gg: support `VGG_STOP_AT_FRAME=120 VGG_SCREENSHOT_FOLDER=. VGG_SCREENSHOT_FRAMES=10,20,30 ./v -d gg_record run examples/gg/bezier_anim.v` (#12767)

cmd/tools/vtest-all.v

@@ -181,7 +181,7 @@ fn get_all_commands() []Command {
 	}
 	$if macos || linux {
 		res << Command{
-			line: '$vexe -o v.c cmd/v && cc -Werror -I "$vroot/thirdparty/stdatomic/nix" v.c -lpthread && rm -rf a.out'
+			line: '$vexe -o v.c cmd/v && cc -Werror -I "$vroot/thirdparty/stdatomic/nix" v.c -lpthread -lm && rm -rf a.out'
 			label: 'v.c should be buildable with no warnings...'
 			okmsg: 'v.c can be compiled without warnings. This is good :)'
 			rmfile: 'v.c'

vlib/gg/gg.v

@@ -106,6 +106,8 @@ fn gg_frame_fn(user_data voidptr) {
 		// return
 	}
 
+	ctx.record_frame()
+
 	if ctx.ui_mode && !ctx.needs_refresh {
 		// Draw 3 more frames after the "stop refresh" command
 		ctx.ticks++
@@ -250,8 +252,8 @@ fn gg_fail_fn(msg &char, user_data voidptr) {
 	}
 }
 
-pub fn (gg &Context) run() {
-	sapp.run(&gg.window)
+pub fn (ctx &Context) run() {
+	sapp.run(&ctx.window)
 }
 
 // quit closes the context window and exits the event loop for it

vlib/gg/recorder.v

@@ -0,0 +1,49 @@
+module gg
+
+import os
+import sokol.sapp
+
+[heap]
+pub struct SSRecorderSettings {
+pub mut:
+	stop_at_frame     i64 = -1
+	screenshot_frames []u64
+	screenshot_folder string
+	screenshot_prefix string
+}
+
+const recorder_settings = new_gg_recorder_settings()
+
+fn new_gg_recorder_settings() &SSRecorderSettings {
+	$if gg_record ? {
+		stop_frame := os.getenv_opt('VGG_STOP_AT_FRAME') or { '-1' }.i64()
+		frames := os.getenv('VGG_SCREENSHOT_FRAMES').split_any(',').map(it.u64())
+		folder := os.getenv('VGG_SCREENSHOT_FOLDER')
+		prefix := os.join_path_single(folder, os.file_name(os.executable()).all_before('.') + '_')
+		return &SSRecorderSettings{
+			stop_at_frame: stop_frame
+			screenshot_frames: frames
+			screenshot_folder: folder
+			screenshot_prefix: prefix
+		}
+	} $else {
+		return &SSRecorderSettings{}
+	}
+}
+
+[if gg_record ?]
+pub fn (mut ctx Context) record_frame() {
+	if ctx.frame in gg.recorder_settings.screenshot_frames {
+		screenshot_file_path := '$gg.recorder_settings.screenshot_prefix${ctx.frame}.png'
+		$if gg_record_trace ? {
+			eprintln('>>> screenshoting $screenshot_file_path')
+		}
+		sapp.screenshot_png(screenshot_file_path) or { panic(err) }
+	}
+	if ctx.frame == gg.recorder_settings.stop_at_frame {
+		$if gg_record_trace ? {
+			eprintln('>>> exiting at frame $ctx.frame')
+		}
+		exit(0)
+	}
+}

vlib/sokol/sapp/sapp_v.c.v

@@ -1,50 +1,54 @@
 module sapp
 
 import os
+import stbi
 
 // v_sapp_gl_read_rgba_pixels reads pixles from the OpenGL buffer into `pixels`.
 fn C.v_sapp_gl_read_rgba_pixels(x int, y int, width int, height int, pixels charptr)
 
 // screenshot takes a screenshot of the current window.
-[inline]
 pub fn screenshot(path string) ? {
 	if !path.ends_with('.ppm') {
 		return error(@MOD + '.' + @FN + ' currently only supports .ppm files.')
 	}
+	return screenshot_ppm(path)
+}
 
-	w := width()
-	h := height()
+// screenshot_ppm takes a screenshot of the current window as a .ppm file
+[manualfree]
+pub fn screenshot_ppm(path string) ? {
+	ss := screenshot_window()
+	write_rgba_to_ppm(path, ss.width, ss.height, 4, ss.pixels) ?
+	unsafe { ss.destroy() }
+}
 
-	size := w * h * 4 //
-	mut pixels := []byte{len: size, init: 0}
-
-	C.v_sapp_gl_read_rgba_pixels(0, 0, w, h, pixels.data)
-
-	// TODO use separate thread for writing the data
-	// TODO use stbi to support more formats
-	// stbi.write_png(path, w, h, components, pixels.data, 3 * w)
-	// stbi.write_tga(path, w, h, components, pixels.data)
-	write_rgba_to_ppm(path, w, h, 4, pixels) ?
-
-	unsafe {
-		pixels.free()
-	}
+// screenshot_png takes a screenshot of the current window as a .png file
+[manualfree]
+pub fn screenshot_png(path string) ? {
+	ss := screenshot_window()
+	stbi.set_flip_vertically_on_write(true)
+	stbi.stbi_write_png(path, ss.width, ss.height, 4, ss.pixels, ss.width * 4) ?
+	unsafe { ss.destroy() }
 }
 
 // write_rgba_to_ppm writes `pixels` data in RGBA format to PPM3 format.
-fn write_rgba_to_ppm(path string, w int, h int, components int, pixels []byte) ? {
+fn write_rgba_to_ppm(path string, w int, h int, components int, pixels &byte) ? {
 	mut f_out := os.create(path) ?
+	defer {
+		f_out.close()
+	}
 	f_out.writeln('P3') ?
 	f_out.writeln('$w $h') ?
 	f_out.writeln('255') ?
 	for i := h - 1; i >= 0; i-- {
 		for j := 0; j < w; j++ {
 			idx := i * w * components + j * components
-			r := int(pixels[idx])
-			g := int(pixels[idx + 1])
-			b := int(pixels[idx + 2])
-			f_out.write_string('$r $g $b ') ?
+			unsafe {
+				r := int(pixels[idx])
+				g := int(pixels[idx + 1])
+				b := int(pixels[idx + 2])
+				f_out.write_string('$r $g $b ') ?
+			}
 		}
 	}
-	f_out.close()
 }

vlib/sokol/sapp/screenshot.c.v

@@ -0,0 +1,42 @@
+module sapp
+
+[heap]
+pub struct Screenshot {
+	width  int
+	height int
+	size   int
+mut:
+	pixels &byte
+}
+
+[manualfree]
+pub fn screenshot_window() &Screenshot {
+	img_width := width()
+	img_height := height()
+	img_size := img_width * img_height * 4
+	img_pixels := unsafe { &byte(malloc(img_size)) }
+	C.v_sapp_gl_read_rgba_pixels(0, 0, img_width, img_height, img_pixels)
+	return &Screenshot{
+		width: img_width
+		height: img_height
+		size: img_size
+		pixels: img_pixels
+	}
+}
+
+// free - free *only* the Screenshot pixels.
+[unsafe]
+pub fn (mut ss Screenshot) free() {
+	unsafe {
+		free(ss.pixels)
+		ss.pixels = &byte(0)
+	}
+}
+
+// destroy - free the Screenshot pixels,
+// then free the screenshot data structure itself.
+[unsafe]
+pub fn (mut ss Screenshot) destroy() {
+	unsafe { ss.free() }
+	unsafe { free(ss) }
+}