1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
package main
import "core:fmt"
import bk "../../backend"
import compiler "../../compiler"
import gpu "../.."
import app "../../app"
import ir "../../render_ir"
import shaderkit "../../shaderkit"
Vertex :: struct {
position: [2]f32,
uv: [2]f32,
}
VERTEX_SHADER :: `
vertex main
in position: vec2 @location(0)
in uv: vec2 @location(1)
out position: vec4 @builtin(position)
out uv: vec2
do
position = vec4(position, 0.0, 1.0)
out.uv = uv
end
`
OFFSCREEN_FRAGMENT_SHADER :: `
fragment main
in uv: vec2
out color: vec4
do
let band = step(0.5, fract((uv.x + uv.y) * 8.0))
color = mix(vec4(0.05, 0.15, 0.65, 1.0), vec4(uv.x, uv.y, 0.25, 1.0), band)
end
`
SAMPLE_FRAGMENT_SHADER :: `
group frame = 0
@binding(0) texture offscreen_color: sampler2D
end
fragment main
in uv: vec2
out color: vec4
do
color = sample(offscreen_color, uv)
end
`
compile_shader :: proc(source, name: string, stage: bk.Shader_Stage) -> (bk.Shader_Handle, bool) {
return shaderkit.create_shader_from_source(name, stage, source, {opt_level = .Basic})
}
make_offscreen_ir :: proc() -> (frame: ir.Frame_IR, pass: ir.Pass_Handle, color: ir.Resource_Handle, sampler: ir.Resource_Handle) {
frame = ir.init_frame_ir()
color = ir.add_texture(&frame, "offscreen-color", 256, 256, .R8G8B8A8_UNORM, {.Color_Attachment, .Sampled}, .Transient)
depth := ir.add_texture(&frame, "offscreen-depth", 256, 256, .D32_SFLOAT, {.Depth_Stencil_Attachment}, .Transient)
sampler = ir.add_sampler(&frame, "offscreen-sampler", {
mag_filter = .Nearest,
min_filter = .Nearest,
address_mode_u = .Clamp_To_Edge,
address_mode_v = .Clamp_To_Edge,
mipmap_mode = .Nearest,
}, .Transient)
desc := ir.Pass_Desc{kind = .Render, name = "offscreen"}
_ = ir.pass_add_color_target(&desc, ir.make_color_target(color, .R8G8B8A8_UNORM, .Clear, .Store, {0, 0, 0, 1}))
ir.pass_set_depth_target(&desc, ir.make_depth_target(depth, .D32_SFLOAT, .Clear, .Dont_Care, 1))
ir.pass_set_viewport(&desc, {x = 0, y = 0, width = 256, height = 256, min_depth = 0, max_depth = 1})
ir.pass_set_scissor(&desc, {x = 0, y = 0, width = 256, height = 256})
pass = ir.add_pass(&frame, desc)
return
}
create_quad_buffers :: proc(backend: ^bk.Backend) -> (bk.Buffer_Handle, bk.Buffer_Handle, bool) {
vertices := [?]Vertex{
{position = {-0.85, -0.85}, uv = {0, 1}},
{position = { 0.85, -0.85}, uv = {1, 1}},
{position = { 0.85, 0.85}, uv = {1, 0}},
{position = {-0.85, 0.85}, uv = {0, 0}},
}
indices := [?]u32{0, 1, 2, 2, 3, 0}
vb, vb_ok := backend.create_buffer_staged(raw_data(vertices[:]), len(vertices) * size_of(Vertex), {.Vertex})
if !vb_ok {
return {}, {}, false
}
ib, ib_ok := backend.create_buffer_staged(raw_data(indices[:]), len(indices) * size_of(u32), {.Index})
if !ib_ok {
backend.destroy_buffer(vb)
return {}, {}, false
}
return vb, ib, true
}
create_pipeline :: proc(
vs, fs: bk.Shader_Handle,
render_pass: bk.Render_Pass_Handle,
descriptor_layouts: []bk.Descriptor_Handle = nil,
) -> (bk.Pipeline_Handle, bool) {
bindings := [1]bk.Vertex_Binding{{binding = 0, stride = size_of(Vertex)}}
attrs := [2]bk.Vertex_Attribute{
{location = 0, offset = 0, format = .Float2},
{location = 1, offset = 8, format = .Float2},
}
return gpu.create_pipeline({
vert_shader = vs,
frag_shader = fs,
render_pass = render_pass,
topology = .Triangle_List,
cull_mode = .None,
front_face = .Counter_Clockwise,
enable_blending = false,
blend_mode = .Alpha,
enable_depth_test = false,
depth_only = false,
descriptor_layouts = descriptor_layouts,
vertex_bindings = bindings[:],
vertex_attributes = attrs[:],
})
}
main :: proc() {
when gpu.REQUIRED_SHADER_FORMAT != .SPIRV {
fmt.println("offscreen_ir: Vulkan runtime proof only; D3D executor parity is tracked separately")
return
}
state, ok := app.init_window(800, 600, "GPU - Offscreen IR")
if !ok {
return
}
defer app.shutdown(&state)
backend := gpu.get_backend()
if backend == nil {
return
}
frame, offscreen_pass, color_resource, sampler_resource := make_offscreen_ir()
defer ir.destroy_frame_ir(&frame)
exec := compiler.init_execution_state(backend)
defer compiler.destroy_execution_state(&exec)
if !compiler.prepare_render_targets(&exec, &frame) {
return
}
offscreen_render_pass, rp_ok := compiler.prepared_render_pass(&exec, offscreen_pass)
if !rp_ok {
return
}
offscreen_texture, tex_ok := compiler.prepared_texture(&exec, color_resource)
offscreen_sampler, sampler_ok := compiler.prepared_sampler(&exec, sampler_resource)
if !tex_ok || !sampler_ok {
return
}
vs, vs_ok := compile_shader(VERTEX_SHADER, "offscreen_ir.vert", .Vertex)
if !vs_ok { return }
defer gpu.destroy_shader(vs)
fs_offscreen, fs_offscreen_ok := compile_shader(OFFSCREEN_FRAGMENT_SHADER, "offscreen_ir_offscreen.frag", .Fragment)
if !fs_offscreen_ok { return }
defer gpu.destroy_shader(fs_offscreen)
fs_sample, fs_sample_ok := compile_shader(SAMPLE_FRAGMENT_SHADER, "offscreen_ir_sample.frag", .Fragment)
if !fs_sample_ok { return }
defer gpu.destroy_shader(fs_sample)
offscreen_pipeline, offscreen_pipeline_ok := create_pipeline(vs, fs_offscreen, offscreen_render_pass)
if !offscreen_pipeline_ok { return }
defer gpu.destroy_pipeline(offscreen_pipeline)
descriptor_layout, descriptor_layout_ok := backend.create_descriptor_set_layout({{
binding = 0,
type = .Combined_Image_Sampler,
count = 1,
stages = {.Fragment},
}})
if !descriptor_layout_ok { return }
defer backend.destroy_descriptor_set_layout(descriptor_layout)
descriptor_types := [1]bk.Descriptor_Type{.Combined_Image_Sampler}
descriptor_counts := [1]u32{1}
descriptor_pool, descriptor_pool_ok := backend.create_descriptor_pool(1, descriptor_types[:], descriptor_counts[:])
if !descriptor_pool_ok { return }
defer backend.destroy_descriptor_pool(descriptor_pool)
descriptor_set, descriptor_set_ok := backend.allocate_descriptor_set(descriptor_pool, descriptor_layout)
if !descriptor_set_ok { return }
backend.update_descriptor_image(descriptor_set, 0, offscreen_texture, offscreen_sampler, .Shader_Read_Only)
descriptor_layouts := [1]bk.Descriptor_Handle{descriptor_layout}
sample_pipeline, sample_pipeline_ok := create_pipeline(vs, fs_sample, gpu.get_default_render_pass(), descriptor_layouts[:])
if !sample_pipeline_ok { return }
defer gpu.destroy_pipeline(sample_pipeline)
vertex_buffer, index_buffer, buffers_ok := create_quad_buffers(backend)
if !buffers_ok { return }
defer backend.destroy_buffer(index_buffer)
defer backend.destroy_buffer(vertex_buffer)
wrote_offscreen := false
for !app.window_should_close(&state) {
app.begin_drawing(&state, gpu.BLACK)
ctx := gpu.get_frame_context()
if !wrote_offscreen {
if compiler.begin_prepared_pass(&exec, ctx, offscreen_pass) {
backend.bind_graphics_pipeline(ctx, offscreen_pipeline)
backend.bind_vertex_buffer(ctx, vertex_buffer)
backend.bind_index_buffer(ctx, index_buffer)
backend.draw_indexed(ctx, 6, 1, 0, 0, 0)
compiler.end_prepared_pass(&exec, ctx)
wrote_offscreen = true
}
}
if gpu.ensure_default_render_pass() {
backend.bind_graphics_pipeline(ctx, sample_pipeline)
backend.bind_descriptor_set(ctx, sample_pipeline, descriptor_set, 0)
backend.bind_vertex_buffer(ctx, vertex_buffer)
backend.bind_index_buffer(ctx, index_buffer)
backend.draw_indexed(ctx, 6, 1, 0, 0, 0)
}
app.end_drawing(&state)
if app.is_key_pressed(&state, .Escape) {
break
}
}
}