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gl-renderer: Do not expose clipper_clip() in header 

There is no need to expose it since it can be accessed by passing
non-axis aligned quads. Move existing tests to the quad clipper.

Signed-off-by: Loïc Molinari <loic.molinari@collabora.com>
This commit is contained in:
Loïc Molinari 2024-04-15 15:57:15 +02:00 committed by Marius Vlad
parent bef1f5fd7d
commit ce1705435f
3 changed files with 97 additions and 108 deletions
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16
libweston/vertex-clipping.c
View File

@ -291,11 +291,19 @@ clip_polygon_bottom(struct clip_context *ctx, const struct polygon8 *src,
return ctx->vertices - dst;
}
/* General purpose polygon clipping algorithm based on Sutherland-Hodgman:
/* General purpose clipping function. Compute the boundary vertices of the
* intersection of a 'polygon' and a clipping 'box'. 'polygon' points to an
* array of 4 vertices defining a convex polygon of any winding order. 'box'
* points to an array of 2 vertices where the values of the 1st vertex are less
* than or equal to the values of the 2nd vertex. Up to 8 resulting vertices,
* using 'polygon' winding order, are written to 'vertices'. The return value is
* the number of vertices created.
*
* Based on Sutherland-Hodgman algorithm:
* https://www.codeguru.com/cplusplus/polygon-clipping/
*/
WESTON_EXPORT_FOR_TESTS int
clipper_clip(const struct clipper_vertex polygon[4],
static int
clip(const struct clipper_vertex polygon[4],
const struct clipper_vertex box[2],
struct clipper_vertex *restrict vertices)
{
@ -386,7 +394,7 @@ clipper_quad_clip(struct clipper_quad *quad,
/* Then use our general purpose clipping algorithm:
*/
n = clipper_clip(quad->polygon, box, vertices);
n = clip(quad->polygon, box, vertices);
if (n < 3)
return 0;

14
libweston/vertex-clipping.h
View File

@ -39,20 +39,6 @@ struct clipper_quad {
bool axis_aligned;
};
/*
* General purpose clipping function. Compute the boundary vertices of the
* intersection of a 'polygon' and a clipping 'box'. 'polygon' points to an
* array of 4 vertices defining a convex polygon of any winding order. 'box'
* points to an array of 2 vertices where the values of the 1st vertex are less
* than or equal to the values of the 2nd vertex. Up to 8 resulting vertices,
* using 'polygon' winding order, are written to 'vertices'. The return value is
* the number of vertices created.
*/
int
clipper_clip(const struct clipper_vertex polygon[4],
const struct clipper_vertex box[2],
struct clipper_vertex *restrict vertices);
/*
* Initialize a 'quad' clipping context. 'polygon' points to an array of 4
* vertices defining a convex quadrilateral of any winding order. Call

171
tests/vertex-clip-test.c
View File

@ -77,94 +77,6 @@ assert_vertices(const struct clipper_vertex *clipped, int clipped_n,
}
}
/* clipper_clip() tests: */
static const struct vertex_clip_test_data clip_expected_data[] = {
/* Quad inside box. */
{
.box = BOX (50.0f, 50.0f, 100.0f, 100.0f),
.polygon = QUAD(51.0f, 51.0f, 99.0f, 99.0f),
.clipped = QUAD(51.0f, 51.0f, 99.0f, 99.0f),
.clipped_n = 4,
},
/* Quad bottom edge outside of box. */
{
.box = BOX (50.0f, 50.0f, 100.0f, 100.0f),
.polygon = QUAD(51.0f, 51.0f, 99.0f, 101.0f),
.clipped = QUAD(51.0f, 51.0f, 99.0f, 100.0f),
.clipped_n = 4,
},
/* Quad top edge outside of box. */
{
.box = BOX (50.0f, 50.0f, 100.0f, 100.0f),
.polygon = QUAD(51.0f, 49.0f, 99.0f, 99.0f),
.clipped = QUAD(51.0f, 50.0f, 99.0f, 99.0f),
.clipped_n = 4,
},
/* Quad left edge outside of box. */
{
.box = BOX (50.0f, 50.0f, 100.0f, 100.0f),
.polygon = QUAD(49.0f, 51.0f, 99.0f, 99.0f),
.clipped = QUAD(50.0f, 51.0f, 99.0f, 99.0f),
.clipped_n = 4,
},
/* Quad right edge outside of box. */
{
.box = BOX (50.0f, 50.0f, 100.0f, 100.0f),
.polygon = QUAD(51.0f, 51.0f, 101.0f, 99.0f),
.clipped = QUAD(51.0f, 51.0f, 100.0f, 99.0f),
.clipped_n = 4,
},
/* Rotated quad with edges adjacent to box corners. */
{
.box = BOX(50.0f, 50.0f, 100.0f, 100.0f),
.polygon = {{ 25.0f, 75.0f}, {75.0f, 25.0f},
{125.0f, 75.0f}, {75.0f, 125.0f}},
.clipped = QUAD(50.0f, 50.0f, 100.0f, 100.0f),
.clipped_n = 4,
},
/* Rotated quad with edges cutting out box corners. */
{
.box = BOX(50.0f, 50.0f, 100.0f, 100.0f),
.polygon = {{ 37.5f, 75.0f}, { 75.0f, 37.5f},
{112.5f, 75.0f}, { 75.0f, 112.5f}},
.clipped = {{ 62.5f, 50.0f}, { 87.5f, 50.0f},
{100.0f, 62.5f}, {100.0f, 87.5f},
{ 87.5f, 100.0f}, { 62.5f, 100.0f},
{ 50.0f, 87.5f}, { 50.0f, 62.5f}},
.clipped_n = 8,
},
/* Same as above using counter-clockwise winding. */
{
.box = BOX(50.0f, 50.0f, 100.0f, 100.0f),
.polygon = {{ 37.5f, 75.0f}, { 75.0f, 112.5f},
{112.5f, 75.0f}, { 75.0f, 37.5f}},
.clipped = {{ 62.5f, 50.0f}, { 50.0f, 62.5f},
{ 50.0f, 87.5f}, { 62.5f, 100.0f},
{ 87.5f, 100.0f}, {100.0f, 87.5f},
{100.0f, 62.5f}, { 87.5f, 50.0f}},
.clipped_n = 8,
},
};
TEST_P(clip_expected, clip_expected_data)
{
struct vertex_clip_test_data *tdata = data;
struct clipper_vertex clipped[8];
int clipped_n;
clipped_n = clipper_clip(tdata->polygon, tdata->box, clipped);
assert_vertices(clipped, clipped_n, tdata->clipped, tdata->clipped_n);
}
/* clipper_quad_clip() tests: */
static const struct vertex_clip_test_data quad_clip_expected_data[] = {
@ -661,6 +573,89 @@ static const struct vertex_clip_test_data quad_clip_expected_data[] = {
.clipped_n = 4,
},
/* General purpose clipper tests: */
/* Quad inside box. */
{
.aligned = false,
.box = BOX (50.0f, 50.0f, 100.0f, 100.0f),
.polygon = QUAD(51.0f, 51.0f, 99.0f, 99.0f),
.clipped = QUAD(51.0f, 51.0f, 99.0f, 99.0f),
.clipped_n = 4,
},
/* Quad bottom edge outside of box. */
{
.aligned = false,
.box = BOX (50.0f, 50.0f, 100.0f, 100.0f),
.polygon = QUAD(51.0f, 51.0f, 99.0f, 101.0f),
.clipped = QUAD(51.0f, 51.0f, 99.0f, 100.0f),
.clipped_n = 4,
},
/* Quad top edge outside of box. */
{
.aligned = false,
.box = BOX (50.0f, 50.0f, 100.0f, 100.0f),
.polygon = QUAD(51.0f, 49.0f, 99.0f, 99.0f),
.clipped = QUAD(51.0f, 50.0f, 99.0f, 99.0f),
.clipped_n = 4,
},
/* Quad left edge outside of box. */
{
.aligned = false,
.box = BOX (50.0f, 50.0f, 100.0f, 100.0f),
.polygon = QUAD(49.0f, 51.0f, 99.0f, 99.0f),
.clipped = QUAD(50.0f, 51.0f, 99.0f, 99.0f),
.clipped_n = 4,
},
/* Quad right edge outside of box. */
{
.aligned = false,
.box = BOX (50.0f, 50.0f, 100.0f, 100.0f),
.polygon = QUAD(51.0f, 51.0f, 101.0f, 99.0f),
.clipped = QUAD(51.0f, 51.0f, 100.0f, 99.0f),
.clipped_n = 4,
},
/* Rotated quad with edges adjacent to box corners. */
{
.aligned = false,
.box = BOX(50.0f, 50.0f, 100.0f, 100.0f),
.polygon = {{ 25.0f, 75.0f}, {75.0f, 25.0f},
{125.0f, 75.0f}, {75.0f, 125.0f}},
.clipped = QUAD(50.0f, 50.0f, 100.0f, 100.0f),
.clipped_n = 4,
},
/* Rotated quad with edges cutting out box corners. */
{
.aligned = false,
.box = BOX(50.0f, 50.0f, 100.0f, 100.0f),
.polygon = {{ 37.5f, 75.0f}, { 75.0f, 37.5f},
{112.5f, 75.0f}, { 75.0f, 112.5f}},
.clipped = {{ 62.5f, 50.0f}, { 87.5f, 50.0f},
{100.0f, 62.5f}, {100.0f, 87.5f},
{ 87.5f, 100.0f}, { 62.5f, 100.0f},
{ 50.0f, 87.5f}, { 50.0f, 62.5f}},
.clipped_n = 8,
},
/* Same as above using counter-clockwise winding. */
{
.aligned = false,
.box = BOX(50.0f, 50.0f, 100.0f, 100.0f),
.polygon = {{ 37.5f, 75.0f}, { 75.0f, 112.5f},
{112.5f, 75.0f}, { 75.0f, 37.5f}},
.clipped = {{ 62.5f, 50.0f}, { 50.0f, 62.5f},
{ 50.0f, 87.5f}, { 62.5f, 100.0f},
{ 87.5f, 100.0f}, {100.0f, 87.5f},
{100.0f, 62.5f}, { 87.5f, 50.0f}},
.clipped_n = 8,
},
/* Miscellaneous cases: */
/* Box intersects entire same size aligned quad. */