#!amber
# Copyright 2020 The Amber Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Demonstrate reads and writes on row major and column major matrices.

SHADER compute copy_vertex GLSL
#version 450

layout(set=0, binding=0) buffer A {
   layout(column_major) mat2x4 mcols;
   layout(row_major) mat2x4 mrows;
} inbound;

layout(set=0, binding=1) buffer B {
   vec4 first;
   vec4 second;
} outbound;

void main() {
  outbound.first = inbound.mcols[1];
  outbound.second = inbound.mrows[1];  // Read is a gather
  inbound.mcols[0] = inbound.mrows[0];
  inbound.mrows[1] = inbound.mcols[1]; // Write is a scatter
}
END

BUFFER buf0 DATA_TYPE float DATA

 # Column major mcols.

   # first column
   00.0 01.0 02.0 03.0
   # second column
   10.0 11.0 12.0 13.0

 # Row major
   # first row
   100.0 110.0
   # second row
   101.0 111.0
   # third row
   102.0 112.0
   # fourth row
   103.0 113.0
END

BUFFER buf1 DATA_TYPE float DATA
   # Initialize with garbage data.
   -1.0 -1.0 -1.0 -1.0
   -2.0 -2.0 -2.0 -2.0
END

PIPELINE compute pipeline
  ATTACH copy_vertex
  BIND BUFFER buf0 AS storage DESCRIPTOR_SET 0 BINDING 0
  BIND BUFFER buf1 AS storage DESCRIPTOR_SET 0 BINDING 1
END

RUN pipeline 1 1 1

# Check the column vectors we copied out.
# From inbound.mcols[1]
EXPECT buf1 IDX 0  EQ 10.0 11.0 12. 13.0
# From inbound.mrows[1]
# Did a gather from mrows[1] to collect these values before writing them out.
EXPECT buf1 IDX 16 EQ 110.0 111.0 112. 113.0

# Check the contents of inbound.mcols
EXPECT buf0 IDX 0 EQ 100.0 101.0 102.0 103.0  # Did a gather from mrows[0]
EXPECT buf0 IDX 16 EQ 10.0 11.0 12.0 13.0     # Second column is unchanged
# Check the conents of inbound.mrows
# Writing to second column of row major is a scatter operation
EXPECT buf0 IDX 32 EQ 100.0 10.0
EXPECT buf0 IDX 40 EQ 101.0 11.0
EXPECT buf0 IDX 48 EQ 102.0 12.0
EXPECT buf0 IDX 56 EQ 103.0 13.0