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-rw-r--r--src/gallium/drivers/llvmpipe/lp_setup.c10
-rw-r--r--src/gallium/drivers/llvmpipe/lp_setup_context.h1
-rw-r--r--src/gallium/drivers/llvmpipe/lp_setup_tri.c175
3 files changed, 186 insertions, 0 deletions
diff --git a/src/gallium/drivers/llvmpipe/lp_setup.c b/src/gallium/drivers/llvmpipe/lp_setup.c
index 299fd65ff06..c119395a9d6 100644
--- a/src/gallium/drivers/llvmpipe/lp_setup.c
+++ b/src/gallium/drivers/llvmpipe/lp_setup.c
@@ -1010,6 +1010,16 @@ try_update_scene_state( struct lp_setup_context *setup )
u_rect_possible_intersection(&setup->scissor,
&setup->draw_region);
}
+ /* If the framebuffer is large we have to think about fixed-point
+ * integer overflow. For 2K by 2K images, coordinates need 15 bits
+ * (2^11 + 4 subpixel bits). The product of two such numbers would
+ * use 30 bits. Any larger and we could overflow a 32-bit int.
+ *
+ * To cope with this problem we check if triangles are large and
+ * subdivide them if needed.
+ */
+ setup->subdivide_large_triangles = (setup->fb.width > 2048 &&
+ setup->fb.height > 2048);
}
setup->dirty = 0;
diff --git a/src/gallium/drivers/llvmpipe/lp_setup_context.h b/src/gallium/drivers/llvmpipe/lp_setup_context.h
index 0e2de648a91..b72831bf0e4 100644
--- a/src/gallium/drivers/llvmpipe/lp_setup_context.h
+++ b/src/gallium/drivers/llvmpipe/lp_setup_context.h
@@ -91,6 +91,7 @@ struct lp_setup_context
struct lp_fence *last_fence;
struct llvmpipe_query *active_query[PIPE_QUERY_TYPES];
+ boolean subdivide_large_triangles;
boolean flatshade_first;
boolean ccw_is_frontface;
boolean scissor_test;
diff --git a/src/gallium/drivers/llvmpipe/lp_setup_tri.c b/src/gallium/drivers/llvmpipe/lp_setup_tri.c
index 45ac6a79ada..cf3d536eb1d 100644
--- a/src/gallium/drivers/llvmpipe/lp_setup_tri.c
+++ b/src/gallium/drivers/llvmpipe/lp_setup_tri.c
@@ -865,6 +865,166 @@ rotate_fixed_position_12( struct fixed_position* position )
}
+typedef void (*triangle_func_t)(struct lp_setup_context *setup,
+ const float (*v0)[4],
+ const float (*v1)[4],
+ const float (*v2)[4]);
+
+
+/**
+ * Subdivide this triangle by bisecting edge (v0, v1).
+ * \param pv the provoking vertex (must = v0 or v1 or v2)
+ */
+static void
+subdiv_tri(struct lp_setup_context *setup,
+ const float (*v0)[4],
+ const float (*v1)[4],
+ const float (*v2)[4],
+ const float (*pv)[4],
+ triangle_func_t tri)
+{
+ unsigned n = setup->fs.current.variant->shader->info.base.num_inputs + 1;
+ const struct lp_shader_input *inputs =
+ setup->fs.current.variant->shader->inputs;
+ float vmid[PIPE_MAX_ATTRIBS][4];
+ const float (*vm)[4] = (const float (*)[4]) vmid;
+ unsigned i;
+ float w0, w1, wm;
+ boolean flatshade = setup->fs.current.variant->key.flatshade;
+
+ /* find position midpoint (attrib[0] = position) */
+ vmid[0][0] = 0.5f * (v1[0][0] + v0[0][0]);
+ vmid[0][1] = 0.5f * (v1[0][1] + v0[0][1]);
+ vmid[0][2] = 0.5f * (v1[0][2] + v0[0][2]);
+ vmid[0][3] = 0.5f * (v1[0][3] + v0[0][3]);
+
+ w0 = v0[0][3];
+ w1 = v1[0][3];
+ wm = vmid[0][3];
+
+ /* interpolate other attributes */
+ for (i = 1; i < n; i++) {
+ if ((inputs[i - 1].interp == LP_INTERP_COLOR && flatshade) ||
+ inputs[i - 1].interp == LP_INTERP_CONSTANT) {
+ /* copy the provoking vertex's attribute */
+ vmid[i][0] = pv[i][0];
+ vmid[i][1] = pv[i][1];
+ vmid[i][2] = pv[i][2];
+ vmid[i][3] = pv[i][3];
+ }
+ else {
+ /* interpolate with perspective correction (for linear too) */
+ vmid[i][0] = 0.5f * (v1[i][0] * w1 + v0[i][0] * w0) / wm;
+ vmid[i][1] = 0.5f * (v1[i][1] * w1 + v0[i][1] * w0) / wm;
+ vmid[i][2] = 0.5f * (v1[i][2] * w1 + v0[i][2] * w0) / wm;
+ vmid[i][3] = 0.5f * (v1[i][3] * w1 + v0[i][3] * w0) / wm;
+ }
+ }
+
+ /* handling flat shading and first vs. last provoking vertex is a
+ * little tricky...
+ */
+ if (pv == v0) {
+ if (setup->flatshade_first) {
+ /* first vertex must be v0 or vm */
+ tri(setup, v0, vm, v2);
+ tri(setup, vm, v1, v2);
+ }
+ else {
+ /* last vertex must be v0 or vm */
+ tri(setup, vm, v2, v0);
+ tri(setup, v1, v2, vm);
+ }
+ }
+ else if (pv == v1) {
+ if (setup->flatshade_first) {
+ tri(setup, vm, v2, v0);
+ tri(setup, v1, v2, vm);
+ }
+ else {
+ tri(setup, v2, v0, vm);
+ tri(setup, v2, vm, v1);
+ }
+ }
+ else {
+ if (setup->flatshade_first) {
+ tri(setup, v2, v0, vm);
+ tri(setup, v2, vm, v1);
+ }
+ else {
+ tri(setup, v0, vm, v2);
+ tri(setup, vm, v1, v2);
+ }
+ }
+}
+
+
+/**
+ * Check the lengths of the edges of the triangle. If any edge is too
+ * long, subdivide the longest edge and draw two sub-triangles.
+ * Note: this may be called recursively.
+ * \return TRUE if triangle was subdivided, FALSE otherwise
+ */
+static boolean
+check_subdivide_triangle(struct lp_setup_context *setup,
+ const float (*v0)[4],
+ const float (*v1)[4],
+ const float (*v2)[4],
+ triangle_func_t tri)
+{
+ const float maxLen = 2048.0f; /* longest permissible edge, in pixels */
+ float dx10, dy10, len10;
+ float dx21, dy21, len21;
+ float dx02, dy02, len02;
+ const float (*pv)[4] = setup->flatshade_first ? v0 : v2;
+
+ /* compute lengths of triangle edges, squared */
+ dx10 = v1[0][0] - v0[0][0];
+ dy10 = v1[0][1] - v0[0][1];
+ len10 = dx10 * dx10 + dy10 * dy10;
+
+ dx21 = v2[0][0] - v1[0][0];
+ dy21 = v2[0][1] - v1[0][1];
+ len21 = dx21 * dx21 + dy21 * dy21;
+
+ dx02 = v0[0][0] - v2[0][0];
+ dy02 = v0[0][1] - v2[0][1];
+ len02 = dx02 * dx02 + dy02 * dy02;
+
+ /* Look for longest the edge that's longer than maxLen. If we find
+ * such an edge, split the triangle using the midpoint of that edge.
+ * Note: it's important to split the longest edge, not just any edge
+ * that's longer than maxLen. Otherwise, we can get into a degenerate
+ * situation and recurse indefinitely.
+ */
+ if (len10 > maxLen * maxLen &&
+ len10 >= len21 &&
+ len10 >= len02) {
+ /* subdivide v0, v1 edge */
+ subdiv_tri(setup, v0, v1, v2, pv, tri);
+ return TRUE;
+ }
+
+ if (len21 > maxLen * maxLen &&
+ len21 >= len10 &&
+ len21 >= len02) {
+ /* subdivide v1, v2 edge */
+ subdiv_tri(setup, v1, v2, v0, pv, tri);
+ return TRUE;
+ }
+
+ if (len02 > maxLen * maxLen &&
+ len02 >= len21 &&
+ len02 >= len10) {
+ /* subdivide v2, v0 edge */
+ subdiv_tri(setup, v2, v0, v1, pv, tri);
+ return TRUE;
+ }
+
+ return FALSE;
+}
+
+
/**
* Draw triangle if it's CW, cull otherwise.
*/
@@ -874,6 +1034,11 @@ static void triangle_cw( struct lp_setup_context *setup,
const float (*v2)[4] )
{
struct fixed_position position;
+
+ if (setup->subdivide_large_triangles &&
+ check_subdivide_triangle(setup, v0, v1, v2, triangle_cw))
+ return;
+
calc_fixed_position(setup, &position, v0, v1, v2);
if (position.area < 0) {
@@ -894,6 +1059,11 @@ static void triangle_ccw( struct lp_setup_context *setup,
const float (*v2)[4])
{
struct fixed_position position;
+
+ if (setup->subdivide_large_triangles &&
+ check_subdivide_triangle(setup, v0, v1, v2, triangle_ccw))
+ return;
+
calc_fixed_position(setup, &position, v0, v1, v2);
if (position.area > 0)
@@ -909,6 +1079,11 @@ static void triangle_both( struct lp_setup_context *setup,
const float (*v2)[4] )
{
struct fixed_position position;
+
+ if (setup->subdivide_large_triangles &&
+ check_subdivide_triangle(setup, v0, v1, v2, triangle_both))
+ return;
+
calc_fixed_position(setup, &position, v0, v1, v2);
if (0) {
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-20 12:11:52 +0000