Improve shader

1 files changed, 20 insertions, 44 deletions

diff --git a/mat_palette.gdshader b/mat_palette.gdshader
index e24a6ee..03c664a 100644
--- a/mat_palette.gdshader
+++ b/mat_palette.gdshader
@@ -1,54 +1,30 @@
 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;
+uniform sampler2D screen_texture : hint_screen_texture, repeat_disable, filter_nearest;
 
-const int N_COLORS = 12;
-
-uniform sampler2D screen_texture : hint_screen_texture;
+uniform float brightness : hint_range(-1, 1) = 0;
+uniform sampler2D source_palette;
+uniform sampler2D target_palette;
 
 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]; }
-	}
+	ivec2 pal_size = textureSize(source_palette, 0);
 	
-	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;
+	float color_diff = 1.0;
+	int nearest_swatch = 0;
+		
+	for (int swatch=0; swatch < pal_size.x; swatch++) {
+		vec4 sampled_color = texelFetch(source_palette, ivec2(swatch,0), 0);
+		float new_color_diff = distance(sampled_color, screen_color);
+		
+		if (new_color_diff < color_diff) {
+			color_diff = new_color_diff;
+			nearest_swatch = swatch;
 		}
 	}
-	*/
-	COLOR = vec4(result.rgb, COLOR.a);
+	
+	int swatch_offset = int(brightness * float(pal_size.x));
+	int target_swatch = clamp(nearest_swatch + swatch_offset, 0, pal_size.x -1);
+	
+	COLOR = texelFetch(target_palette, ivec2(target_swatch, 0), 0);
 }
-
-//void light() {
-//	// Called for every pixel for every light affecting the CanvasItem.
-//	// Uncomment to replace the default light processing function with this one.
-//}