v3dv: enable smooth line rendering

This is based on a lowering that we are already using in the OpenGL
driver.

Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Signed-off-by: Juan A. Suarez Romero <jasuarez@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/28171>

src/broadcom/vulkan/v3dv_cmd_buffer.c

@@ -27,6 +27,21 @@
 #include "vk_common_entrypoints.h"
 #include "vk_util.h"
 
+float
+v3dv_get_aa_line_width(struct v3dv_pipeline *pipeline,
+                       struct v3dv_cmd_buffer *buffer)
+{
+   float width = buffer->state.dynamic.line_width;
+
+   /* If line smoothing is enabled then we want to add some extra pixels to
+    * the width in order to have some semi-transparent edges.
+    */
+   if (pipeline->line_smooth)
+      width = floorf(M_SQRT2 * width) + 3;
+
+   return width;
+}
+
 void
 v3dv_job_add_bo(struct v3dv_job *job, struct v3dv_bo *bo)
 {

src/broadcom/vulkan/v3dv_device.c

@@ -394,7 +394,7 @@ get_features(const struct v3dv_physical_device *physical_device,
       /* VK_EXT_line_rasterization */
       .rectangularLines = true,
       .bresenhamLines = true,
-      .smoothLines = false,
+      .smoothLines = true,
       .stippledRectangularLines = false,
       .stippledBresenhamLines = false,
       .stippledSmoothLines = false,

src/broadcom/vulkan/v3dv_pipeline.c

@@ -1095,6 +1095,32 @@ static const enum pipe_logicop vk_to_pipe_logicop[] = {
    [VK_LOGIC_OP_SET] = PIPE_LOGICOP_SET,
 };
 
+static bool
+enable_line_smooth(uint8_t topology,
+                   const VkPipelineRasterizationStateCreateInfo *rs_info)
+{
+   if (!rs_info || rs_info->rasterizerDiscardEnable)
+      return false;
+
+   const VkPipelineRasterizationLineStateCreateInfoKHR *ls_info =
+      vk_find_struct_const(rs_info->pNext,
+                           PIPELINE_RASTERIZATION_LINE_STATE_CREATE_INFO_KHR);
+
+   if (!ls_info)
+      return false;
+
+   switch(topology) {
+   case MESA_PRIM_LINES:
+   case MESA_PRIM_LINE_LOOP:
+   case MESA_PRIM_LINE_STRIP:
+   case MESA_PRIM_LINES_ADJACENCY:
+   case MESA_PRIM_LINE_STRIP_ADJACENCY:
+      return ls_info->lineRasterizationMode == VK_LINE_RASTERIZATION_MODE_RECTANGULAR_SMOOTH_KHR;
+   default:
+      return false;
+   }
+}
+
 static void
 pipeline_populate_v3d_fs_key(struct v3d_fs_key *key,
                              const VkGraphicsPipelineCreateInfo *pCreateInfo,
@@ -1159,6 +1185,8 @@ pipeline_populate_v3d_fs_key(struct v3d_fs_key *key,
       key->sample_alpha_to_one = ms_info->alphaToOneEnable;
    }
 
+   key->line_smoothing = enable_line_smooth(topology, pCreateInfo->pRasterizationState);
+
    /* This is intended for V3D versions before 4.1, otherwise we just use the
     * tile buffer load/store swap R/B bit.
     */
@@ -1950,6 +1978,8 @@ pipeline_populate_graphics_key(struct v3dv_pipeline *pipeline,
 
    memset(key, 0, sizeof(*key));
 
+   key->line_smooth = pipeline->line_smooth;
+
    const bool raster_enabled =
       pCreateInfo->pRasterizationState &&
       !pCreateInfo->pRasterizationState->rasterizerDiscardEnable;
@@ -2950,6 +2980,7 @@ pipeline_init(struct v3dv_pipeline *pipeline,
 
    pipeline_set_sample_mask(pipeline, ms_info);
    pipeline_set_sample_rate_shading(pipeline, ms_info);
+   pipeline->line_smooth = enable_line_smooth(pipeline->topology, rs_info);
 
    pipeline->primitive_restart =
       pCreateInfo->pInputAssemblyState->primitiveRestartEnable;

src/broadcom/vulkan/v3dv_private.h

@@ -339,6 +339,7 @@ struct v3dv_pipeline_key {
    uint8_t f32_color_rb;
    uint32_t va_swap_rb_mask;
    bool has_multiview;
+   bool line_smooth;
 };
 
 struct v3dv_pipeline_cache_stats {
@@ -2297,6 +2298,8 @@ struct v3dv_pipeline {
 
    enum mesa_prim topology;
 
+   bool line_smooth;
+
    struct v3dv_pipeline_shared_data *shared_data;
 
    /* It is the combined stages sha1, layout sha1, plus the pipeline key sha1. */
@@ -2680,6 +2683,10 @@ v3dv_update_image_layout(struct v3dv_device *device,
                          bool disjoint,
                          const VkImageDrmFormatModifierExplicitCreateInfoEXT *explicit_mod_info);
 
+float
+v3dv_get_aa_line_width(struct v3dv_pipeline *pipeline,
+                       struct v3dv_cmd_buffer *buffer);
+
 #if DETECT_OS_ANDROID
 VkResult
 v3dv_gralloc_to_drm_explicit_layout(struct u_gralloc *gralloc,

src/broadcom/vulkan/v3dv_uniforms.c

@@ -661,6 +661,15 @@ v3dv_write_uniforms_wg_offsets(struct v3dv_cmd_buffer *cmd_buffer,
          cl_aligned_u32(&uniforms, job->cmd_buffer->state.draw_id);
          break;
 
+      case QUNIFORM_LINE_WIDTH:
+         cl_aligned_u32(&uniforms, job->cmd_buffer->state.dynamic.line_width);
+         break;
+
+      case QUNIFORM_AA_LINE_WIDTH:
+         cl_aligned_u32(&uniforms,
+                        v3dv_get_aa_line_width(pipeline, job->cmd_buffer));
+         break;
+
       default:
          unreachable("unsupported quniform_contents uniform type\n");
       }

src/broadcom/vulkan/v3dvx_cmd_buffer.c

@@ -1551,7 +1551,8 @@ v3dX(cmd_buffer_emit_line_width)(struct v3dv_cmd_buffer *cmd_buffer)
    v3dv_return_if_oom(cmd_buffer, NULL);
 
    cl_emit(&job->bcl, LINE_WIDTH, line) {
-      line.line_width = cmd_buffer->state.dynamic.line_width;
+      line.line_width = v3dv_get_aa_line_width(cmd_buffer->state.gfx.pipeline,
+                                               cmd_buffer);
    }
 
    cmd_buffer->state.dirty &= ~V3DV_CMD_DIRTY_LINE_WIDTH;