From 06e089275d30a7803f6873cd55d1041356eb07ab Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ond=C5=99ej=20Majerech?= Date: Tue, 19 Aug 2014 15:59:44 +0200 Subject: [PATCH] Remove duplicated code from cliptest.c MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Signed-off-by: Ondřej Majerech Reviewed-by: Pekka Paalanen --- Makefile.am | 2 +- clients/cliptest.c | 293 +---------------------------------------------------- 2 files changed, 4 insertions(+), 291 deletions(-) diff --git a/Makefile.am b/Makefile.am index 191dcc9..8a27d44 100644 --- a/Makefile.am +++ b/Makefile.am @@ -476,7 +476,7 @@ weston_image_SOURCES = clients/image.c weston_image_LDADD = libtoytoolkit.la weston_image_CFLAGS = $(AM_CFLAGS) $(CLIENT_CFLAGS) -weston_cliptest_SOURCES = clients/cliptest.c +weston_cliptest_SOURCES = clients/cliptest.c src/vertex-clipping.c weston_cliptest_CFLAGS = $(AM_CFLAGS) $(CLIENT_CFLAGS) weston_cliptest_LDADD = libtoytoolkit.la diff --git a/clients/cliptest.c b/clients/cliptest.c index 907c5d4..af7bff1 100644 --- a/clients/cliptest.c +++ b/clients/cliptest.c @@ -49,6 +49,7 @@ #include #include +#include "src/vertex-clipping.h" #include "window.h" typedef float GLfloat; @@ -81,269 +82,6 @@ weston_surface_to_global_float(struct weston_surface *surface, *y = -g->s * sx + g->c * sy; } -/* ---------------------- copied begins -----------------------*/ - -struct polygon8 { - GLfloat x[8]; - GLfloat y[8]; - int n; -}; - -struct clip_context { - struct { - GLfloat x; - GLfloat y; - } prev; - - struct { - GLfloat x1, y1; - GLfloat x2, y2; - } clip; - - struct { - GLfloat *x; - GLfloat *y; - } vertices; -}; - -static GLfloat -float_difference(GLfloat a, GLfloat b) -{ - /* http://www.altdevblogaday.com/2012/02/22/comparing-floating-point-numbers-2012-edition/ */ - static const GLfloat max_diff = 4.0f * FLT_MIN; - static const GLfloat max_rel_diff = 4.0e-5; - GLfloat diff = a - b; - GLfloat adiff = fabsf(diff); - - if (adiff <= max_diff) - return 0.0f; - - a = fabsf(a); - b = fabsf(b); - if (adiff <= (a > b ? a : b) * max_rel_diff) - return 0.0f; - - return diff; -} - -/* A line segment (p1x, p1y)-(p2x, p2y) intersects the line x = x_arg. - * Compute the y coordinate of the intersection. - */ -static GLfloat -clip_intersect_y(GLfloat p1x, GLfloat p1y, GLfloat p2x, GLfloat p2y, - GLfloat x_arg) -{ - GLfloat a; - GLfloat diff = float_difference(p1x, p2x); - - /* Practically vertical line segment, yet the end points have already - * been determined to be on different sides of the line. Therefore - * the line segment is part of the line and intersects everywhere. - * Return the end point, so we use the whole line segment. - */ - if (diff == 0.0f) - return p2y; - - a = (x_arg - p2x) / diff; - return p2y + (p1y - p2y) * a; -} - -/* A line segment (p1x, p1y)-(p2x, p2y) intersects the line y = y_arg. - * Compute the x coordinate of the intersection. - */ -static GLfloat -clip_intersect_x(GLfloat p1x, GLfloat p1y, GLfloat p2x, GLfloat p2y, - GLfloat y_arg) -{ - GLfloat a; - GLfloat diff = float_difference(p1y, p2y); - - /* Practically horizontal line segment, yet the end points have already - * been determined to be on different sides of the line. Therefore - * the line segment is part of the line and intersects everywhere. - * Return the end point, so we use the whole line segment. - */ - if (diff == 0.0f) - return p2x; - - a = (y_arg - p2y) / diff; - return p2x + (p1x - p2x) * a; -} - -enum path_transition { - PATH_TRANSITION_OUT_TO_OUT = 0, - PATH_TRANSITION_OUT_TO_IN = 1, - PATH_TRANSITION_IN_TO_OUT = 2, - PATH_TRANSITION_IN_TO_IN = 3, -}; - -static void -clip_append_vertex(struct clip_context *ctx, GLfloat x, GLfloat y) -{ - *ctx->vertices.x++ = x; - *ctx->vertices.y++ = y; -} - -static enum path_transition -path_transition_left_edge(struct clip_context *ctx, GLfloat x, GLfloat y) -{ - return ((ctx->prev.x >= ctx->clip.x1) << 1) | (x >= ctx->clip.x1); -} - -static enum path_transition -path_transition_right_edge(struct clip_context *ctx, GLfloat x, GLfloat y) -{ - return ((ctx->prev.x < ctx->clip.x2) << 1) | (x < ctx->clip.x2); -} - -static enum path_transition -path_transition_top_edge(struct clip_context *ctx, GLfloat x, GLfloat y) -{ - return ((ctx->prev.y >= ctx->clip.y1) << 1) | (y >= ctx->clip.y1); -} - -static enum path_transition -path_transition_bottom_edge(struct clip_context *ctx, GLfloat x, GLfloat y) -{ - return ((ctx->prev.y < ctx->clip.y2) << 1) | (y < ctx->clip.y2); -} - -static void -clip_polygon_leftright(struct clip_context *ctx, - enum path_transition transition, - GLfloat x, GLfloat y, GLfloat clip_x) -{ - GLfloat yi; - - switch (transition) { - case PATH_TRANSITION_IN_TO_IN: - clip_append_vertex(ctx, x, y); - break; - case PATH_TRANSITION_IN_TO_OUT: - yi = clip_intersect_y(ctx->prev.x, ctx->prev.y, x, y, clip_x); - clip_append_vertex(ctx, clip_x, yi); - break; - case PATH_TRANSITION_OUT_TO_IN: - yi = clip_intersect_y(ctx->prev.x, ctx->prev.y, x, y, clip_x); - clip_append_vertex(ctx, clip_x, yi); - clip_append_vertex(ctx, x, y); - break; - case PATH_TRANSITION_OUT_TO_OUT: - /* nothing */ - break; - default: - assert(0 && "bad enum path_transition"); - } - - ctx->prev.x = x; - ctx->prev.y = y; -} - -static void -clip_polygon_topbottom(struct clip_context *ctx, - enum path_transition transition, - GLfloat x, GLfloat y, GLfloat clip_y) -{ - GLfloat xi; - - switch (transition) { - case PATH_TRANSITION_IN_TO_IN: - clip_append_vertex(ctx, x, y); - break; - case PATH_TRANSITION_IN_TO_OUT: - xi = clip_intersect_x(ctx->prev.x, ctx->prev.y, x, y, clip_y); - clip_append_vertex(ctx, xi, clip_y); - break; - case PATH_TRANSITION_OUT_TO_IN: - xi = clip_intersect_x(ctx->prev.x, ctx->prev.y, x, y, clip_y); - clip_append_vertex(ctx, xi, clip_y); - clip_append_vertex(ctx, x, y); - break; - case PATH_TRANSITION_OUT_TO_OUT: - /* nothing */ - break; - default: - assert(0 && "bad enum path_transition"); - } - - ctx->prev.x = x; - ctx->prev.y = y; -} - -static void -clip_context_prepare(struct clip_context *ctx, const struct polygon8 *src, - GLfloat *dst_x, GLfloat *dst_y) -{ - ctx->prev.x = src->x[src->n - 1]; - ctx->prev.y = src->y[src->n - 1]; - ctx->vertices.x = dst_x; - ctx->vertices.y = dst_y; -} - -static int -clip_polygon_left(struct clip_context *ctx, const struct polygon8 *src, - GLfloat *dst_x, GLfloat *dst_y) -{ - enum path_transition trans; - int i; - - clip_context_prepare(ctx, src, dst_x, dst_y); - for (i = 0; i < src->n; i++) { - trans = path_transition_left_edge(ctx, src->x[i], src->y[i]); - clip_polygon_leftright(ctx, trans, src->x[i], src->y[i], - ctx->clip.x1); - } - return ctx->vertices.x - dst_x; -} - -static int -clip_polygon_right(struct clip_context *ctx, const struct polygon8 *src, - GLfloat *dst_x, GLfloat *dst_y) -{ - enum path_transition trans; - int i; - - clip_context_prepare(ctx, src, dst_x, dst_y); - for (i = 0; i < src->n; i++) { - trans = path_transition_right_edge(ctx, src->x[i], src->y[i]); - clip_polygon_leftright(ctx, trans, src->x[i], src->y[i], - ctx->clip.x2); - } - return ctx->vertices.x - dst_x; -} - -static int -clip_polygon_top(struct clip_context *ctx, const struct polygon8 *src, - GLfloat *dst_x, GLfloat *dst_y) -{ - enum path_transition trans; - int i; - - clip_context_prepare(ctx, src, dst_x, dst_y); - for (i = 0; i < src->n; i++) { - trans = path_transition_top_edge(ctx, src->x[i], src->y[i]); - clip_polygon_topbottom(ctx, trans, src->x[i], src->y[i], - ctx->clip.y1); - } - return ctx->vertices.x - dst_x; -} - -static int -clip_polygon_bottom(struct clip_context *ctx, const struct polygon8 *src, - GLfloat *dst_x, GLfloat *dst_y) -{ - enum path_transition trans; - int i; - - clip_context_prepare(ctx, src, dst_x, dst_y); - for (i = 0; i < src->n; i++) { - trans = path_transition_bottom_edge(ctx, src->x[i], src->y[i]); - clip_polygon_topbottom(ctx, trans, src->x[i], src->y[i], - ctx->clip.y2); - } - return ctx->vertices.x - dst_x; -} - #define max(a, b) (((a) > (b)) ? (a) : (b)) #define min(a, b) (((a) > (b)) ? (b) : (a)) #define clip(x, a, b) min(max(x, a), b) @@ -361,9 +99,8 @@ static int calculate_edges(struct weston_surface *es, pixman_box32_t *rect, pixman_box32_t *surf_rect, GLfloat *ex, GLfloat *ey) { - struct polygon8 polygon; struct clip_context ctx; - int i, n; + int i; GLfloat min_x, max_x, min_y, max_y; struct polygon8 surf = { { surf_rect->x1, surf_rect->x2, surf_rect->x2, surf_rect->x1 }, @@ -417,31 +154,7 @@ calculate_edges(struct weston_surface *es, pixman_box32_t *rect, * http://www.codeguru.com/cpp/misc/misc/graphics/article.php/c8965/Polygon-Clipping.htm * but without looking at any of that code. */ - polygon.n = clip_polygon_left(&ctx, &surf, polygon.x, polygon.y); - surf.n = clip_polygon_right(&ctx, &polygon, surf.x, surf.y); - polygon.n = clip_polygon_top(&ctx, &surf, polygon.x, polygon.y); - surf.n = clip_polygon_bottom(&ctx, &polygon, surf.x, surf.y); - - /* Get rid of duplicate vertices */ - ex[0] = surf.x[0]; - ey[0] = surf.y[0]; - n = 1; - for (i = 1; i < surf.n; i++) { - if (float_difference(ex[n - 1], surf.x[i]) == 0.0f && - float_difference(ey[n - 1], surf.y[i]) == 0.0f) - continue; - ex[n] = surf.x[i]; - ey[n] = surf.y[i]; - n++; - } - if (float_difference(ex[n - 1], surf.x[0]) == 0.0f && - float_difference(ey[n - 1], surf.y[0]) == 0.0f) - n--; - - if (n < 3) - return 0; - - return n; + return clip_transformed(&ctx, &surf, ex, ey); } -- 2.7.4