Add draw_indirect & dispatch_indirect

Author: floppyhammer

pathfinder/gpu/command_encoder.cpp

@@ -105,6 +105,17 @@ void CommandEncoder::draw_instanced(uint32_t vertex_count, uint32_t instance_cou
     commands_.push_back(cmd);
 }
 
+void CommandEncoder::draw_indirect(Buffer *buffer, uint32_t offset) {
+    Command cmd;
+    cmd.type = CommandType::DrawIndirect;
+
+    auto &args = cmd.args.indirect;
+    args.buffer = buffer;
+    args.offset = offset;
+
+    commands_.push_back(cmd);
+}
+
 void CommandEncoder::end_render_pass() {
     Command cmd{};
     cmd.type = CommandType::EndRenderPass;
@@ -136,6 +147,17 @@ void CommandEncoder::dispatch(uint32_t group_size_x, uint32_t group_size_y, uint
     commands_.push_back(cmd);
 }
 
+void CommandEncoder::dispatch_indirect(Buffer *buffer, uint32_t offset) {
+    Command cmd;
+    cmd.type = CommandType::DispatchIndirect;
+
+    auto &args = cmd.args.indirect;
+    args.buffer = buffer;
+    args.offset = offset;
+
+    commands_.push_back(cmd);
+}
+
 void CommandEncoder::end_compute_pass() {
     Command cmd{};
     cmd.type = CommandType::EndComputePass;

pathfinder/gpu/command_encoder.h

@@ -29,13 +29,15 @@ enum class CommandType {
     BindDescriptorSet,
     Draw,
     DrawInstanced,
+    DrawIndirect,
     EndRenderPass,
 
     // COMPUTE PASS
 
     BeginComputePass,
     BindComputePipeline,
     Dispatch,
+    DispatchIndirect,
     EndComputePass,
 
     // DATA TRANSFER
@@ -82,6 +84,10 @@ struct Command {
             uint32_t vertex_count;
             uint32_t instance_count;
         } draw_instanced;
+        struct {
+            Buffer *buffer;
+            size_t offset;
+        } indirect;
         struct {
             ComputePipeline *pipeline;
         } bind_compute_pipeline;
@@ -155,6 +161,8 @@ class CommandEncoder {
 
     void draw_instanced(uint32_t vertex_count, uint32_t instance_count);
 
+    void draw_indirect(Buffer *buffer, uint32_t offset);
+
     void end_render_pass();
 
     // COMPUTE PASS
@@ -165,6 +173,8 @@ class CommandEncoder {
 
     void dispatch(uint32_t group_size_x, uint32_t group_size_y, uint32_t group_size_z);
 
+    void dispatch_indirect(Buffer *buffer, uint32_t offset);
+
     void end_compute_pass();
 
     // DATA TRANSFER

pathfinder/gpu/gl/command_encoder.cpp

@@ -225,6 +225,27 @@ bool CommandEncoderGl::finish() {
 
                 gl_check_error("DrawInstanced");
             } break;
+#ifdef PATHFINDER_ENABLE_COMPUTE
+            case CommandType::DrawIndirect: {
+                auto &args = cmd.args.indirect;
+                auto buffer_gl = (BufferGl *)args.buffer;
+
+                glBindBuffer(GL_DRAW_INDIRECT_BUFFER, buffer_gl->get_handle());
+                glDrawArraysIndirect(GL_TRIANGLES, reinterpret_cast<void *>(args.offset));
+
+                gl_check_error("DrawIndirect");
+            } break;
+            case CommandType::DispatchIndirect: {
+                auto &args = cmd.args.indirect;
+                auto buffer_gl = (BufferGl *)args.buffer;
+
+                glBindBuffer(GL_DISPATCH_INDIRECT_BUFFER, buffer_gl->get_handle());
+                glDispatchComputeIndirect(static_cast<GLintptr>(args.offset));
+                glMemoryBarrier(GL_SHADER_STORAGE_BARRIER_BIT);
+
+                gl_check_error("DispatchIndirect");
+            } break;
+#endif
             case CommandType::EndRenderPass: {
                 render_pipeline_ = nullptr;
             } break;

pathfinder/gpu/vk/command_encoder.cpp

@@ -321,6 +321,11 @@ bool CommandEncoderVk::finish() {
                 auto &args = cmd.args.draw_instanced;
                 vkCmdDraw(vk_command_buffer_, args.vertex_count, args.instance_count, 0, 0);
             } break;
+            case CommandType::DrawIndirect: {
+                auto &args = cmd.args.indirect;
+                auto buffer_vk = static_cast<BufferVk *>(args.buffer);
+                vkCmdDrawIndirect(vk_command_buffer_, buffer_vk->get_vk_buffer(), args.offset, 1, 0);
+            } break;
             case CommandType::EndRenderPass: {
                 vkCmdEndRenderPass(vk_command_buffer_);
 
@@ -353,6 +358,11 @@ bool CommandEncoderVk::finish() {
                 // Dispatch compute job.
                 vkCmdDispatch(vk_command_buffer_, args.group_size_x, args.group_size_y, args.group_size_z);
             } break;
+            case CommandType::DispatchIndirect: {
+                auto &args = cmd.args.indirect;
+                auto buffer_vk = static_cast<BufferVk *>(args.buffer);
+                vkCmdDispatchIndirect(vk_command_buffer_, buffer_vk->get_vk_buffer(), args.offset);
+            } break;
             case CommandType::EndComputePass: {
                 compute_pipeline_ = nullptr;
             } break;