Wireframe: Refactor to use GL_LINES instead of triangles with alpha blend

This gets rid of the progressive fading of the edges as it does not work
with depth perception (sorting problem with alpha blending).

3 files changed, 50 insertions, 116 deletions

diff --git a/source/blender/draw/modes/overlay_mode.c b/source/blender/draw/modes/overlay_mode.c
index 550dfe0be7a..9ff8e2b30f1 100644
--- a/source/blender/draw/modes/overlay_mode.c
+++ b/source/blender/draw/modes/overlay_mode.c
@@ -55,7 +55,7 @@ typedef struct OVERLAY_PrivateData {
 	DRWShadingGroup *flat_wires_shgrp;
 	DRWShadingGroup *sculpt_wires_shgrp;
 	View3DOverlay overlay;
-	float wire_step_param[2];
+	float wire_step_param;
 	bool ghost_stencil_test;
 	bool show_overlays;
 } OVERLAY_PrivateData; /* Transient data */
@@ -127,9 +127,8 @@ static void overlay_engine_init(void *vedata)
 		});
 		sh_data->face_wireframe_sculpt = GPU_shader_create_from_arrays({
 		        .vert = (const char *[]){sh_cfg_data->lib, datatoc_overlay_face_wireframe_vert_glsl, NULL},
-		        .geom = (const char *[]){sh_cfg_data->lib, datatoc_overlay_face_wireframe_geom_glsl, NULL},
 		        .frag = (const char *[]){datatoc_overlay_face_wireframe_frag_glsl, NULL},
-		        .defs = (const char *[]){sh_cfg_data->def, "#define USE_SCULPT\n", NULL},
+		        .defs = (const char *[]){sh_cfg_data->def, NULL},
 		});
 	}
 }
@@ -179,7 +178,7 @@ static void overlay_cache_init(void *vedata)
 
 	{
 		/* Wireframe */
-		DRWState state = DRW_STATE_WRITE_COLOR | DRW_STATE_DEPTH_LESS_EQUAL | DRW_STATE_BLEND | DRW_STATE_FIRST_VERTEX_CONVENTION;
+		DRWState state = DRW_STATE_WRITE_COLOR | DRW_STATE_WRITE_DEPTH | DRW_STATE_DEPTH_LESS | DRW_STATE_FIRST_VERTEX_CONVENTION | DRW_STATE_OFFSET_NEGATIVE;
 		float wire_size = max_ff(0.0f, U.pixelsize - 1.0f) * 0.5f;
 
 		const bool use_select = (DRW_state_is_select() || DRW_state_is_depth());
@@ -200,7 +199,7 @@ static void overlay_cache_init(void *vedata)
 		}
 
 		g_data->face_wires_shgrp = DRW_shgroup_create(face_wires_sh, psl->face_wireframe_pass);
-		DRW_shgroup_uniform_vec2(g_data->face_wires_shgrp, "wireStepParam", g_data->wire_step_param, 1);
+		DRW_shgroup_uniform_float(g_data->face_wires_shgrp, "wireStepParam", &g_data->wire_step_param, 1);
 		if (rv3d->rflag & RV3D_CLIPPING) {
 			DRW_shgroup_world_clip_planes_from_rv3d(g_data->face_wires_shgrp, rv3d);
 		}
@@ -210,14 +209,7 @@ static void overlay_cache_init(void *vedata)
 			DRW_shgroup_uniform_float_copy(g_data->face_wires_shgrp, "wireSize", wire_size);
 		}
 
-		/* Control aspect of the falloff. */
-		const float sharpness = 4.0f;
-		/* Scale and bias: Adjust with wiredata encoding. (see mesh_batch_cache_create_edges_wireframe_data) */
-		const float decompress = (0xFF / (float)(0xFF - 0x20));
-		g_data->wire_step_param[0] = -sharpness * decompress;
-		g_data->wire_step_param[1] = decompress + sharpness * stl->g_data->overlay.wireframe_threshold;
-
-
+		g_data->wire_step_param = stl->g_data->overlay.wireframe_threshold - 254.0f / 255.0f;
 	}
 }
 
@@ -227,7 +219,6 @@ static void overlay_cache_populate(void *vedata, Object *ob)
 	OVERLAY_StorageList *stl = data->stl;
 	OVERLAY_PrivateData *pd = stl->g_data;
 	const DRWContextState *draw_ctx = DRW_context_state_get();
-	RegionView3D *rv3d = draw_ctx->rv3d;
 	View3D *v3d = draw_ctx->v3d;
 
 	if ((!pd->show_overlays) ||
@@ -266,14 +257,14 @@ static void overlay_cache_populate(void *vedata, Object *ob)
 		{
 			const bool is_active = (ob == draw_ctx->obact);
 			const bool is_sculpt_mode = is_active && (draw_ctx->object_mode & OB_MODE_SCULPT) != 0;
-			const bool all_wires = (pd->overlay.wireframe_threshold == 1.0f) ||
-			                       (ob->dtx & OB_DRAW_ALL_EDGES);
+			const bool all_wires = (ob->dtx & OB_DRAW_ALL_EDGES);
 			const bool is_wire = (ob->dt < OB_SOLID);
 			const int stencil_mask = (ob->dtx & OB_DRAWXRAY) ? 0x00 : 0xFF;
 			DRWShadingGroup *shgrp = NULL;
 
 			const float *rim_col = NULL;
 			const float *wire_col = NULL;
+
 			if (UNLIKELY(ob->base_flag & BASE_FROM_SET)) {
 				rim_col = G_draw.block.colorDupli;
 				wire_col = G_draw.block.colorDupli;
@@ -312,47 +303,29 @@ static void overlay_cache_populate(void *vedata, Object *ob)
 			}
 			BLI_assert(rim_col && wire_col);
 
-			/* This fixes only the biggest case which is a plane in ortho view. */
-			int flat_axis = 0;
-			bool is_flat_object_viewed_from_side = (
-			        (rv3d->persp == RV3D_ORTHO) &&
-			        DRW_object_is_flat(ob, &flat_axis) &&
-			        DRW_object_axis_orthogonal_to_view(ob, flat_axis));
-
-			if (is_flat_object_viewed_from_side && !is_sculpt_mode) {
-				/* Avoid losing flat objects when in ortho views (see T56549) */
-				struct GPUBatch *geom = DRW_cache_object_all_edges_get(ob);
-				if (geom) {
-					shgrp = pd->flat_wires_shgrp;
-					shgrp = DRW_shgroup_create_sub(shgrp);
+			struct GPUBatch *geom;
+			geom = DRW_cache_object_face_wireframe_get(ob);
+
+			if (geom || is_sculpt_mode) {
+				shgrp = (is_sculpt_mode) ? pd->sculpt_wires_shgrp : pd->face_wires_shgrp;
+				shgrp = DRW_shgroup_create_sub(shgrp);
+
+				static float all_wires_param = 10.0f;
+				DRW_shgroup_uniform_vec2(
+				        shgrp, "wireStepParam", (all_wires) ?
+				        &all_wires_param : &pd->wire_step_param, 1);
+
+				if (!(DRW_state_is_select() || DRW_state_is_depth())) {
 					DRW_shgroup_stencil_mask(shgrp, stencil_mask);
-					DRW_shgroup_call_object_add(shgrp, geom, ob);
-					DRW_shgroup_uniform_vec4(shgrp, "color", rim_col, 1);
+					DRW_shgroup_uniform_vec3(shgrp, "wireColor", wire_col, 1);
+					DRW_shgroup_uniform_vec3(shgrp, "rimColor", rim_col, 1);
 				}
-			}
-			else {
-				struct GPUBatch *geom = DRW_cache_object_face_wireframe_get(ob);
-				if (geom || is_sculpt_mode) {
-					shgrp = (is_sculpt_mode) ? pd->sculpt_wires_shgrp : pd->face_wires_shgrp;
-					shgrp = DRW_shgroup_create_sub(shgrp);
-
-					static float all_wires_params[2] = {0.0f, 10.0f}; /* Parameters for all wires */
-					DRW_shgroup_uniform_vec2(
-					        shgrp, "wireStepParam", (all_wires) ?
-					        all_wires_params : pd->wire_step_param, 1);
-
-					if (!(DRW_state_is_select() || DRW_state_is_depth())) {
-						DRW_shgroup_stencil_mask(shgrp, stencil_mask);
-						DRW_shgroup_uniform_vec3(shgrp, "wireColor", wire_col, 1);
-						DRW_shgroup_uniform_vec3(shgrp, "rimColor", rim_col, 1);
-					}
 
-					if (is_sculpt_mode) {
-						DRW_shgroup_call_sculpt_add(shgrp, ob, ob->obmat);
-					}
-					else {
-						DRW_shgroup_call_add(shgrp, geom, ob->obmat);
-					}
+				if (is_sculpt_mode) {
+					DRW_shgroup_call_sculpt_add(shgrp, ob, ob->obmat);
+				}
+				else {
+					DRW_shgroup_call_add(shgrp, geom, ob->obmat);
 				}
 			}
 			if (is_wire && shgrp != NULL) {
@@ -392,12 +365,18 @@ static void overlay_draw_scene(void *vedata)
 	OVERLAY_Data *data = vedata;
 	OVERLAY_PassList *psl = data->psl;
 	DefaultFramebufferList *dfbl = DRW_viewport_framebuffer_list_get();
+	DefaultTextureList *dtxl = DRW_viewport_texture_list_get();
 
 	if (DRW_state_is_fbo()) {
 		GPU_framebuffer_bind(dfbl->default_fb);
 	}
 	DRW_draw_pass(psl->face_orientation_pass);
+
+	MULTISAMPLE_SYNC_ENABLE(dfbl, dtxl);
+
 	DRW_draw_pass(psl->face_wireframe_pass);
+
+	MULTISAMPLE_SYNC_DISABLE(dfbl, dtxl);
 }
 
 static void overlay_engine_free(void)
diff --git a/source/blender/draw/modes/shaders/overlay_face_wireframe_frag.glsl b/source/blender/draw/modes/shaders/overlay_face_wireframe_frag.glsl
index cefd4eab2e3..1a984b2fbc6 100644
--- a/source/blender/draw/modes/shaders/overlay_face_wireframe_frag.glsl
+++ b/source/blender/draw/modes/shaders/overlay_face_wireframe_frag.glsl
@@ -1,41 +1,23 @@
+
 uniform vec3 wireColor;
 uniform vec3 rimColor;
 
+flat in float edgeSharpness;
 in float facing;
-in vec3 barycentric;
-flat in vec3 edgeSharpness;
 
 out vec4 fragColor;
 
-float max_v3(vec3 v) { return max(v.x, max(v.y, v.z)); }
-
-/* In pixels */
-uniform float wireSize = 0.0; /* Expands the core of the wire (part that is 100% wire color) */
-const float wire_smooth = 1.2; /* Smoothing distance after the 100% core. */
-
-/* Alpha constants could be exposed in the future. */
-const float front_alpha = 0.35;
-const float rim_alpha = 0.75;
-
 void main()
 {
-	vec3 dx = dFdx(barycentric);
-	vec3 dy = dFdy(barycentric);
-	vec3 d = vec3(
-		length(vec2(dx.x, dy.x)),
-		length(vec2(dx.y, dy.y)),
-		length(vec2(dx.z, dy.z))
-	);
-	vec3 dist_to_edge = barycentric / d;
-
-	vec3 fac = abs(dist_to_edge);
-
-	fac = smoothstep(wireSize + wire_smooth, wireSize, fac);
+	if (edgeSharpness < 0.0) {
+		discard;
+	}
 
-	float facing_clamped = clamp((gl_FrontFacing) ? facing : -facing, 0.0, 1.0);
+	float facing_clamped = clamp(abs(facing), 0.0, 1.0);
 
-	vec3 final_front_col = mix(rimColor, wireColor, 0.05);
-	fragColor = mix(vec4(rimColor, rim_alpha), vec4(final_front_col, front_alpha), facing_clamped);
+	vec3 final_front_col = mix(rimColor, wireColor, 0.4);
+	vec3 final_rim_col = mix(rimColor, wireColor, 0.1);
 
-	fragColor.a *= max_v3(fac * edgeSharpness);
+	fragColor.rgb = mix(final_rim_col, final_front_col, facing_clamped);
+	fragColor.a = 1.0f;
 }
diff --git a/source/blender/draw/modes/shaders/overlay_face_wireframe_vert.glsl b/source/blender/draw/modes/shaders/overlay_face_wireframe_vert.glsl
index 1ae204de60d..4e7560141f6 100644
--- a/source/blender/draw/modes/shaders/overlay_face_wireframe_vert.glsl
+++ b/source/blender/draw/modes/shaders/overlay_face_wireframe_vert.glsl
@@ -3,22 +3,11 @@ uniform mat4 ModelViewProjectionMatrix;
 uniform mat4 ModelMatrix;
 uniform mat3 NormalMatrix;
 
-uniform vec2 wireStepParam;
-
-vec3 get_edge_sharpness(vec3 wd)
-{
-	bvec3 do_edge = greaterThan(wd, vec3(0.0));
-	bvec3 force_edge = equal(wd, vec3(1.0));
-	wd = clamp(wireStepParam.x * wd + wireStepParam.y, 0.0, 1.0);
-	return clamp(wd * vec3(do_edge) + vec3(force_edge), 0.0, 1.0);
-}
+uniform float wireStepParam;
 
 float get_edge_sharpness(float wd)
 {
-	bool do_edge = (wd > 0.0);
-	bool force_edge = (wd == 1.0);
-	wd = (wireStepParam.x * wd + wireStepParam.y);
-	return clamp(wd * float(do_edge) + float(force_edge), 0.0, 1.0);
+	return (wd == 1.0) ? 1.0 : ((wd == 0.0) ? -1.0 : (wd + wireStepParam));
 }
 
 /* Geometry shader version */
@@ -51,35 +40,19 @@ void main()
 
 #else /* SELECT_EDGES */
 
-/* Consecutive pos of the nth vertex
- * Only valid for first vertex in the triangle.
- * Assuming GL_FRIST_VERTEX_CONVENTION. */
-in vec3 pos0;
-in vec3 pos1;
-in vec3 pos2;
-in float wd0; /* wiredata */
-in float wd1;
-in float wd2;
+in vec3 pos;
 in vec3 nor;
+in float wd;
 
 out float facing;
-out vec3 barycentric;
-flat out vec3 edgeSharpness;
+flat out float edgeSharpness;
 
 void main()
 {
-	int v_n = gl_VertexID % 3;
-
-	barycentric = vec3(equal(ivec3(2, 0, 1), ivec3(v_n)));
-
-	vec3 wb = vec3(wd0, wd1, wd2);
-	edgeSharpness = get_edge_sharpness(wb);
-
-	/* Don't generate any fragment if there is no edge to draw. */
-	vec3 pos = (!any(greaterThan(edgeSharpness, vec3(0.04))) && (v_n == 0)) ? pos1 : pos0;
-
 	gl_Position = ModelViewProjectionMatrix * vec4(pos, 1.0);
 
+	edgeSharpness = get_edge_sharpness(wd);
+
 	facing = normalize(NormalMatrix * nor).z;
 
 #ifdef USE_WORLD_CLIP_PLANES