From 030724a9aea346e4a9843d5842fb28c6d6c4cf1a Mon Sep 17 00:00:00 2001
From: Peter Fors <peter.fors@mindkiller.com>
Date: Thu, 9 Oct 2025 22:07:52 +0200
Subject: Rearrangement and refactoring and optimizations and more accuracy

---
 fragment_shader.glsl | 149 ---------------------------------------------------
 1 file changed, 149 deletions(-)
 delete mode 100644 fragment_shader.glsl

(limited to 'fragment_shader.glsl')

diff --git a/fragment_shader.glsl b/fragment_shader.glsl
deleted file mode 100644
index c21b2de..0000000
--- a/fragment_shader.glsl
+++ /dev/null
@@ -1,149 +0,0 @@
-// Specify default precision for fragment shaders
-
-out vec4 outcolor;
-in vec2 frag_texture_coord;
-
-uniform vec2 resolution;
-uniform vec2 src_image_size;
-uniform float brightness;
-uniform vec4 tone_data;
-uniform bool crt_emulation;
-uniform sampler2D iChannel0;
-
-vec3 CrtsFetch(vec2 uv) {
-	const float bias = 0.003333333;
-	return max(texture(iChannel0, uv, -16.0).rgb, vec3(bias));
-}
-
-#define CrtsRcpF1(x) (1.0 / (x))
-#define CrtsSatF1(x) clamp((x), 0.0, 1.0)
-const float PI2 = 6.28318530717958;
-const float HALF = 0.5;
-
-float CrtsMax3F1(float a, float b, float c) {
-	return max(a, max(b, c));
-}
-
-vec3 CrtsMask(vec2 pos, float dark) {
-	#ifdef CRTS_MASK_GRILLE
-		vec3 m = vec3(dark);
-		float x = fract(pos.x * (1.0 / 3.0));
-		m.r = (x < (1.0 / 3.0)) ? 1.0 : dark;
-		m.g = (x >= (1.0 / 3.0) && x < (2.0 / 3.0)) ? 1.0 : dark;
-		m.b = (x >= (2.0 / 3.0)) ? 1.0 : dark;
-		return m;
-	#endif
-
-	#ifdef CRTS_MASK_GRILLE_LITE
-		vec3 m = vec3(1.0);
-		float x = fract(pos.x * (1.0 / 3.0));
-		m.r = (x < (1.0 / 3.0)) ? dark : 1.0;
-		m.g = (x >= (1.0 / 3.0) && x < (2.0 / 3.0)) ? dark : 1.0;
-		m.b = (x >= (2.0 / 3.0)) ? dark : 1.0;
-		return m;
-	#endif
-
-	#ifdef CRTS_MASK_NONE
-		return vec3(1.0);
-	#endif
-
-	#ifdef CRTS_MASK_SHADOW
-		pos.x += pos.y * 3.0;
-		vec3 m = vec3(dark);
-		float x = fract(pos.x * (1.0 / 6.0));
-		m.r = (x < (1.0 / 3.0)) ? 1.0 : dark;
-		m.g = (x >= (1.0 / 3.0) && x < (2.0 / 3.0)) ? 1.0 : dark;
-		m.b = (x >= (2.0 / 3.0)) ? 1.0 : dark;
-		return m;
-	#endif
-}
-
-vec3 CrtsFilter(vec2 ipos, vec2 inputSizeDivOutputSize, vec2 halfInputSize, vec2 rcpInputSize, vec2 rcpOutputSize, vec2 twoDivOutputSize, float inputHeight, vec2 warp, float thin, float blur, float mask, vec4 tone) {
-	vec2 pos = ipos * twoDivOutputSize - vec2(1.0);
-	pos *= vec2(1.0 + (pos.y * pos.y) * warp.x, 1.0 + (pos.x * pos.x) * warp.y);
-	float vin = 1.0 - ((1.0 - CrtsSatF1(pos.x * pos.x)) * (1.0 - CrtsSatF1(pos.y * pos.y)));
-	vin = CrtsSatF1((-vin) * inputHeight + inputHeight);
-	pos = pos * halfInputSize + halfInputSize;
-
-	float y0 = floor(pos.y - 0.5) + 0.5;
-	float x0 = floor(pos.x - 1.5) + 0.5;
-	vec2 p = vec2(x0 * rcpInputSize.x, y0 * rcpInputSize.y);
-
-	vec3 colA[4], colB[4];
-	for (int i = 0; i < 4; i++) {
-		colA[i] = CrtsFetch(p);
-		p.x += rcpInputSize.x;
-	}
-	p.y += rcpInputSize.y;
-	for (int i = 3; i >= 0; i--) {
-		p.x -= rcpInputSize.x;
-		colB[i] = CrtsFetch(p);
-	}
-
-	float off = pos.y - y0;
-	float scanA = cos(min(HALF, off * thin) * PI2) * HALF + HALF;
-	float scanB = cos(min(HALF, (-off) * thin + thin) * PI2) * HALF + HALF;
-
-	float off0 = pos.x - x0;
-	float pix[4];
-	for (int i = 0; i < 4; i++) {
-		float diff = off0 - float(i);
-		pix[i] = exp2(blur * diff * diff);
-	}
-	float pixT = CrtsRcpF1(pix[0] + pix[1] + pix[2] + pix[3]);
-
-	#ifdef CRTS_WARP
-		pixT *= vin;
-	#endif
-
-	scanA *= pixT;
-	scanB *= pixT;
-
-	vec3 color = (colA[0] * pix[0] + colA[1] * pix[1] + colA[2] * pix[2] + colA[3] * pix[3]) * scanA + (colB[0] * pix[0] + colB[1] * pix[1] + colB[2] * pix[2] + colB[3] * pix[3]) * scanB;
-	color *= CrtsMask(ipos, mask);
-
-	#ifdef CRTS_TONE
-		float peak = max(1.0 / (256.0 * 65536.0), CrtsMax3F1(color.r, color.g, color.b));
-		vec3 ratio = color * CrtsRcpF1(peak);
-		#ifdef CRTS_CONTRAST
-			peak = pow(peak, tone.x);
-		#endif
-		peak = peak * CrtsRcpF1(peak * tone.y + tone.z);
-		#ifdef CRTS_SATURATION
-			ratio = pow(ratio, vec3(tone.w));
-		#endif
-		return ratio * peak;
-	#else
-		return color;
-	#endif
-}
-
-vec3 linearToSRGB(vec3 color) {
-	return pow(color, vec3(1.0 / 2.2));
-}
-
-void main() {
-	vec2 fragCoord = vec2(frag_texture_coord.x, 1.0 - frag_texture_coord.y);
-	if (crt_emulation) {
-		outcolor.rgb = CrtsFilter(
-			fragCoord.xy * resolution,
-			src_image_size / resolution,
-			src_image_size * vec2(0.5),
-			1.0 / src_image_size,
-			1.0 / resolution,
-			2.0 / resolution,
-			src_image_size.y,
-			vec2(1.0 / 24.0, 1.0 / 16.0),	// warp value
-			INPUT_THIN,
-			INPUT_BLUR,
-			INPUT_MASK,
-			tone_data
-		);
-
-		outcolor.rgb *= brightness;
-		outcolor = vec4(outcolor.rgb, 1.0); // Keep original color with alpha set to 1.0
-
-	} else {
-		outcolor = texture(iChannel0, fragCoord);
-	}
-}
-- 
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