#!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.

SHADER vertex vert_shader PASSTHROUGH

SHADER fragment frag_shader_red GLSL
#version 430
layout(location = 0) out vec4 color_out;
void main() {
  color_out = vec4(1.0, 0.0, 0.0, 1.0);
}
END

SHADER vertex vert_shader_tex GLSL
#version 430
layout(location = 0) in vec4 position;
layout(location = 1) in vec2 texcoords_in;
layout(location = 0) out vec2 texcoords_out;
void main() {
  gl_Position = position;
  texcoords_out = texcoords_in;
}
END

SHADER fragment frag_shader_tex GLSL
#version 430
layout(location = 0) in vec2 texcoords_in;
layout(location = 0) out vec4 color_out;
uniform layout(set=0, binding=0) sampler2D tex_sampler_white;
uniform layout(set=0, binding=1) sampler2D tex_sampler_black;
void main() {
  // Use a sampler with a white border color for the right
  // side of the color buffer and a sampler with a black
  // border color for the left side.
  if (gl_FragCoord.x > 128.0)
      color_out = texture(tex_sampler_white, texcoords_in);
  else
      color_out = texture(tex_sampler_black, texcoords_in);
}
END

BUFFER texture FORMAT R8G8B8A8_UNORM
BUFFER framebuffer FORMAT B8G8R8A8_UNORM

# A sampler that generates white when texture coordinates
# go out of range [0..1].
SAMPLER sampler_white \
  ADDRESS_MODE_U clamp_to_border \
  ADDRESS_MODE_V clamp_to_border \
  BORDER_COLOR float_opaque_white

# A sampler that generates black when texture coordinates
# go out of range [0..1].
SAMPLER sampler_black \
  ADDRESS_MODE_U clamp_to_border \
  ADDRESS_MODE_V clamp_to_border \
  BORDER_COLOR float_opaque_black

BUFFER position DATA_TYPE vec2<float> DATA
-0.75 -0.75
 0.75 -0.75
 0.75  0.75
-0.75  0.75
END
BUFFER texcoords DATA_TYPE vec2<float> DATA
-0.5 -0.5
 1.5 -0.5
 1.5  1.5
-0.5  1.5
END

# A pipeline for generating a texture. Renders pure red.
PIPELINE graphics texgen
  ATTACH vert_shader
  ATTACH frag_shader_red
  FRAMEBUFFER_SIZE 256 256
  BIND BUFFER texture AS color LOCATION 0
END

# A pipeline for drawing a textured quad using two samplers.
PIPELINE graphics pipeline
  ATTACH vert_shader_tex
  ATTACH frag_shader_tex
  BIND BUFFER texture AS combined_image_sampler SAMPLER sampler_white DESCRIPTOR_SET 0 BINDING 0
  BIND BUFFER texture AS combined_image_sampler SAMPLER sampler_black DESCRIPTOR_SET 0 BINDING 1
  VERTEX_DATA position LOCATION 0
  VERTEX_DATA texcoords LOCATION 1
  FRAMEBUFFER_SIZE 256 256
  BIND BUFFER framebuffer AS color LOCATION 0
END

# Generate a texture with a blue background and red quad at the lower right corner.
CLEAR_COLOR texgen 0 0 255 255
CLEAR texgen
RUN texgen DRAW_RECT POS 128 128 SIZE 128 128

# Clear to green and draw the generated texture in the center of the screen leaving
# the background color to the edges. Use texture coordinates that go past the [0..1]
# range to show border colors. The left side of the texture is using a sampler with
# a black border, and the right side uses a sampler with a white border.
CLEAR_COLOR pipeline 0 255 0 255
CLEAR pipeline
RUN pipeline DRAW_ARRAY AS TRIANGLE_FAN START_IDX 0 COUNT 4

# Check for the green background.
EXPECT framebuffer IDX 1 1 SIZE 1 1 EQ_RGBA 0 255 0 255
# Check for the black border color.
EXPECT framebuffer IDX 55 55 SIZE 1 1 EQ_RGBA 0 0 0 255
# Check for the blue part of the texture.
EXPECT framebuffer IDX 105 105 SIZE 1 1 EQ_RGBA 0 0 255 255
# Check for the red part of the texture.
EXPECT framebuffer IDX 150 150 SIZE 1 1 EQ_RGBA 255 0 0 255
# Check for the white border color.
EXPECT framebuffer IDX 200 200 SIZE 1 1 EQ_RGBA 255 255 255 255