Differential D6714 Diff 21269 source/blender/draw/engines/basic/shaders/conservative_depth_geom.glsl

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source/blender/draw/engines/basic/shaders/conservative_depth_geom.glsl

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				/* Adaptation of Conservative Rasterization
				* from GPU Gems 2
				* Using method 2.
				* https://developer.nvidia.com/gpugems/gpugems2/part-v-image-oriented-computing/chapter-42-conservative-rasterization
				*/

				layout(triangles) in;
				layout(triangle_strip, max_vertices = 3) out;

				RESOURCE_ID_VARYING

				uniform vec2 sizeViewport;
				uniform vec2 sizeViewportInv;

				flat out vec4 bbox;

				#define THRESHOLD 0.0000125
				#define FLT_MAX 9999999999999.0
				campbellbartonUnsubmitted Not Done Inline Actions Suggest calling this `BOUNDS_MAX` or similar, otherwise set to `3.40282347E+38F`. campbellbarton: Suggest calling this `BOUNDS_MAX` or similar, otherwise set to `3.40282347E+38F`.

				/**
				* Adds a new point to the bounding box. This method can be simplified if orthogonal
				* projection is assumed
				*/
				void bbox_min_max(vec4 pos, inout vec4 bbox)
				{
				if (pos.w < 0) {
				bbox.xy = min(bbox.xy, pos.xy);
				bbox.zw = max(bbox.zw, pos.xy);
				}
				else {
				bbox.xy = min(bbox.xy, pos.xy / pos.w);
				bbox.zw = max(bbox.zw, pos.xy / pos.w);
				}
				}

				void main()
				{
				vec4 curr_pos, prev_pos, next_pos;
				campbellbartonUnsubmitted Not Done Inline Actions Unused variables. campbellbarton: Unused variables.

				/* Compute the screen space bounding box of the triangle. */
				bbox = vec4(FLT_MAX, FLT_MAX, -FLT_MAX, -FLT_MAX);
				bbox_min_max(gl_in[0].gl_Position, bbox);
				bbox_min_max(gl_in[1].gl_Position, bbox);
				bbox_min_max(gl_in[2].gl_Position, bbox);
				/* Convert to pixel space and enlarge the BBox. */
				bbox = (bbox * 0.5 + 0.5) * sizeViewport.xyxy;
				bbox += vec4(-1.0, -1.0, 1.0, 1.0);

				for (int i = 0; i < 3; i++) {
				prev_pos = gl_in[(i + 2) % 3].gl_Position;
				curr_pos = gl_in[(i + 3) % 3].gl_Position;
				next_pos = gl_in[(i + 4) % 3].gl_Position;

				/* Compute the (x,y,w,d) triangle plane. */
				vec4 p_plane;
				campbellbartonUnsubmitted Not Done Inline Actions Could use define for the constant. campbellbarton: Could use define for the constant.
				p_plane.xyz = normalize(cross(curr_pos.xyw - prev_pos.xyw, next_pos.xyw - prev_pos.xyw));
				p_plane.w = -dot(p_plane.xyz, prev_pos.xyw);

				vec3 plane[2];
				plane[0] = cross(curr_pos.xyw - prev_pos.xyw, prev_pos.xyw);
				plane[1] = cross(next_pos.xyw - curr_pos.xyw, curr_pos.xyw);

				/* Test if the triangle is "almost backfacing" to avoid precision issues. */
				if (dot(curr_pos.xyw, p_plane.xyz) < THRESHOLD) {
				gl_Position = curr_pos;
				/* HACK: Fix cases where the triangle is parallel to the view
				* by deforming the triangle slightly. */
				gl_Position.xy += sizeViewportInv.xy * gl_Position.w * ((i % 2 == 0) ? -1.0 : 1.0);
				}
				else {
				/* Push the planes back enough to enclose the sample points of all pixels the triangle
				* intersects. The pushfactor is dependant on the slope (x,y). */
				plane[0].z -= dot(sizeViewportInv, abs(plane[0].xy));
				plane[1].z -= dot(sizeViewportInv, abs(plane[1].xy));

				/* Compute the intersection point of the two planes.
				* Gives us the final position of the vertex. */
				gl_Position.xyw = cross(plane[0], plane[1]);
				gl_Position /= abs(gl_Position.w);
				gl_Position.z = 1;
				}

				#ifdef USE_WORLD_CLIP_PLANES
				world_clip_planes_set_clip_distance(gl_in[i].gl_ClipDistance);
				#endif
				EmitVertex();
				}
				EndPrimitive();
				}
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