x = ((q->p1.x + q->p2.x) / 2);
c1.y = ((q->p1.y + q->p2.y) / 2);
c3.x = ((q->p2.x + q->p3.x) / 2);
c3.y = ((q->p2.y + q->p3.y) / 2);
c2.x = ((c1.x + c3.x) / 2);
c2.y = ((c1.y + c3.y) / 2);
/* Add left recursion onto stack */
qleft->p1 = q->p1;
qleft->p2 = c1;
qleft->p3 = c2;
/* Add right recursion onto stack */
qright->p1 = c2;
qright->p2 = c3;
qright->p3 = q->p3;
}
}
void
cogl_path_curve2_to (float x_1,
float y_1,
float x_2,
float y_2)
{
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
CoglBezQuad quad;
/* Prepare quadratic curve */
quad.p1 = ctx->path_pen;
quad.p2.x = x_1;
quad.p2.y = y_1;
quad.p3.x = x_2;
quad.p3.y = y_2;
/* Run subdivision */
_cogl_path_bezier2_sub (&quad);
/* Add last point */
_cogl_path_add_node (FALSE, quad.p3.x, quad.p3.y);
ctx->path_pen = quad.p3;
}
void
cogl_rel_curve2_to (float x_1,
float y_1,
float x_2,
float y_2)
{
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
cogl_path_curve2_to (ctx->path_pen.x + x_1,
ctx->path_pen.y + y_1,
ctx->path_pen.x + x_2,
ctx->path_pen.y + y_2);
}
#endif
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