compositor: Move surface repaint code to gles2-renderer.c
diff --git a/src/gles2-renderer.c b/src/gles2-renderer.c
index e4598c9..14dcf64 100644
--- a/src/gles2-renderer.c
+++ b/src/gles2-renderer.c
@@ -20,6 +20,8 @@
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
+#include <stdlib.h>
+
#include "compositor.h"
static const char *
@@ -58,6 +60,551 @@
egl_error_string(code), (long)code);
}
+#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)
+#define sign(x) ((x) >= 0)
+
+static int
+calculate_edges(struct weston_surface *es, pixman_box32_t *rect,
+ pixman_box32_t *surf_rect, GLfloat *ex, GLfloat *ey)
+{
+ int i, n = 0;
+ GLfloat min_x, max_x, min_y, max_y;
+ GLfloat x[4] = {
+ surf_rect->x1, surf_rect->x2, surf_rect->x2, surf_rect->x1,
+ };
+ GLfloat y[4] = {
+ surf_rect->y1, surf_rect->y1, surf_rect->y2, surf_rect->y2,
+ };
+ GLfloat cx1 = rect->x1;
+ GLfloat cx2 = rect->x2;
+ GLfloat cy1 = rect->y1;
+ GLfloat cy2 = rect->y2;
+
+ GLfloat dist_squared(GLfloat x1, GLfloat y1, GLfloat x2, GLfloat y2)
+ {
+ GLfloat dx = (x1 - x2);
+ GLfloat dy = (y1 - y2);
+ return dx * dx + dy * dy;
+ }
+
+ void append_vertex(GLfloat x, GLfloat y)
+ {
+ /* don't emit duplicate vertices: */
+ if ((n > 0) && (ex[n-1] == x) && (ey[n-1] == y))
+ return;
+ ex[n] = x;
+ ey[n] = y;
+ n++;
+ }
+
+ /* transform surface to screen space: */
+ for (i = 0; i < 4; i++)
+ weston_surface_to_global_float(es, x[i], y[i], &x[i], &y[i]);
+
+ /* find bounding box: */
+ min_x = max_x = x[0];
+ min_y = max_y = y[0];
+
+ for (i = 1; i < 4; i++) {
+ min_x = min(min_x, x[i]);
+ max_x = max(max_x, x[i]);
+ min_y = min(min_y, y[i]);
+ max_y = max(max_y, y[i]);
+ }
+
+ /* First, simple bounding box check to discard early transformed
+ * surface rects that do not intersect with the clip region:
+ */
+ if ((min_x > cx2) || (max_x < cx1) ||
+ (min_y > cy2) || (max_y < cy1))
+ return 0;
+
+ /* Simple case, bounding box edges are parallel to surface edges,
+ * there will be only four edges. We just need to clip the surface
+ * vertices to the clip rect bounds:
+ */
+ if (!es->transform.enabled) {
+ for (i = 0; i < 4; i++) {
+ ex[n] = clip(x[i], cx1, cx2);
+ ey[n] = clip(y[i], cy1, cy2);
+ n++;
+ }
+ return 4;
+ }
+
+ /* Hard case, transformation applied. We need to find the vertices
+ * of the shape that is the intersection of the clip rect and
+ * transformed surface. This can be anything from 3 to 8 sides.
+ *
+ * Observation: all the resulting vertices will be the intersection
+ * points of the transformed surface and the clip rect, plus the
+ * vertices of the clip rect which are enclosed by the transformed
+ * surface and the vertices of the transformed surface which are
+ * enclosed by the clip rect.
+ *
+ * Observation: there will be zero, one, or two resulting vertices
+ * for each edge of the src rect.
+ *
+ * Loop over four edges of the transformed rect:
+ */
+ for (i = 0; i < 4; i++) {
+ GLfloat x1, y1, x2, y2;
+ int last_n = n;
+
+ x1 = x[i];
+ y1 = y[i];
+
+ /* if this vertex is contained in the clip rect, use it as-is: */
+ if ((cx1 <= x1) && (x1 <= cx2) &&
+ (cy1 <= y1) && (y1 <= cy2))
+ append_vertex(x1, y1);
+
+ /* for remaining, we consider the point as part of a line: */
+ x2 = x[(i+1) % 4];
+ y2 = y[(i+1) % 4];
+
+ if (x1 == x2) {
+ append_vertex(clip(x1, cx1, cx2), clip(y1, cy1, cy2));
+ append_vertex(clip(x2, cx1, cx2), clip(y2, cy1, cy2));
+ } else if (y1 == y2) {
+ append_vertex(clip(x1, cx1, cx2), clip(y1, cy1, cy2));
+ append_vertex(clip(x2, cx1, cx2), clip(y2, cy1, cy2));
+ } else {
+ GLfloat m, c, p;
+ GLfloat tx[2], ty[2];
+ int tn = 0;
+
+ int intersect_horiz(GLfloat y, GLfloat *p)
+ {
+ GLfloat x;
+
+ /* if y does not lie between y1 and y2, no
+ * intersection possible
+ */
+ if (sign(y-y1) == sign(y-y2))
+ return 0;
+
+ x = (y - c) / m;
+
+ /* if x does not lie between cx1 and cx2, no
+ * intersection:
+ */
+ if (sign(x-cx1) == sign(x-cx2))
+ return 0;
+
+ *p = x;
+ return 1;
+ }
+
+ int intersect_vert(GLfloat x, GLfloat *p)
+ {
+ GLfloat y;
+
+ if (sign(x-x1) == sign(x-x2))
+ return 0;
+
+ y = m * x + c;
+
+ if (sign(y-cy1) == sign(y-cy2))
+ return 0;
+
+ *p = y;
+ return 1;
+ }
+
+ /* y = mx + c */
+ m = (y2 - y1) / (x2 - x1);
+ c = y1 - m * x1;
+
+ /* check for up to two intersections with the four edges
+ * of the clip rect. Note that we don't know the orientation
+ * of the transformed surface wrt. the clip rect. So if when
+ * there are two intersection points, we need to put the one
+ * closest to x1,y1 first:
+ */
+
+ /* check top clip rect edge: */
+ if (intersect_horiz(cy1, &p)) {
+ ty[tn] = cy1;
+ tx[tn] = p;
+ tn++;
+ }
+
+ /* check right clip rect edge: */
+ if (intersect_vert(cx2, &p)) {
+ ty[tn] = p;
+ tx[tn] = cx2;
+ tn++;
+ if (tn == 2)
+ goto edge_check_done;
+ }
+
+ /* check bottom clip rect edge: */
+ if (intersect_horiz(cy2, &p)) {
+ ty[tn] = cy2;
+ tx[tn] = p;
+ tn++;
+ if (tn == 2)
+ goto edge_check_done;
+ }
+
+ /* check left clip rect edge: */
+ if (intersect_vert(cx1, &p)) {
+ ty[tn] = p;
+ tx[tn] = cx1;
+ tn++;
+ }
+
+edge_check_done:
+ if (tn == 1) {
+ append_vertex(tx[0], ty[0]);
+ } else if (tn == 2) {
+ if (dist_squared(x1, y1, tx[0], ty[0]) <
+ dist_squared(x1, y1, tx[1], ty[1])) {
+ append_vertex(tx[0], ty[0]);
+ append_vertex(tx[1], ty[1]);
+ } else {
+ append_vertex(tx[1], ty[1]);
+ append_vertex(tx[0], ty[0]);
+ }
+ }
+
+ if (n == last_n) {
+ GLfloat best_x=0, best_y=0;
+ uint32_t d, best_d = (unsigned int)-1; /* distance squared */
+ uint32_t max_d = dist_squared(x2, y2,
+ x[(i+2) % 4], y[(i+2) % 4]);
+
+ /* if there are no vertices on this line, it could be that
+ * there is a vertex of the clip rect that is enclosed by
+ * the transformed surface. Find the vertex of the clip
+ * rect that is reached by the shortest line perpendicular
+ * to the current edge, if any.
+ *
+ * slope of perpendicular is 1/m, so
+ *
+ * cy = -cx/m + c2
+ * c2 = cy + cx/m
+ *
+ */
+
+ int perp_intersect(GLfloat cx, GLfloat cy, uint32_t *d)
+ {
+ GLfloat c2 = cy + cx/m;
+ GLfloat x = (c2 - c) / (m + 1/m);
+
+ /* if the x position of the intersection of the
+ * perpendicular with the transformed edge does
+ * not lie within the bounds of the edge, then
+ * no intersection:
+ */
+ if (sign(x-x1) == sign(x-x2))
+ return 0;
+
+ *d = dist_squared(cx, cy, x, (m * x) + c);
+
+ /* if intersection distance is further away than
+ * opposite edge of surface region, it is invalid:
+ */
+ if (*d > max_d)
+ return 0;
+
+ return 1;
+ }
+
+ if (perp_intersect(cx1, cy1, &d)) {
+ best_x = cx1;
+ best_y = cy1;
+ best_d = d;
+ }
+
+ if (perp_intersect(cx1, cy2, &d) && (d < best_d)) {
+ best_x = cx1;
+ best_y = cy2;
+ best_d = d;
+ }
+
+ if (perp_intersect(cx2, cy2, &d) && (d < best_d)) {
+ best_x = cx2;
+ best_y = cy2;
+ best_d = d;
+ }
+
+ if (perp_intersect(cx2, cy1, &d) && (d < best_d)) {
+ best_x = cx2;
+ best_y = cy1;
+ best_d = d;
+ }
+
+ if (best_d != (unsigned int)-1) // XXX can this happen?
+ append_vertex(best_x, best_y);
+ }
+ }
+
+ }
+
+ return n;
+}
+
+static int
+texture_region(struct weston_surface *es, pixman_region32_t *region,
+ pixman_region32_t *surf_region)
+{
+ struct weston_compositor *ec = es->compositor;
+ GLfloat *v, inv_width, inv_height;
+ unsigned int *vtxcnt, nvtx = 0;
+ pixman_box32_t *rects, *surf_rects;
+ int i, j, k, nrects, nsurf;
+
+ rects = pixman_region32_rectangles(region, &nrects);
+ surf_rects = pixman_region32_rectangles(surf_region, &nsurf);
+
+ /* worst case we can have 8 vertices per rect (ie. clipped into
+ * an octagon):
+ */
+ v = wl_array_add(&ec->vertices, nrects * nsurf * 8 * 4 * sizeof *v);
+ vtxcnt = wl_array_add(&ec->vtxcnt, nrects * nsurf * sizeof *vtxcnt);
+
+ inv_width = 1.0 / es->pitch;
+ inv_height = 1.0 / es->geometry.height;
+
+ for (i = 0; i < nrects; i++) {
+ pixman_box32_t *rect = &rects[i];
+ for (j = 0; j < nsurf; j++) {
+ pixman_box32_t *surf_rect = &surf_rects[j];
+ GLfloat sx, sy;
+ GLfloat ex[8], ey[8]; /* edge points in screen space */
+ int n;
+
+ /* The transformed surface, after clipping to the clip region,
+ * can have as many as eight sides, emitted as a triangle-fan.
+ * The first vertex in the triangle fan can be chosen arbitrarily,
+ * since the area is guaranteed to be convex.
+ *
+ * If a corner of the transformed surface falls outside of the
+ * clip region, instead of emitting one vertex for the corner
+ * of the surface, up to two are emitted for two corresponding
+ * intersection point(s) between the surface and the clip region.
+ *
+ * To do this, we first calculate the (up to eight) points that
+ * form the intersection of the clip rect and the transformed
+ * surface.
+ */
+ n = calculate_edges(es, rect, surf_rect, ex, ey);
+ if (n < 3)
+ continue;
+
+ /* emit edge points: */
+ for (k = 0; k < n; k++) {
+ weston_surface_from_global_float(es, ex[k], ey[k], &sx, &sy);
+ /* position: */
+ *(v++) = ex[k];
+ *(v++) = ey[k];
+ /* texcoord: */
+ *(v++) = sx * inv_width;
+ *(v++) = sy * inv_height;
+ }
+
+ vtxcnt[nvtx++] = n;
+ }
+ }
+
+ return nvtx;
+}
+
+static void
+triangle_fan_debug(struct weston_surface *surface, int first, int count)
+{
+ struct weston_compositor *compositor = surface->compositor;
+ int i;
+ GLushort *buffer;
+ GLushort *index;
+ int nelems;
+ static int color_idx = 0;
+ static const GLfloat color[][4] = {
+ { 1.0, 0.0, 0.0, 1.0 },
+ { 0.0, 1.0, 0.0, 1.0 },
+ { 0.0, 0.0, 1.0, 1.0 },
+ { 1.0, 1.0, 1.0, 1.0 },
+ };
+
+ nelems = (count - 1 + count - 2) * 2;
+
+ buffer = malloc(sizeof(GLushort) * nelems);
+ index = buffer;
+
+ for (i = 1; i < count; i++) {
+ *index++ = first;
+ *index++ = first + i;
+ }
+
+ for (i = 2; i < count; i++) {
+ *index++ = first + i - 1;
+ *index++ = first + i;
+ }
+
+ glUseProgram(compositor->solid_shader.program);
+ glUniform4fv(compositor->solid_shader.color_uniform, 1,
+ color[color_idx++ % ARRAY_LENGTH(color)]);
+ glDrawElements(GL_LINES, nelems, GL_UNSIGNED_SHORT, buffer);
+ glUseProgram(compositor->current_shader->program);
+ free(buffer);
+}
+
+static void
+repaint_region(struct weston_surface *es, pixman_region32_t *region,
+ pixman_region32_t *surf_region)
+{
+ struct weston_compositor *ec = es->compositor;
+ GLfloat *v;
+ unsigned int *vtxcnt;
+ int i, first, nfans;
+
+ /* The final region to be painted is the intersection of
+ * 'region' and 'surf_region'. However, 'region' is in the global
+ * coordinates, and 'surf_region' is in the surface-local
+ * coordinates. texture_region() will iterate over all pairs of
+ * rectangles from both regions, compute the intersection
+ * polygon for each pair, and store it as a triangle fan if
+ * it has a non-zero area (at least 3 vertices, actually).
+ */
+ nfans = texture_region(es, region, surf_region);
+
+ v = ec->vertices.data;
+ vtxcnt = ec->vtxcnt.data;
+
+ /* position: */
+ glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4 * sizeof *v, &v[0]);
+ glEnableVertexAttribArray(0);
+
+ /* texcoord: */
+ glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 4 * sizeof *v, &v[2]);
+ glEnableVertexAttribArray(1);
+
+ for (i = 0, first = 0; i < nfans; i++) {
+ glDrawArrays(GL_TRIANGLE_FAN, first, vtxcnt[i]);
+ if (ec->fan_debug)
+ triangle_fan_debug(es, first, vtxcnt[i]);
+ first += vtxcnt[i];
+ }
+
+ glDisableVertexAttribArray(1);
+ glDisableVertexAttribArray(0);
+
+ ec->vertices.size = 0;
+ ec->vtxcnt.size = 0;
+}
+
+static void
+weston_compositor_use_shader(struct weston_compositor *compositor,
+ struct weston_shader *shader)
+{
+ if (compositor->current_shader == shader)
+ return;
+
+ glUseProgram(shader->program);
+ compositor->current_shader = shader;
+}
+
+static void
+weston_shader_uniforms(struct weston_shader *shader,
+ struct weston_surface *surface,
+ struct weston_output *output)
+{
+ int i;
+
+ glUniformMatrix4fv(shader->proj_uniform,
+ 1, GL_FALSE, output->matrix.d);
+ glUniform4fv(shader->color_uniform, 1, surface->color);
+ glUniform1f(shader->alpha_uniform, surface->alpha);
+
+ for (i = 0; i < surface->num_textures; i++)
+ glUniform1i(shader->tex_uniforms[i], i);
+}
+
+static void
+draw_surface(struct weston_surface *es, struct weston_output *output,
+ pixman_region32_t *damage) /* in global coordinates */
+{
+ struct weston_compositor *ec = es->compositor;
+ /* repaint bounding region in global coordinates: */
+ pixman_region32_t repaint;
+ /* non-opaque region in surface coordinates: */
+ pixman_region32_t surface_blend;
+ GLint filter;
+ int i;
+
+ pixman_region32_init(&repaint);
+ pixman_region32_intersect(&repaint,
+ &es->transform.boundingbox, damage);
+ pixman_region32_subtract(&repaint, &repaint, &es->clip);
+
+ if (!pixman_region32_not_empty(&repaint))
+ goto out;
+
+ pixman_region32_subtract(&ec->primary_plane.damage,
+ &ec->primary_plane.damage, &repaint);
+
+ glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
+
+ if (ec->fan_debug) {
+ weston_compositor_use_shader(ec, &ec->solid_shader);
+ weston_shader_uniforms(&ec->solid_shader, es, output);
+ }
+
+ weston_compositor_use_shader(ec, es->shader);
+ weston_shader_uniforms(es->shader, es, output);
+
+ if (es->transform.enabled || output->zoom.active)
+ filter = GL_LINEAR;
+ else
+ filter = GL_NEAREST;
+
+ for (i = 0; i < es->num_textures; i++) {
+ glActiveTexture(GL_TEXTURE0 + i);
+ glBindTexture(es->target, es->textures[i]);
+ glTexParameteri(es->target, GL_TEXTURE_MIN_FILTER, filter);
+ glTexParameteri(es->target, GL_TEXTURE_MAG_FILTER, filter);
+ }
+
+ /* blended region is whole surface minus opaque region: */
+ pixman_region32_init_rect(&surface_blend, 0, 0,
+ es->geometry.width, es->geometry.height);
+ pixman_region32_subtract(&surface_blend, &surface_blend, &es->opaque);
+
+ if (pixman_region32_not_empty(&es->opaque)) {
+ if (es->shader == &ec->texture_shader_rgba) {
+ /* Special case for RGBA textures with possibly
+ * bad data in alpha channel: use the shader
+ * that forces texture alpha = 1.0.
+ * Xwayland surfaces need this.
+ */
+ weston_compositor_use_shader(ec, &ec->texture_shader_rgbx);
+ weston_shader_uniforms(&ec->texture_shader_rgbx, es, output);
+ }
+
+ if (es->alpha < 1.0)
+ glEnable(GL_BLEND);
+ else
+ glDisable(GL_BLEND);
+
+ repaint_region(es, &repaint, &es->opaque);
+ }
+
+ if (pixman_region32_not_empty(&surface_blend)) {
+ weston_compositor_use_shader(ec, es->shader);
+ glEnable(GL_BLEND);
+ repaint_region(es, &repaint, &surface_blend);
+ }
+
+ pixman_region32_fini(&surface_blend);
+
+out:
+ pixman_region32_fini(&repaint);
+}
+
static void
repaint_surfaces(struct weston_output *output, pixman_region32_t *damage)
{
@@ -66,7 +613,7 @@
wl_list_for_each_reverse(surface, &compositor->surface_list, link)
if (surface->plane == &compositor->primary_plane)
- weston_surface_draw(surface, output, damage);
+ draw_surface(surface, output, damage);
}
WL_EXPORT void