Add some screen shader stuff

1 files changed, 54 insertions, 0 deletions

diff --git a/mat_palette.gdshader b/mat_palette.gdshader
new file mode 100644
index 0000000..e24a6ee
--- /dev/null
+++ b/mat_palette.gdshader
@@ -0,0 +1,54 @@
+shader_type canvas_item;
+
+uniform vec4 palette_0  : source_color;
+uniform vec4 palette_1  : source_color;
+uniform vec4 palette_2  : source_color;
+uniform vec4 palette_3  : source_color;
+uniform vec4 palette_4  : source_color;
+uniform vec4 palette_5  : source_color;
+uniform vec4 palette_6  : source_color;
+uniform vec4 palette_7  : source_color;
+uniform vec4 palette_8  : source_color;
+uniform vec4 palette_9  : source_color;
+uniform vec4 palette_10 : source_color;
+uniform vec4 palette_11 : source_color;
+
+const int N_COLORS = 12;
+
+uniform sampler2D screen_texture : hint_screen_texture;
+
+void fragment() {
+	vec4 palette[N_COLORS] = { palette_0, palette_1, palette_2, palette_3, palette_4, palette_5, palette_6, palette_7, palette_8, palette_9, palette_10, palette_11 };
+	vec4 screen_color = texture(screen_texture, SCREEN_UV);
+	// Compute source color value
+	float sv = 0.f;
+	for (int i = 0; i < 3; i++) {
+		if (screen_color[i] > sv) { sv = screen_color[i]; }
+	}
+	
+	int pal_i = int(floor((sv * 0.99f) * float(N_COLORS)));
+	vec4 result = palette[pal_i];
+	/*
+	float min_dist = 999.f; // always bigger than 1.0
+	vec4 result;
+	for (int i = 0; i < N_COLORS; i++) {
+		vec4 pc = palette[i];
+		// Compute palette color value
+		float pv = 0.f;
+		for (int j = 0; j < 3; j++) {
+			if (pc[j] > pv) { pv = pc[j]; }
+		}
+		float dist = abs(pv - sv);
+		if (dist < min_dist) {
+			min_dist = dist;
+			result = pc;
+		}
+	}
+	*/
+	COLOR = vec4(result.rgb, COLOR.a);
+}
+
+//void light() {
+//	// Called for every pixel for every light affecting the CanvasItem.
+//	// Uncomment to replace the default light processing function with this one.
+//}