TV rotation

cartridges can control TV rotation if necessary. only movie cart does
this for now

alt + <cursor keys> manually flips the screen rotation

environment/environment.go

@@ -18,6 +18,7 @@ package environment
 import (
 	"github.com/jetsetilly/gopher2600/hardware/preferences"
 	"github.com/jetsetilly/gopher2600/hardware/television"
+	"github.com/jetsetilly/gopher2600/hardware/television/specification"
 	"github.com/jetsetilly/gopher2600/random"
 )
 
@@ -28,6 +29,7 @@ type Label string
 // implementation
 type Television interface {
 	GetSpecID() string
+	SetRotation(specification.Rotation)
 }
 
 // Environment is used to provide context for an emulation. Particularly useful

gui/sdlimgui/glsl_crtseq.go

@@ -18,6 +18,7 @@ package sdlimgui
 import (
 	"github.com/jetsetilly/gopher2600/gui/crt"
 	"github.com/jetsetilly/gopher2600/gui/sdlimgui/framebuffer"
+	"github.com/jetsetilly/gopher2600/hardware/television/specification"
 )
 
 type crtSeqPrefs struct {
@@ -163,7 +164,8 @@ func (sh *crtSequencer) flushPhosphor() {
 //
 // integerScaling instructs the scaling shader not to perform any smoothing
 func (sh *crtSequencer) process(env shaderEnvironment, moreProcessing bool,
-	numScanlines int, numClocks int, image textureSpec, prefs crtSeqPrefs) uint32 {
+	numScanlines int, numClocks int, rotation specification.Rotation,
+	image textureSpec, prefs crtSeqPrefs) uint32 {
 
 	// we'll be chaining many shaders together so use internal projection
 	env.useInternalProj = true
@@ -239,12 +241,12 @@ func (sh *crtSequencer) process(env shaderEnvironment, moreProcessing bool,
 			// leaves pixels from a previous shader in the texture.
 			sh.seq.Clear(crtSeqMore)
 			env.srcTextureID = sh.seq.Process(crtSeqMore, func() {
-				sh.effectsShaderFlipped.(*crtSeqEffectsShader).setAttributesArgs(env, numScanlines, numClocks, prefs)
+				sh.effectsShaderFlipped.(*crtSeqEffectsShader).setAttributesArgs(env, numScanlines, numClocks, rotation, prefs)
 				env.draw()
 			})
 		} else {
 			env.useInternalProj = false
-			sh.effectsShader.(*crtSeqEffectsShader).setAttributesArgs(env, numScanlines, numClocks, prefs)
+			sh.effectsShader.(*crtSeqEffectsShader).setAttributesArgs(env, numScanlines, numClocks, rotation, prefs)
 		}
 	} else {
 		if moreProcessing {

gui/sdlimgui/glsl_crtseq_effects.go

@@ -20,6 +20,7 @@ import (
 
 	"github.com/go-gl/gl/v3.2-core/gl"
 	"github.com/jetsetilly/gopher2600/gui/sdlimgui/shaders"
+	"github.com/jetsetilly/gopher2600/hardware/television/specification"
 )
 
 type crtSeqEffectsShader struct {
@@ -47,6 +48,7 @@ type crtSeqEffectsShader struct {
 	noiseLevel           int32
 	fringingAmount       int32
 	time                 int32
+	rotation             int32
 }
 
 func newCrtSeqEffectsShader(yflip bool) shaderProgram {
@@ -79,13 +81,16 @@ func newCrtSeqEffectsShader(yflip bool) shaderProgram {
 	sh.noiseLevel = gl.GetUniformLocation(sh.handle, gl.Str("NoiseLevel"+"\x00"))
 	sh.fringingAmount = gl.GetUniformLocation(sh.handle, gl.Str("FringingAmount"+"\x00"))
 	sh.time = gl.GetUniformLocation(sh.handle, gl.Str("Time"+"\x00"))
+	sh.rotation = gl.GetUniformLocation(sh.handle, gl.Str("Rotation"+"\x00"))
 
 	return sh
 }
 
 // most shader attributes can be discerened automatically but number of
 // scanlines, clocks and whether to add noise to the image is context sensitive.
-func (sh *crtSeqEffectsShader) setAttributesArgs(env shaderEnvironment, numScanlines int, numClocks int, prefs crtSeqPrefs) {
+func (sh *crtSeqEffectsShader) setAttributesArgs(env shaderEnvironment,
+	numScanlines int, numClocks int, rotation specification.Rotation, prefs crtSeqPrefs) {
+
 	sh.shader.setAttributes(env)
 
 	gl.Uniform2f(sh.screenDim, float32(env.width), float32(env.height))
@@ -110,4 +115,5 @@ func (sh *crtSeqEffectsShader) setAttributesArgs(env shaderEnvironment, numScanl
 	gl.Uniform1f(sh.noiseLevel, float32(prefs.NoiseLevel))
 	gl.Uniform1f(sh.fringingAmount, float32(prefs.FringingAmount))
 	gl.Uniform1f(sh.time, float32(time.Now().Nanosecond())/100000000.0)
+	gl.Uniform1i(sh.rotation, int32(rotation))
 }

gui/sdlimgui/glsl_dbgscr.go

@@ -205,7 +205,7 @@ func (sh *dbgScrShader) setAttributes(env shaderEnvironment) {
 		prefs.Bevel = false
 
 		env.srcTextureID = sh.crt.process(env, true,
-			sh.img.wm.dbgScr.numScanlines, specification.ClksVisible,
+			sh.img.wm.dbgScr.numScanlines, specification.ClksVisible, specification.NormalRotation,
 			sh.img.wm.dbgScr, prefs)
 	} else {
 		// if crtPreview is disabled we still go through the crt process. we do
@@ -223,7 +223,7 @@ func (sh *dbgScrShader) setAttributes(env shaderEnvironment) {
 		prefs.Enabled = false
 
 		env.srcTextureID = sh.crt.process(env, true,
-			sh.img.wm.dbgScr.numScanlines, specification.ClksVisible,
+			sh.img.wm.dbgScr.numScanlines, specification.ClksVisible, specification.NormalRotation,
 			sh.img.wm.dbgScr, prefs)
 	}
 

gui/sdlimgui/glsl_playscr.go

@@ -64,6 +64,6 @@ func (sh *playscrShader) setAttributes(env shaderEnvironment) {
 	sh.screenshot.process(env, sh.img.playScr)
 
 	sh.crt.process(env, false,
-		sh.img.playScr.visibleScanlines, specification.ClksVisible,
+		sh.img.playScr.visibleScanlines, specification.ClksVisible, sh.img.screen.rotation.Load().(specification.Rotation),
 		sh.img.playScr, newCrtSeqPrefs(sh.img.crtPrefs))
 }

gui/sdlimgui/glsl_screenshot.go

@@ -180,7 +180,7 @@ func (sh *screenshotSequencer) crtProcess(env shaderEnvironment, scalingImage te
 	}
 
 	textureID := sh.crt.process(env, true,
-		sh.img.playScr.visibleScanlines, specification.ClksVisible,
+		sh.img.playScr.visibleScanlines, specification.ClksVisible, sh.img.screen.rotation.Load().(specification.Rotation),
 		sh.img.playScr, prefs)
 
 	// reduce exposure count and return if there is still more to do
@@ -352,7 +352,7 @@ func (sh *screenshotSequencer) compositeFinalise(env shaderEnvironment, composit
 
 	// pass composite image through CRT shaders
 	textureID := sh.crt.process(env, true,
-		sh.img.playScr.visibleScanlines, specification.ClksVisible,
+		sh.img.playScr.visibleScanlines, specification.ClksVisible, sh.img.screen.rotation.Load().(specification.Rotation),
 		sh, newCrtSeqPrefs(sh.img.crtPrefs))
 	gl.BindTexture(gl.TEXTURE_2D, textureID)
 

gui/sdlimgui/playscr.go

@@ -22,6 +22,7 @@ import (
 	"github.com/go-gl/gl/v3.2-core/gl"
 	"github.com/inkyblackness/imgui-go/v4"
 	"github.com/jetsetilly/gopher2600/gui/fonts"
+	"github.com/jetsetilly/gopher2600/hardware/television/specification"
 )
 
 // note that values from the lazy package will not be updated in the service
@@ -248,12 +249,20 @@ func (win *playScr) render() {
 
 // must be called from with a critical section.
 func (win *playScr) setScaling() {
+	rot := win.scr.rotation.Load().(specification.Rotation)
+
 	sz := win.img.plt.displaySize()
-	screenRegion := imgui.Vec2{sz[0], sz[1]}
+	screenRegion := imgui.Vec2{X: sz[0], Y: sz[1]}
 
 	w := float32(win.scr.crit.cropPixels.Bounds().Size().X)
 	h := float32(win.scr.crit.cropPixels.Bounds().Size().Y)
-	adjW := w * pixelWidth * win.scr.crit.frameInfo.Spec.AspectBias
+
+	adj := win.scr.crit.frameInfo.Spec.AspectBias
+	if rot == specification.NormalRotation || rot == specification.FlippedRotation {
+		adj *= pixelWidth
+	}
+
+	adjW := w * adj
 
 	var scaling float32
 
@@ -285,7 +294,7 @@ func (win *playScr) setScaling() {
 	win.imagePosMax = screenRegion.Minus(win.imagePosMin)
 
 	win.yscaling = scaling
-	win.xscaling = scaling * pixelWidth * win.scr.crit.frameInfo.Spec.AspectBias
+	win.xscaling = scaling * adj
 	win.scaledWidth = w * win.xscaling
 	win.scaledHeight = h * win.yscaling
 

gui/sdlimgui/screen.go

@@ -19,6 +19,7 @@ import (
 	"image"
 	"image/color"
 	"sync"
+	"sync/atomic"
 
 	"github.com/jetsetilly/gopher2600/coprocessor"
 	"github.com/jetsetilly/gopher2600/debugger/govern"
@@ -45,6 +46,10 @@ type screen struct {
 
 	crit screenCrit
 
+	// atmoic access of rotation value. it's more convenient to be able to
+	// access this atomically, rather than via the screenCrit type
+	rotation atomic.Value // specification.Rotation
+
 	// list of renderers to call from render. renderers are added with
 	// addTextureRenderer()
 	renderers  []textureRenderer
@@ -183,6 +188,7 @@ func newScreen(img *SdlImgui) *screen {
 		emuWaitAck: make(chan bool),
 	}
 
+	scr.rotation.Store(specification.NormalRotation)
 	scr.crit.section.Lock()
 
 	scr.crit.overlay = reflection.OverlayLabels[reflection.OverlayNone]
@@ -214,7 +220,19 @@ func newScreen(img *SdlImgui) *screen {
 	return scr
 }
 
-// SetFPSCap implements the television.FPSCap interface
+// SetFPSCap implements the television.PixelRendererRotation interface
+func (scr *screen) SetRotation(rotation specification.Rotation) {
+	scr.rotation.Store(rotation)
+
+	scr.crit.section.Lock()
+	defer scr.crit.section.Unlock()
+
+	// the only other component that needs to be aware of the rotation is the
+	// play screen
+	scr.img.playScr.resize()
+}
+
+// SetFPSCap implements the television.PixelRendererFPSCap interface
 func (scr *screen) SetFPSCap(limit bool) {
 	scr.crit.section.Lock()
 	defer scr.crit.section.Unlock()

gui/sdlimgui/service_keyboard.go

@@ -23,6 +23,7 @@ import (
 
 	"github.com/inkyblackness/imgui-go/v4"
 	"github.com/jetsetilly/gopher2600/debugger/govern"
+	"github.com/jetsetilly/gopher2600/hardware/television/specification"
 	"github.com/jetsetilly/gopher2600/logger"
 	"github.com/jetsetilly/gopher2600/notifications"
 	"github.com/jetsetilly/gopher2600/userinput"
@@ -35,6 +36,7 @@ func (img *SdlImgui) serviceKeyboard(ev *sdl.KeyboardEvent) {
 	}
 
 	ctrl := ev.Keysym.Mod&sdl.KMOD_LCTRL == sdl.KMOD_LCTRL || ev.Keysym.Mod&sdl.KMOD_RCTRL == sdl.KMOD_RCTRL
+	alt := ev.Keysym.Mod&sdl.KMOD_LALT == sdl.KMOD_LALT || ev.Keysym.Mod&sdl.KMOD_RALT == sdl.KMOD_RALT
 	shift := ev.Keysym.Mod&sdl.KMOD_LSHIFT == sdl.KMOD_LSHIFT || ev.Keysym.Mod&sdl.KMOD_RSHIFT == sdl.KMOD_RSHIFT
 
 	// enable window searching based on keyboard modifiers
@@ -79,6 +81,23 @@ func (img *SdlImgui) serviceKeyboard(ev *sdl.KeyboardEvent) {
 					img.quit()
 				}
 
+			case sdl.SCANCODE_LEFT:
+				if alt {
+					img.screen.SetRotation(specification.LeftRotation)
+				}
+			case sdl.SCANCODE_RIGHT:
+				if alt {
+					img.screen.SetRotation(specification.RightRotation)
+				}
+			case sdl.SCANCODE_UP:
+				if alt {
+					img.screen.SetRotation(specification.NormalRotation)
+				}
+			case sdl.SCANCODE_DOWN:
+				if alt {
+					img.screen.SetRotation(specification.FlippedRotation)
+				}
+
 			default:
 				handled = false
 			}

gui/sdlimgui/shaders/crt_effects.frag

@@ -36,6 +36,8 @@ uniform float NoiseLevel;
 uniform float FringingAmount;
 uniform float Time;
 
+// rotation values are the values in hardware/television/specification/rotation.go
+uniform int Rotation;
 
 // Gold Noise taken from: https://www.shadertoy.com/view/ltB3zD
 // Coprighted to dcerisano@standard3d.com not sure of the licence
@@ -108,12 +110,31 @@ void main() {
 		uv = mix(curve(uv), uv, m);
 	}
 
-	// bevel (if in use) should bend the same as the screen
+	// shineUV are the coordinates we use when applying the shine effect. we
+	// don't want this to be rotated
+	vec2 shineUV = uv;
+
+	// apply rotation
+	float textureRatio = ScreenDim.x / ScreenDim.y;
+	float rads = 1.5708 * Rotation;
+	uv -= 0.5;
+	/* if (mod(Rotation, 2) == 1) { */
+	/* 	uv.x /= 0.5; */
+	/* } */
+    uv = vec2(
+        cos(rads) * uv.x + sin(rads) * uv.y,
+        cos(rads) * uv.y - sin(rads) * uv.x
+    );
+	uv += 0.5;
+
+	// bevel (if in use) should be curved and rotated the same as the screen texture
 	vec2 uv_bevel = uv;
 
-	// reduce size of main display if bevel is active
+	// reduce size of main texture and shine if bevel is active. note that we don't reduce
+	// the size of the bevel but we do rotate it later
 	if (Bevel == 1) {
 		uv = (uv - 0.5) * 1.1 + 0.5;
+		shineUV = (shineUV - 0.5) * 1.1 + 0.5;
 	}
 
 	// after this point every UV reference is to the curved UV
@@ -211,8 +232,8 @@ void main() {
 
 	// shine affect
 	if (Shine == 1) {
-		vec2 uv_shine = (uv - 0.5) * 1.2 + 0.5;
-		float shine = (1.0-uv_shine.s)*(1.0-uv_shine.t);
+		vec2 shineUV = (shineUV - 0.5) * 1.2 + 0.5;
+		float shine = (1.0-shineUV.s)*(1.0-shineUV.t);
 		Crt_Color = mix(Crt_Color, vec4(1.0), shine*0.05);
 	}
 

hardware/memory/cartridge/moviecart/moviecart.go

@@ -23,6 +23,7 @@ import (
 	"github.com/jetsetilly/gopher2600/environment"
 	"github.com/jetsetilly/gopher2600/hardware/memory/cartridge/mapper"
 	"github.com/jetsetilly/gopher2600/hardware/memory/memorymap"
+	"github.com/jetsetilly/gopher2600/hardware/television/specification"
 	"github.com/jetsetilly/gopher2600/logger"
 )
 
@@ -198,6 +199,9 @@ type state struct {
 
 	// the stream has failed because bad data has been encountered
 	streamFail bool
+
+	// the most recent rotation instruction. can only ever changes for version 2 streams
+	rotation byte
 }
 
 // what part of the OSD is currently being display.
@@ -285,6 +289,10 @@ func NewMoviecart(env *environment.Environment, loader cartridgeloader.Loader) (
 	// field starts off in the end position
 	cart.state.streamIndex = 1
 
+	// read next field straight away. this has the advantage of triggering the
+	// first screen rotation in time for the attract screen
+	cart.nextField()
+
 	return cart, nil
 }
 
@@ -887,6 +895,21 @@ func (cart *Moviecart) nextField() {
 	// version number
 	switch cart.state.streamBuffer[cart.state.streamIndex][4] & 0x80 {
 	case 0x80:
+		rotation := cart.state.streamBuffer[cart.state.streamIndex][4] & 0b11
+		if rotation != cart.state.rotation {
+			switch rotation {
+			case 0b00:
+				cart.env.TV.SetRotation(specification.NormalRotation)
+			case 0b01:
+				cart.env.TV.SetRotation(specification.RightRotation)
+			case 0b10:
+				cart.env.TV.SetRotation(specification.FlippedRotation)
+			case 0b11:
+				cart.env.TV.SetRotation(specification.LeftRotation)
+			}
+			cart.state.rotation = rotation
+		}
+
 		cart.state.format[cart.state.streamIndex].vsync = byte(cart.state.streamBuffer[cart.state.streamIndex][9])
 		cart.state.format[cart.state.streamIndex].vblank = byte(cart.state.streamBuffer[cart.state.streamIndex][10])
 		cart.state.format[cart.state.streamIndex].overscan = byte(cart.state.streamBuffer[cart.state.streamIndex][11])

hardware/television/protocol.go

@@ -17,6 +17,7 @@ package television
 
 import (
 	"github.com/jetsetilly/gopher2600/hardware/television/signal"
+	"github.com/jetsetilly/gopher2600/hardware/television/specification"
 )
 
 // PixelRenderer implementations displays, or otherwise works with, visual
@@ -96,9 +97,17 @@ type PixelRenderer interface {
 	EndRendering() error
 }
 
+// PixelRendererRotation is an extension to the PixelRenderer interface. Pixel
+// renderes that implement this interface can show the television image in a
+// rotated aspect. Not all pixel renderers need to worry about rotation.
+type PixelRendererRotation interface {
+	SetRotation(specification.Rotation)
+}
+
 // PixelRendererFPSCap is an extension to the PixelRenderer interface. Pixel
 // renderers that implement this interface will be notified when the
-// television's frame capping policy is changed
+// television's frame capping policy is changed. Not all pixel renderers need to
+// worry about frame rate.
 type PixelRendererFPSCap interface {
 	SetFPSCap(limit bool)
 }