FlipY texture flag, display world texture atlas

internal/igwrap/backend/shader.frag

@@ -8,6 +8,7 @@
 
 #define FLAG_LINEAR     (1<<4)
 #define FLAG_IMGUI_FONT (1<<5)
+#define FLAG_FLIP_Y     (1<<6)
 
 uniform sampler2D tex;
 uniform int flags;

internal/igwrap/backend/shader.vert

@@ -1,6 +1,17 @@
 #version 330
 
+#define FLAG_RED    (1<<0)
+#define FLAG_GREEN  (1<<1)
+#define FLAG_BLUE   (1<<2)
+#define FLAG_ALPHA  (1<<3)
+#define FLAG_COLORS (FLAG_RED | FLAG_GREEN | FLAG_BLUE | FLAG_ALPHA)
+
+#define FLAG_LINEAR     (1<<4)
+#define FLAG_IMGUI_FONT (1<<5)
+#define FLAG_FLIP_Y     (1<<6)
+
 uniform mat4 projection;
+uniform int flags;
 
 in vec2 pos;
 in vec2 uv;
@@ -13,5 +24,8 @@ void main() {
 	fragUV = uv;
 	fragColor = color;
     gl_Position = projection * vec4(pos.xy, 0, 1);
+
+	if ((flags & FLAG_FLIP_Y) != 0)
+		fragUV.y = 1 - fragUV.y;
 }
 

internal/igwrap/imagewrap.go

@@ -38,6 +38,7 @@ func ImageV(tex uint32, size itype.Vec2f, texRange itype.Rectf, texColor itype.V
 	)
 }
 
+// Per-texture flags. This is passed to the shader as-is and handled only there.
 type TextureFlag int
 
 const (
@@ -48,6 +49,7 @@ const (
 
 	TextureFlag_Linear    // Linear source data, requires gamma correction.
 	TextureFlag_ImGUIFont // This is a font texture from ImGUI, with a single red channel.
+	TextureFlag_FlipY     // The render should flip the Y axis of the texture. By default ImageXXX()s render textures with (0,0) at the bottom left, and this is for in case you want to flip them.
 
 	TextureFlag_RGB  = TextureFlag_Red | TextureFlag_Green | TextureFlag_Blue
 	TextureFlag_RGBA = TextureFlag_Red | TextureFlag_Green | TextureFlag_Blue | TextureFlag_Alpha
@@ -70,6 +72,18 @@ func SetTextureFlag(tex uint32, flags ...TextureFlag) {
 	texflags[tex] = f
 }
 
+// AddTextureFlag adds the given flags to the texture.
+func AddTextureFlag(tex uint32, flags ...TextureFlag) {
+	var f TextureFlag
+	for _, f0 := range flags {
+		f |= f0
+	}
+
+	texflagslock.Lock()
+	defer texflagslock.Unlock()
+	texflags[tex] |= f
+}
+
 // TextureFlag returns the flags of a given texture.
 func GetTextureFlag(tex uint32) TextureFlag {
 	texflagslock.RLock()

internal/igwrap/wrap.go

@@ -7,6 +7,10 @@ import (
 	"github.com/inkyblackness/imgui-go/v4"
 )
 
+const (
+	WindowFlagsOverlay imgui.WindowFlags = imgui.WindowFlagsAlwaysAutoResize | imgui.WindowFlagsNoBackground | imgui.WindowFlagsNoNavFocus | imgui.WindowFlagsNoNavInputs | imgui.WindowFlagsNoDecoration | imgui.WindowFlagsNoBringToFrontOnFocus | imgui.WindowFlagsNoSavedSettings | imgui.WindowFlagsNoFocusOnAppearing
+)
+
 // MenuItem wraps imgui.MenuItemV to create a
 // easy-to-use and intuitive interface.
 func MenuItem(name, shortcut string, selected *bool, enabled bool) {
@@ -21,11 +25,18 @@ func Text(format string, a ...interface{}) {
 	imgui.Text(fmt.Sprintf(format, a...))
 }
 
-// TextBackground wraps imgui.Text to create a
-// shortcut for fmt.Sprintf.
+// TextBackground wraps imgui.Text to create a shortcut for fmt.Sprintf.
+//
+// It also fills the background of the text with half-transparant black, and takes care of the padding.
+func TextBackground(format string, a ...interface{}) {
+	pad := Vec2f(imgui.CurrentStyle().ItemSpacing())
+	TextBackgroundV(itype.Vec4f{0, 0, 0, 0.5}, pad, format, a...)
+}
+
+// TextBackgroundV wraps imgui.Text to create a shortcut for fmt.Sprintf.
 //
 // It also fills the background of the text with the given color.
-func TextBackground(color itype.Vec4f, padding itype.Vec2f, format string, a ...interface{}) {
+func TextBackgroundV(color itype.Vec4f, padding itype.Vec2f, format string, a ...interface{}) {
 	text := fmt.Sprintf(format, a...)
 	orig := imgui.CursorScreenPos()
 	size := imgui.CalcTextSize(text, false, 0)
@@ -35,6 +46,12 @@ func TextBackground(color itype.Vec4f, padding itype.Vec2f, format string, a ...
 	imgui.Text(text)
 }
 
+// TextBlank blanks a line with a nice-looking height (half the font height plus paddings).
+func TextBlank() {
+	fontSize := imgui.FontSize()
+	imgui.Dummy(imgui.Vec2{X: fontSize / 2, Y: fontSize / 2})
+}
+
 // Begin wraps imgui.BeginV to create a
 // easy-to-use and intuitive interface.
 //