mutter/cogl/cogl-primitives.c
Robert Bragg 181bf92086 [cogl] Use clockwise face winding for offscreen buffers with culling enabled
Because Cogl defines the origin for texture as top left and offscreen draw
buffers can be used to render to textures, we (internally) force all
offscreen rendering to be upside down. (because OpenGL defines the origin
to be bottom left)

By forcing the users scene to be rendered upside down though we also reverse
the winding order of all the drawn triangles which may interfere with the
users use of backface culling.  This patch ensures that we reverse the
winding order for a front face (if culling is in use) while rendering
offscreen so we don't conflict with the users back face culling.
2009-11-04 03:34:03 +00:00

1591 lines
47 KiB
C

/*
* 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-draw-buffer-private.h"
#include <string.h>
#include <math.h>
#define _COGL_MAX_BEZ_RECURSE_DEPTH 16
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
{
CoglTextureVertex *vertices;
int n_vertices;
int stride;
} TextureSlicedPolygonState;
/* these are defined in the particular backend */
void _cogl_path_add_node (gboolean new_sub_path,
float x,
float y);
void _cogl_path_fill_nodes ();
void _cogl_path_stroke_nodes ();
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 (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 (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 (CoglTextureVertex *vertices,
guint n_vertices,
gboolean use_color)
{
CoglHandle material;
const GList *layers;
int n_layers;
GList *tmp;
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_draw_buffer_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_draw_buffer_flush_state (_cogl_get_draw_buffer (), 0);
material = ctx->source_material;
layers = cogl_material_get_layers (ctx->source_material);
n_layers = g_list_length ((GList *)layers);
for (tmp = (GList *)layers, i = 0; tmp != NULL; tmp = tmp->next, i++)
{
CoglHandle layer = (CoglHandle)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);
}
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