Files
codegirl-games/engine/fps_overlay.odin
T

280 lines
7.1 KiB
Odin

package engine
import "core:fmt"
import "core:mem"
import sdl "vendor:sdl3"
// Enough for an 8-digit rate plus " FPS".
FPS_OVERLAY_MAX_GLYPHS :: 12
FPS_GLYPH_W :: 5
FPS_GLYPH_H :: 7
FPS_CELL_W :: 6
FPS_CELL_H :: 8
FPS_ATLAS_COLS :: 16
FPS_SCALE :: 2
FPS_MARGIN :: 8
FPS_UPDATE_INTERVAL :: 0.25
// Glyph indices in the debug atlas.
FPS_GLYPH_DIGIT_0 :: 0
FPS_GLYPH_F :: 10
FPS_GLYPH_P :: 11
FPS_GLYPH_S :: 12
FPS_GLYPH_SPACE :: 13
// 5x7 bitmaps (MSB = left). Digits 0-9, then F/P/S/space.
@(private)
fps_glyph_rows := [14][7]u8 {
{0x0E, 0x11, 0x13, 0x15, 0x19, 0x11, 0x0E}, // 0
{0x04, 0x0C, 0x04, 0x04, 0x04, 0x04, 0x0E}, // 1
{0x0E, 0x11, 0x01, 0x06, 0x08, 0x10, 0x1F}, // 2
{0x0E, 0x11, 0x01, 0x06, 0x01, 0x11, 0x0E}, // 3
{0x02, 0x06, 0x0A, 0x12, 0x1F, 0x02, 0x02}, // 4
{0x1F, 0x10, 0x1E, 0x01, 0x01, 0x11, 0x0E}, // 5
{0x06, 0x08, 0x10, 0x1E, 0x11, 0x11, 0x0E}, // 6
{0x1F, 0x01, 0x02, 0x04, 0x08, 0x08, 0x08}, // 7
{0x0E, 0x11, 0x11, 0x0E, 0x11, 0x11, 0x0E}, // 8
{0x0E, 0x11, 0x11, 0x0F, 0x01, 0x02, 0x0C}, // 9
{0x1F, 0x10, 0x10, 0x1E, 0x10, 0x10, 0x10}, // F
{0x1E, 0x11, 0x11, 0x1E, 0x10, 0x10, 0x10}, // P
{0x0F, 0x10, 0x10, 0x0E, 0x01, 0x01, 0x1E}, // S
{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}, // space
}
set_show_fps :: proc(app: ^App, enabled: bool) {
if app == nil do return
app.show_fps = enabled
}
@(private)
fps_overlay_init :: proc(app: ^App) -> bool {
app.show_fps = true
app.fps_smooth = 0
app.fps_display = 0
app.fps_last_time = 0
app.fps_update_accum = 0
app.fps_texture = nil
atlas_w := FPS_ATLAS_COLS * FPS_CELL_W
atlas_h := FPS_CELL_H
pixels := make([]u8, atlas_w * atlas_h * 4)
defer delete(pixels)
for gi in 0 ..< len(fps_glyph_rows) {
gx := gi * FPS_CELL_W
rows := fps_glyph_rows[gi]
for row in 0 ..< FPS_GLYPH_H {
bits := rows[row]
for col in 0 ..< FPS_GLYPH_W {
on := (bits >> u8(FPS_GLYPH_W - 1 - col)) & 1 == 1
px := gx + col
py := row
i := (py * atlas_w + px) * 4
if on {
pixels[i + 0] = 255
pixels[i + 1] = 255
pixels[i + 2] = 255
pixels[i + 3] = 255
}
}
}
}
app.fps_texture = sdl.CreateGPUTexture(
app.device,
{
type = .D2,
format = .R8G8B8A8_UNORM,
usage = {.SAMPLER},
width = u32(atlas_w),
height = u32(atlas_h),
layer_count_or_depth = 1,
num_levels = 1,
sample_count = ._1,
},
)
if app.fps_texture == nil {
fmt.eprintfln("FPS overlay CreateGPUTexture failed: %s", sdl.GetError())
return false
}
upload_size := atlas_w * atlas_h * 4
tbuf := sdl.CreateGPUTransferBuffer(app.device, {usage = .UPLOAD, size = u32(upload_size)})
if tbuf == nil {
fmt.eprintfln("FPS overlay CreateGPUTransferBuffer failed: %s", sdl.GetError())
sdl.ReleaseGPUTexture(app.device, app.fps_texture)
app.fps_texture = nil
return false
}
defer sdl.ReleaseGPUTransferBuffer(app.device, tbuf)
map_ptr := sdl.MapGPUTransferBuffer(app.device, tbuf, false)
if map_ptr == nil {
fmt.eprintfln("FPS overlay MapGPUTransferBuffer failed: %s", sdl.GetError())
sdl.ReleaseGPUTexture(app.device, app.fps_texture)
app.fps_texture = nil
return false
}
mem.copy(map_ptr, raw_data(pixels), upload_size)
sdl.UnmapGPUTransferBuffer(app.device, tbuf)
cmd := sdl.AcquireGPUCommandBuffer(app.device)
if cmd == nil {
fmt.eprintfln("FPS overlay AcquireGPUCommandBuffer failed: %s", sdl.GetError())
sdl.ReleaseGPUTexture(app.device, app.fps_texture)
app.fps_texture = nil
return false
}
copy_pass := sdl.BeginGPUCopyPass(cmd)
transfer := sdl.GPUTextureTransferInfo {
transfer_buffer = tbuf,
offset = 0,
pixels_per_row = u32(atlas_w),
rows_per_layer = u32(atlas_h),
}
region := sdl.GPUTextureRegion {
texture = app.fps_texture,
w = u32(atlas_w),
h = u32(atlas_h),
d = 1,
}
sdl.UploadToGPUTexture(copy_pass, transfer, region, false)
sdl.EndGPUCopyPass(copy_pass)
fence := sdl.SubmitGPUCommandBufferAndAcquireFence(cmd)
if fence == nil {
fmt.eprintfln("FPS overlay texture upload submit failed: %s", sdl.GetError())
sdl.ReleaseGPUTexture(app.device, app.fps_texture)
app.fps_texture = nil
return false
}
defer sdl.ReleaseGPUFence(app.device, fence)
if !sdl.WaitForGPUFences(app.device, true, &fence, 1) {
fmt.eprintfln("FPS overlay WaitForGPUFences failed: %s", sdl.GetError())
sdl.ReleaseGPUTexture(app.device, app.fps_texture)
app.fps_texture = nil
return false
}
return true
}
@(private)
fps_overlay_shutdown :: proc(app: ^App) {
if app.device != nil && app.fps_texture != nil {
sdl.ReleaseGPUTexture(app.device, app.fps_texture)
}
app.fps_texture = nil
}
@(private)
fps_overlay_begin_frame :: proc(app: ^App) {
now := now_seconds()
if app.fps_last_time > 0 {
dt := now - app.fps_last_time
if dt > 0 {
instant := f32(1.0 / dt)
if app.fps_smooth <= 0 {
app.fps_smooth = instant
} else {
app.fps_smooth = app.fps_smooth * 0.9 + instant * 0.1
}
app.fps_update_accum += f32(dt)
if app.fps_display == 0 || app.fps_update_accum >= FPS_UPDATE_INTERVAL {
app.fps_display = int(app.fps_smooth + 0.5)
app.fps_update_accum = 0
}
}
}
app.fps_last_time = now
}
@(private)
fps_overlay_queue :: proc(app: ^App) {
if !app.show_fps || app.fps_texture == nil do return
if app.cmd == nil || app.swapchain_texture == nil do return
if app.swapchain_w == 0 || app.swapchain_h == 0 do return
fps := app.fps_display
if fps < 0 do fps = 0
// Build "N… FPS" with the full measured rate (no artificial cap).
glyphs: [FPS_OVERLAY_MAX_GLYPHS]int
count := 0
digits: [8]int
dcount := 0
if fps == 0 {
digits[0] = 0
dcount = 1
} else {
v := fps
for v > 0 && dcount < len(digits) {
digits[dcount] = v % 10
dcount += 1
v /= 10
}
for i in 0 ..< dcount / 2 {
digits[i], digits[dcount - 1 - i] = digits[dcount - 1 - i], digits[i]
}
}
for i in 0 ..< dcount {
if count >= FPS_OVERLAY_MAX_GLYPHS do break
glyphs[count] = FPS_GLYPH_DIGIT_0 + digits[i]
count += 1
}
if count + 4 <= FPS_OVERLAY_MAX_GLYPHS {
glyphs[count] = FPS_GLYPH_SPACE
count += 1
glyphs[count] = FPS_GLYPH_F
count += 1
glyphs[count] = FPS_GLYPH_P
count += 1
glyphs[count] = FPS_GLYPH_S
count += 1
}
sw := f32(app.swapchain_w)
sh := f32(app.swapchain_h)
atlas_w := f32(FPS_ATLAS_COLS * FPS_CELL_W)
atlas_h := f32(FPS_CELL_H)
gw := f32(FPS_GLYPH_W * FPS_SCALE)
gh := f32(FPS_GLYPH_H * FPS_SCALE)
advance := f32(FPS_CELL_W * FPS_SCALE)
x := f32(FPS_MARGIN)
y := f32(FPS_MARGIN)
for i in 0 ..< count {
if len(app.draw_list) >= MAX_SPRITES do break
gi := glyphs[i]
u0 := f32(gi * FPS_CELL_W) / atlas_w
v0 := f32(0)
u1 := f32(gi * FPS_CELL_W + FPS_GLYPH_W) / atlas_w
v1 := f32(FPS_GLYPH_H) / atlas_h
x0 := x + f32(i) * advance
y0 := y
x1 := x0 + gw
y1 := y0 + gh
p0 := to_clip(x0, y0, sw, sh)
p1 := to_clip(x1, y0, sw, sh)
p2 := to_clip(x1, y1, sw, sh)
p3 := to_clip(x0, y1, sw, sh)
verts := [SPRITE_VERT_COUNT]Vertex {
{pos = p0, uv = {u0, v0}},
{pos = p1, uv = {u1, v0}},
{pos = p2, uv = {u1, v1}},
{pos = p0, uv = {u0, v0}},
{pos = p2, uv = {u1, v1}},
{pos = p3, uv = {u0, v1}},
}
append(&app.draw_list, Queued_Sprite{texture = app.fps_texture, verts = verts})
}
}