Implement DOF blur, Glow, and BCS in GLES2

6 files changed, 290 insertions, 271 deletions

diff --git a/drivers/gles2/shaders/SCsub b/drivers/gles2/shaders/SCsub
index 085c43319c..d7ae0243e6 100644
--- a/drivers/gles2/shaders/SCsub
+++ b/drivers/gles2/shaders/SCsub
@@ -12,12 +12,12 @@ if 'GLES2_GLSL' in env['BUILDERS']:
     env.GLES2_GLSL('cube_to_dp.glsl');
 #    env.GLES2_GLSL('blend_shape.glsl');
 #    env.GLES2_GLSL('screen_space_reflection.glsl');
-#    env.GLES2_GLSL('effect_blur.glsl');
+    env.GLES2_GLSL('effect_blur.glsl');
 #    env.GLES2_GLSL('subsurf_scattering.glsl');
 #    env.GLES2_GLSL('ssao.glsl');
 #    env.GLES2_GLSL('ssao_minify.glsl');
 #    env.GLES2_GLSL('ssao_blur.glsl');
 #    env.GLES2_GLSL('exposure.glsl');
-#    env.GLES2_GLSL('tonemap.glsl');
+    env.GLES2_GLSL('tonemap.glsl');
 #    env.GLES2_GLSL('particles.glsl');
     env.GLES2_GLSL('lens_distorted.glsl');
diff --git a/drivers/gles2/shaders/canvas_shadow.glsl b/drivers/gles2/shaders/canvas_shadow.glsl
index dcb43d523f..7a5ba4f571 100644
--- a/drivers/gles2/shaders/canvas_shadow.glsl
+++ b/drivers/gles2/shaders/canvas_shadow.glsl
@@ -34,9 +34,14 @@ void main() {
 #define mediump
 #define highp
 #else
+#if defined(USE_HIGHP_PRECISION)
+precision highp float;
+precision highp int;
+#else
 precision mediump float;
 precision mediump int;
 #endif
+#endif
 
 varying highp vec4 position_interp;
 /* clang-format on */
diff --git a/drivers/gles2/shaders/cube_to_dp.glsl b/drivers/gles2/shaders/cube_to_dp.glsl
index cb4b3f6dec..769908c3b4 100644
--- a/drivers/gles2/shaders/cube_to_dp.glsl
+++ b/drivers/gles2/shaders/cube_to_dp.glsl
@@ -30,9 +30,14 @@ void main() {
 #define mediump
 #define highp
 #else
+#if defined(USE_HIGHP_PRECISION)
+precision highp float;
+precision highp int;
+#else
 precision mediump float;
 precision mediump int;
 #endif
+#endif
 
 uniform highp samplerCube source_cube; //texunit:0
 /* clang-format on */
diff --git a/drivers/gles2/shaders/effect_blur.glsl b/drivers/gles2/shaders/effect_blur.glsl
index df79e89931..b28d78a6ca 100644
--- a/drivers/gles2/shaders/effect_blur.glsl
+++ b/drivers/gles2/shaders/effect_blur.glsl
@@ -1,11 +1,20 @@
 /* clang-format off */
 [vertex]
 
-layout(location = 0) in highp vec4 vertex_attrib;
+#ifdef USE_GLES_OVER_GL
+#define lowp
+#define mediump
+#define highp
+#else
+precision highp float;
+precision highp int;
+#endif
+
+attribute vec2 vertex_attrib; // attrib:0
 /* clang-format on */
-layout(location = 4) in vec2 uv_in;
+attribute vec2 uv_in; // attrib:4
 
-out vec2 uv_interp;
+varying vec2 uv_interp;
 
 #ifdef USE_BLUR_SECTION
 
@@ -16,7 +25,7 @@ uniform vec4 blur_section;
 void main() {
 
 	uv_interp = uv_in;
-	gl_Position = vertex_attrib;
+	gl_Position = vec4(vertex_attrib, 0.0, 1.0);
 #ifdef USE_BLUR_SECTION
 
 	uv_interp = blur_section.xy + uv_interp * blur_section.zw;
@@ -27,29 +36,46 @@ void main() {
 /* clang-format off */
 [fragment]
 
-#if !defined(GLES_OVER_GL)
+// texture2DLodEXT and textureCubeLodEXT are fragment shader specific.
+// Do not copy these defines in the vertex section.
+#ifndef USE_GLES_OVER_GL
+#ifdef GL_EXT_shader_texture_lod
+#extension GL_EXT_shader_texture_lod : enable
+#define texture2DLod(img, coord, lod) texture2DLodEXT(img, coord, lod)
+#define textureCubeLod(img, coord, lod) textureCubeLodEXT(img, coord, lod)
+#endif
+#endif // !USE_GLES_OVER_GL
+
+#ifdef GL_ARB_shader_texture_lod
+#extension GL_ARB_shader_texture_lod : enable
+#endif
+
+#if !defined(GL_EXT_shader_texture_lod) && !defined(GL_ARB_shader_texture_lod)
+#define texture2DLod(img, coord, lod) texture2D(img, coord, lod)
+#define textureCubeLod(img, coord, lod) textureCube(img, coord, lod)
+#endif
+
+#ifdef USE_GLES_OVER_GL
+#define lowp
+#define mediump
+#define highp
+#else
+#if defined(USE_HIGHP_PRECISION)
+precision highp float;
+precision highp int;
+#else
 precision mediump float;
+precision mediump int;
+#endif
 #endif
 
-in vec2 uv_interp;
+varying vec2 uv_interp;
 /* clang-format on */
 uniform sampler2D source_color; //texunit:0
 
-#ifdef SSAO_MERGE
-uniform sampler2D source_ssao; //texunit:1
-#endif
-
 uniform float lod;
 uniform vec2 pixel_size;
 
-layout(location = 0) out vec4 frag_color;
-
-#ifdef SSAO_MERGE
-
-uniform vec4 ssao_color;
-
-#endif
-
 #if defined(GLOW_GAUSSIAN_HORIZONTAL) || defined(GLOW_GAUSSIAN_VERTICAL)
 
 uniform float glow_strength;
@@ -58,6 +84,7 @@ uniform float glow_strength;
 
 #if defined(DOF_FAR_BLUR) || defined(DOF_NEAR_BLUR)
 
+#ifdef USE_GLES_OVER_GL
 #ifdef DOF_QUALITY_LOW
 const int dof_kernel_size = 5;
 const int dof_kernel_from = 2;
@@ -76,6 +103,7 @@ const int dof_kernel_size = 21;
 const int dof_kernel_from = 10;
 const float dof_kernel[21] = float[](0.028174, 0.032676, 0.037311, 0.041944, 0.046421, 0.050582, 0.054261, 0.057307, 0.059587, 0.060998, 0.061476, 0.060998, 0.059587, 0.057307, 0.054261, 0.050582, 0.046421, 0.041944, 0.037311, 0.032676, 0.028174);
 #endif
+#endif
 
 uniform sampler2D dof_source_depth; //texunit:1
 uniform float dof_begin;
@@ -83,24 +111,11 @@ uniform float dof_end;
 uniform vec2 dof_dir;
 uniform float dof_radius;
 
-#ifdef DOF_NEAR_BLUR_MERGE
-
-uniform sampler2D source_dof_original; //texunit:2
-#endif
-
 #endif
 
 #ifdef GLOW_FIRST_PASS
 
-uniform float exposure;
-uniform float white;
-
-#ifdef GLOW_USE_AUTO_EXPOSURE
-
-uniform highp sampler2D source_auto_exposure; //texunit:1
-uniform highp float auto_exposure_grey;
-
-#endif
+uniform highp float luminance_cap;
 
 uniform float glow_bloom;
 uniform float glow_hdr_threshold;
@@ -113,60 +128,95 @@ uniform float camera_z_near;
 
 void main() {
 
-#ifdef GAUSSIAN_HORIZONTAL
+#ifdef GLOW_GAUSSIAN_HORIZONTAL
 	vec2 pix_size = pixel_size;
 	pix_size *= 0.5; //reading from larger buffer, so use more samples
-	// sigma 2
-	vec4 color = textureLod(source_color, uv_interp + vec2(0.0, 0.0) * pix_size, lod) * 0.214607;
-	color += textureLod(source_color, uv_interp + vec2(1.0, 0.0) * pix_size, lod) * 0.189879;
-	color += textureLod(source_color, uv_interp + vec2(2.0, 0.0) * pix_size, lod) * 0.131514;
-	color += textureLod(source_color, uv_interp + vec2(3.0, 0.0) * pix_size, lod) * 0.071303;
-	color += textureLod(source_color, uv_interp + vec2(-1.0, 0.0) * pix_size, lod) * 0.189879;
-	color += textureLod(source_color, uv_interp + vec2(-2.0, 0.0) * pix_size, lod) * 0.131514;
-	color += textureLod(source_color, uv_interp + vec2(-3.0, 0.0) * pix_size, lod) * 0.071303;
-	frag_color = color;
+	vec4 color = texture2DLod(source_color, uv_interp + vec2(0.0, 0.0) * pix_size, lod) * 0.174938;
+	color += texture2DLod(source_color, uv_interp + vec2(1.0, 0.0) * pix_size, lod) * 0.165569;
+	color += texture2DLod(source_color, uv_interp + vec2(2.0, 0.0) * pix_size, lod) * 0.140367;
+	color += texture2DLod(source_color, uv_interp + vec2(3.0, 0.0) * pix_size, lod) * 0.106595;
+	color += texture2DLod(source_color, uv_interp + vec2(-1.0, 0.0) * pix_size, lod) * 0.165569;
+	color += texture2DLod(source_color, uv_interp + vec2(-2.0, 0.0) * pix_size, lod) * 0.140367;
+	color += texture2DLod(source_color, uv_interp + vec2(-3.0, 0.0) * pix_size, lod) * 0.106595;
+	color *= glow_strength;
+	gl_FragColor = color;
 #endif
 
-#ifdef GAUSSIAN_VERTICAL
-	vec4 color = textureLod(source_color, uv_interp + vec2(0.0, 0.0) * pixel_size, lod) * 0.38774;
-	color += textureLod(source_color, uv_interp + vec2(0.0, 1.0) * pixel_size, lod) * 0.24477;
-	color += textureLod(source_color, uv_interp + vec2(0.0, 2.0) * pixel_size, lod) * 0.06136;
-	color += textureLod(source_color, uv_interp + vec2(0.0, -1.0) * pixel_size, lod) * 0.24477;
-	color += textureLod(source_color, uv_interp + vec2(0.0, -2.0) * pixel_size, lod) * 0.06136;
-	frag_color = color;
+#ifdef GLOW_GAUSSIAN_VERTICAL
+	vec4 color = texture2DLod(source_color, uv_interp + vec2(0.0, 0.0) * pixel_size, lod) * 0.288713;
+	color += texture2DLod(source_color, uv_interp + vec2(0.0, 1.0) * pixel_size, lod) * 0.233062;
+	color += texture2DLod(source_color, uv_interp + vec2(0.0, 2.0) * pixel_size, lod) * 0.122581;
+	color += texture2DLod(source_color, uv_interp + vec2(0.0, -1.0) * pixel_size, lod) * 0.233062;
+	color += texture2DLod(source_color, uv_interp + vec2(0.0, -2.0) * pixel_size, lod) * 0.122581;
+	color *= glow_strength;
+	gl_FragColor = color;
 #endif
 
-	//glow uses larger sigma for a more rounded blur effect
+#ifndef USE_GLES_OVER_GL
+#if defined(DOF_FAR_BLUR) || defined(DOF_NEAR_BLUR)
 
-#ifdef GLOW_GAUSSIAN_HORIZONTAL
-	vec2 pix_size = pixel_size;
-	pix_size *= 0.5; //reading from larger buffer, so use more samples
-	vec4 color = textureLod(source_color, uv_interp + vec2(0.0, 0.0) * pix_size, lod) * 0.174938;
-	color += textureLod(source_color, uv_interp + vec2(1.0, 0.0) * pix_size, lod) * 0.165569;
-	color += textureLod(source_color, uv_interp + vec2(2.0, 0.0) * pix_size, lod) * 0.140367;
-	color += textureLod(source_color, uv_interp + vec2(3.0, 0.0) * pix_size, lod) * 0.106595;
-	color += textureLod(source_color, uv_interp + vec2(-1.0, 0.0) * pix_size, lod) * 0.165569;
-	color += textureLod(source_color, uv_interp + vec2(-2.0, 0.0) * pix_size, lod) * 0.140367;
-	color += textureLod(source_color, uv_interp + vec2(-3.0, 0.0) * pix_size, lod) * 0.106595;
-	color *= glow_strength;
-	frag_color = color;
+#ifdef DOF_QUALITY_LOW
+	const int dof_kernel_size = 5;
+	const int dof_kernel_from = 2;
+	float dof_kernel[5];
+	dof_kernel[0] = 0.153388;
+	dof_kernel[1] = 0.221461;
+	dof_kernel[2] = 0.250301;
+	dof_kernel[3] = 0.221461;
+	dof_kernel[4] = 0.153388;
 #endif
 
-#ifdef GLOW_GAUSSIAN_VERTICAL
-	vec4 color = textureLod(source_color, uv_interp + vec2(0.0, 0.0) * pixel_size, lod) * 0.288713;
-	color += textureLod(source_color, uv_interp + vec2(0.0, 1.0) * pixel_size, lod) * 0.233062;
-	color += textureLod(source_color, uv_interp + vec2(0.0, 2.0) * pixel_size, lod) * 0.122581;
-	color += textureLod(source_color, uv_interp + vec2(0.0, -1.0) * pixel_size, lod) * 0.233062;
-	color += textureLod(source_color, uv_interp + vec2(0.0, -2.0) * pixel_size, lod) * 0.122581;
-	color *= glow_strength;
-	frag_color = color;
+#ifdef DOF_QUALITY_MEDIUM
+	const int dof_kernel_size = 11;
+	const int dof_kernel_from = 5;
+	float dof_kernel[11];
+	dof_kernel[0] = 0.055037;
+	dof_kernel[1] = 0.072806;
+	dof_kernel[2] = 0.090506;
+	dof_kernel[3] = 0.105726;
+	dof_kernel[4] = 0.116061;
+	dof_kernel[5] = 0.119726;
+	dof_kernel[6] = 0.116061;
+	dof_kernel[7] = 0.105726;
+	dof_kernel[8] = 0.090506;
+	dof_kernel[9] = 0.072806;
+	dof_kernel[10] = 0.055037;
 #endif
 
+#ifdef DOF_QUALITY_HIGH
+	const int dof_kernel_size = 21;
+	const int dof_kernel_from = 10;
+	float dof_kernel[21];
+	dof_kernel[0] = 0.028174;
+	dof_kernel[1] = 0.032676;
+	dof_kernel[2] = 0.037311;
+	dof_kernel[3] = 0.041944;
+	dof_kernel[4] = 0.046421;
+	dof_kernel[5] = 0.050582;
+	dof_kernel[6] = 0.054261;
+	dof_kernel[7] = 0.057307;
+	dof_kernel[8] = 0.059587;
+	dof_kernel[9] = 0.060998;
+	dof_kernel[10] = 0.061476;
+	dof_kernel[11] = 0.060998;
+	dof_kernel[12] = 0.059587;
+	dof_kernel[13] = 0.057307;
+	dof_kernel[14] = 0.054261;
+	dof_kernel[15] = 0.050582;
+	dof_kernel[16] = 0.046421;
+	dof_kernel[17] = 0.041944;
+	dof_kernel[18] = 0.037311;
+	dof_kernel[19] = 0.032676;
+	dof_kernel[20] = 0.028174;
+#endif
+#endif
+#endif //!USE_GLES_OVER_GL
+
 #ifdef DOF_FAR_BLUR
 
 	vec4 color_accum = vec4(0.0);
 
-	float depth = textureLod(dof_source_depth, uv_interp, 0.0).r;
+	float depth = texture2DLod(dof_source_depth, uv_interp, 0.0).r;
 	depth = depth * 2.0 - 1.0;
 #ifdef USE_ORTHOGONAL_PROJECTION
 	depth = ((depth + (camera_z_far + camera_z_near) / (camera_z_far - camera_z_near)) * (camera_z_far - camera_z_near)) / 2.0;
@@ -184,17 +234,17 @@ void main() {
 
 		float tap_k = dof_kernel[i];
 
-		float tap_depth = texture(dof_source_depth, tap_uv, 0.0).r;
+		float tap_depth = texture2D(dof_source_depth, tap_uv, 0.0).r;
 		tap_depth = tap_depth * 2.0 - 1.0;
 #ifdef USE_ORTHOGONAL_PROJECTION
 		tap_depth = ((tap_depth + (camera_z_far + camera_z_near) / (camera_z_far - camera_z_near)) * (camera_z_far - camera_z_near)) / 2.0;
 #else
 		tap_depth = 2.0 * camera_z_near * camera_z_far / (camera_z_far + camera_z_near - tap_depth * (camera_z_far - camera_z_near));
 #endif
-		float tap_amount = mix(smoothstep(dof_begin, dof_end, tap_depth), 1.0, int_ofs == 0);
+		float tap_amount = int_ofs == 0 ? 1.0 : smoothstep(dof_begin, dof_end, tap_depth);
 		tap_amount *= tap_amount * tap_amount; //prevent undesired glow effect
 
-		vec4 tap_color = textureLod(source_color, tap_uv, 0.0) * tap_k;
+		vec4 tap_color = texture2DLod(source_color, tap_uv, 0.0) * tap_k;
 
 		k_accum += tap_k * tap_amount;
 		color_accum += tap_color * tap_amount;
@@ -204,7 +254,7 @@ void main() {
 		color_accum /= k_accum;
 	}
 
-	frag_color = color_accum; ///k_accum;
+	gl_FragColor = color_accum; ///k_accum;
 
 #endif
 
@@ -212,19 +262,19 @@ void main() {
 
 	vec4 color_accum = vec4(0.0);
 
-	float max_accum = 0;
+	float max_accum = 0.0;
 
 	for (int i = 0; i < dof_kernel_size; i++) {
 
 		int int_ofs = i - dof_kernel_from;
 		vec2 tap_uv = uv_interp + dof_dir * float(int_ofs) * dof_radius;
-		float ofs_influence = max(0.0, 1.0 - float(abs(int_ofs)) / float(dof_kernel_from));
+		float ofs_influence = max(0.0, 1.0 - abs(float(int_ofs)) / float(dof_kernel_from));
 
 		float tap_k = dof_kernel[i];
 
-		vec4 tap_color = textureLod(source_color, tap_uv, 0.0);
+		vec4 tap_color = texture2DLod(source_color, tap_uv, 0.0);
 
-		float tap_depth = texture(dof_source_depth, tap_uv, 0.0).r;
+		float tap_depth = texture2D(dof_source_depth, tap_uv, 0.0).r;
 		tap_depth = tap_depth * 2.0 - 1.0;
 #ifdef USE_ORTHOGONAL_PROJECTION
 		tap_depth = ((tap_depth + (camera_z_far + camera_z_near) / (camera_z_far - camera_z_near)) * (camera_z_far - camera_z_near)) / 2.0;
@@ -247,46 +297,16 @@ void main() {
 
 	color_accum.a = max(color_accum.a, sqrt(max_accum));
 
-#ifdef DOF_NEAR_BLUR_MERGE
-
-	vec4 original = textureLod(source_dof_original, uv_interp, 0.0);
-	color_accum = mix(original, color_accum, color_accum.a);
-
-#endif
-
-#ifndef DOF_NEAR_FIRST_TAP
-	//color_accum=vec4(vec3(color_accum.a),1.0);
-#endif
-	frag_color = color_accum;
+	gl_FragColor = color_accum;
 
 #endif
 
 #ifdef GLOW_FIRST_PASS
 
-#ifdef GLOW_USE_AUTO_EXPOSURE
-
-	frag_color /= texelFetch(source_auto_exposure, ivec2(0, 0), 0).r / auto_exposure_grey;
-#endif
-	frag_color *= exposure;
-
-	float luminance = max(frag_color.r, max(frag_color.g, frag_color.b));
+	float luminance = max(gl_FragColor.r, max(gl_FragColor.g, gl_FragColor.b));
 	float feedback = max(smoothstep(glow_hdr_threshold, glow_hdr_threshold + glow_hdr_scale, luminance), glow_bloom);
 
-	frag_color *= feedback;
-
-#endif
-
-#ifdef SIMPLE_COPY
-	vec4 color = textureLod(source_color, uv_interp, 0.0);
-	frag_color = color;
-#endif
-
-#ifdef SSAO_MERGE
-
-	vec4 color = textureLod(source_color, uv_interp, 0.0);
-	float ssao = textureLod(source_ssao, uv_interp, 0.0).r;
-
-	frag_color = vec4(mix(color.rgb, color.rgb * mix(ssao_color.rgb, vec3(1.0), ssao), color.a), 1.0);
+	gl_FragColor = min(gl_FragColor * feedback, vec4(luminance_cap));
 
 #endif
 }
diff --git a/drivers/gles2/shaders/lens_distorted.glsl b/drivers/gles2/shaders/lens_distorted.glsl
index 81898a75a5..f4ff80ba9a 100644
--- a/drivers/gles2/shaders/lens_distorted.glsl
+++ b/drivers/gles2/shaders/lens_distorted.glsl
@@ -34,8 +34,13 @@ void main() {
 #define mediump
 #define highp
 #else
-precision mediump float;
+#if defined(USE_HIGHP_PRECISION)
+precision highp float;
 precision highp int;
+#else
+precision mediump float;
+precision mediump int;
+#endif
 #endif
 
 uniform sampler2D source; //texunit:0
diff --git a/drivers/gles2/shaders/tonemap.glsl b/drivers/gles2/shaders/tonemap.glsl
index eae3b5a1ca..585d821626 100644
--- a/drivers/gles2/shaders/tonemap.glsl
+++ b/drivers/gles2/shaders/tonemap.glsl
@@ -1,66 +1,103 @@
 /* clang-format off */
 [vertex]
 
-layout(location = 0) in highp vec4 vertex_attrib;
+#ifdef USE_GLES_OVER_GL
+#define lowp
+#define mediump
+#define highp
+#else
+precision highp float;
+precision highp int;
+#endif
+
+attribute vec2 vertex_attrib; // attrib:0
 /* clang-format on */
-layout(location = 4) in vec2 uv_in;
+attribute vec2 uv_in; // attrib:4
 
-out vec2 uv_interp;
+varying vec2 uv_interp;
 
 void main() {
+	gl_Position = vec4(vertex_attrib, 0.0, 1.0);
 
-	gl_Position = vertex_attrib;
 	uv_interp = uv_in;
-#ifdef V_FLIP
-	uv_interp.y = 1.0 - uv_interp.y;
-#endif
 }
 
 /* clang-format off */
 [fragment]
 
-#if !defined(GLES_OVER_GL)
-precision mediump float;
+
+// texture2DLodEXT and textureCubeLodEXT are fragment shader specific.
+// Do not copy these defines in the vertex section.
+#ifndef USE_GLES_OVER_GL
+#ifdef GL_EXT_shader_texture_lod
+#extension GL_EXT_shader_texture_lod : enable
+#define texture2DLod(img, coord, lod) texture2DLodEXT(img, coord, lod)
+#define textureCubeLod(img, coord, lod) textureCubeLodEXT(img, coord, lod)
 #endif
+#endif // !USE_GLES_OVER_GL
 
-in vec2 uv_interp;
-/* clang-format on */
+#ifdef GL_ARB_shader_texture_lod
+#extension GL_ARB_shader_texture_lod : enable
+#endif
 
-uniform highp sampler2D source; //texunit:0
+#if !defined(GL_EXT_shader_texture_lod) && !defined(GL_ARB_shader_texture_lod)
+#define texture2DLod(img, coord, lod) texture2D(img, coord, lod)
+#define textureCubeLod(img, coord, lod) textureCube(img, coord, lod)
+#endif
 
-uniform float exposure;
-uniform float white;
+// Allows the use of bitshift operators for bicubic upscale
+#ifdef GL_EXT_gpu_shader4
+#extension GL_EXT_gpu_shader4 : enable
+#endif
 
-#ifdef USE_AUTO_EXPOSURE
+#ifdef USE_GLES_OVER_GL
+#define lowp
+#define mediump
+#define highp
+#else
+#if defined(USE_HIGHP_PRECISION)
+precision highp float;
+precision highp int;
+#else
+precision mediump float;
+precision mediump int;
+#endif
+#endif
 
-uniform highp sampler2D source_auto_exposure; //texunit:1
-uniform highp float auto_exposure_grey;
+#include "stdlib.glsl"
 
-#endif
+varying vec2 uv_interp;
+/* clang-format on */
 
-#if defined(USE_GLOW_LEVEL1) || defined(USE_GLOW_LEVEL2) || defined(USE_GLOW_LEVEL3) || defined(USE_GLOW_LEVEL4) || defined(USE_GLOW_LEVEL5) || defined(USE_GLOW_LEVEL6) || defined(USE_GLOW_LEVEL7)
+uniform highp sampler2D source; //texunit:0
 
-uniform highp sampler2D source_glow; //texunit:2
+#if defined(USE_GLOW_LEVEL1) || defined(USE_GLOW_LEVEL2) || defined(USE_GLOW_LEVEL3) || defined(USE_GLOW_LEVEL4) || defined(USE_GLOW_LEVEL5) || defined(USE_GLOW_LEVEL6) || defined(USE_GLOW_LEVEL7)
+#define USING_GLOW // only use glow when at least one glow level is selected
+
+#ifdef USE_MULTI_TEXTURE_GLOW
+uniform highp sampler2D source_glow1; //texunit:1
+uniform highp sampler2D source_glow2; //texunit:2
+uniform highp sampler2D source_glow3; //texunit:3
+uniform highp sampler2D source_glow4; //texunit:4
+uniform highp sampler2D source_glow5; //texunit:5
+uniform highp sampler2D source_glow6; //texunit:6
+uniform highp sampler2D source_glow7; //texunit:7
+#else
+uniform highp sampler2D source_glow; //texunit:1
+#endif
 uniform highp float glow_intensity;
-
 #endif
 
 #ifdef USE_BCS
-
 uniform vec3 bcs;
-
 #endif
 
 #ifdef USE_COLOR_CORRECTION
-
-uniform sampler2D color_correction; //texunit:3
-
+uniform sampler2D color_correction; //texunit:2
 #endif
 
-layout(location = 0) out vec4 frag_color;
-
+#ifdef GL_EXT_gpu_shader4
 #ifdef USE_GLOW_FILTER_BICUBIC
-
 // w0, w1, w2, and w3 are the four cubic B-spline basis functions
 float w0(float a) {
 	return (1.0 / 6.0) * (a * (a * (-a + 3.0) - 3.0) + 1.0);
@@ -101,8 +138,10 @@ uniform ivec2 glow_texture_size;
 vec4 texture2D_bicubic(sampler2D tex, vec2 uv, int p_lod) {
 	float lod = float(p_lod);
 	vec2 tex_size = vec2(glow_texture_size >> p_lod);
-	vec2 pixel_size = 1.0 / tex_size;
-	uv = uv * tex_size + 0.5;
+	vec2 pixel_size = vec2(1.0) / tex_size;
+
+	uv = uv * tex_size + vec2(0.5);
+
 	vec2 iuv = floor(uv);
 	vec2 fuv = fract(uv);
 
@@ -113,73 +152,97 @@ vec4 texture2D_bicubic(sampler2D tex, vec2 uv, int p_lod) {
 	float h0y = h0(fuv.y);
 	float h1y = h1(fuv.y);
 
-	vec2 p0 = (vec2(iuv.x + h0x, iuv.y + h0y) - 0.5) * pixel_size;
-	vec2 p1 = (vec2(iuv.x + h1x, iuv.y + h0y) - 0.5) * pixel_size;
-	vec2 p2 = (vec2(iuv.x + h0x, iuv.y + h1y) - 0.5) * pixel_size;
-	vec2 p3 = (vec2(iuv.x + h1x, iuv.y + h1y) - 0.5) * pixel_size;
+	vec2 p0 = (vec2(iuv.x + h0x, iuv.y + h0y) - vec2(0.5)) * pixel_size;
+	vec2 p1 = (vec2(iuv.x + h1x, iuv.y + h0y) - vec2(0.5)) * pixel_size;
+	vec2 p2 = (vec2(iuv.x + h0x, iuv.y + h1y) - vec2(0.5)) * pixel_size;
+	vec2 p3 = (vec2(iuv.x + h1x, iuv.y + h1y) - vec2(0.5)) * pixel_size;
 
-	return (g0(fuv.y) * (g0x * textureLod(tex, p0, lod) + g1x * textureLod(tex, p1, lod))) +
-		   (g1(fuv.y) * (g0x * textureLod(tex, p2, lod) + g1x * textureLod(tex, p3, lod)));
+	return (g0(fuv.y) * (g0x * texture2DLod(tex, p0, lod) + g1x * texture2DLod(tex, p1, lod))) +
+		   (g1(fuv.y) * (g0x * texture2DLod(tex, p2, lod) + g1x * texture2DLod(tex, p3, lod)));
 }
 
 #define GLOW_TEXTURE_SAMPLE(m_tex, m_uv, m_lod) texture2D_bicubic(m_tex, m_uv, m_lod)
+#else //!USE_GLOW_FILTER_BICUBIC
+#define GLOW_TEXTURE_SAMPLE(m_tex, m_uv, m_lod) texture2DLod(m_tex, m_uv, float(m_lod))
+#endif //USE_GLOW_FILTER_BICUBIC
 
-#else
+#else //!GL_EXT_gpu_shader4
+#define GLOW_TEXTURE_SAMPLE(m_tex, m_uv, m_lod) texture2DLod(m_tex, m_uv, float(m_lod))
+#endif //GL_EXT_gpu_shader4
 
-#define GLOW_TEXTURE_SAMPLE(m_tex, m_uv, m_lod) textureLod(m_tex, m_uv, float(m_lod))
+vec3 apply_glow(vec3 color, vec3 glow) { // apply glow using the selected blending mode
+#ifdef USE_GLOW_REPLACE
+	color = glow;
+#endif
 
+#ifdef USE_GLOW_SCREEN
+	color = max((color + glow) - (color * glow), vec3(0.0));
 #endif
 
-vec3 tonemap_filmic(vec3 color, float white) {
+#ifdef USE_GLOW_SOFTLIGHT
+	glow = glow * vec3(0.5) + vec3(0.5);
 
-	float A = 0.15;
-	float B = 0.50;
-	float C = 0.10;
-	float D = 0.20;
-	float E = 0.02;
-	float F = 0.30;
-	float W = 11.2;
+	color.r = (glow.r <= 0.5) ? (color.r - (1.0 - 2.0 * glow.r) * color.r * (1.0 - color.r)) : (((glow.r > 0.5) && (color.r <= 0.25)) ? (color.r + (2.0 * glow.r - 1.0) * (4.0 * color.r * (4.0 * color.r + 1.0) * (color.r - 1.0) + 7.0 * color.r)) : (color.r + (2.0 * glow.r - 1.0) * (sqrt(color.r) - color.r)));
+	color.g = (glow.g <= 0.5) ? (color.g - (1.0 - 2.0 * glow.g) * color.g * (1.0 - color.g)) : (((glow.g > 0.5) && (color.g <= 0.25)) ? (color.g + (2.0 * glow.g - 1.0) * (4.0 * color.g * (4.0 * color.g + 1.0) * (color.g - 1.0) + 7.0 * color.g)) : (color.g + (2.0 * glow.g - 1.0) * (sqrt(color.g) - color.g)));
+	color.b = (glow.b <= 0.5) ? (color.b - (1.0 - 2.0 * glow.b) * color.b * (1.0 - color.b)) : (((glow.b > 0.5) && (color.b <= 0.25)) ? (color.b + (2.0 * glow.b - 1.0) * (4.0 * color.b * (4.0 * color.b + 1.0) * (color.b - 1.0) + 7.0 * color.b)) : (color.b + (2.0 * glow.b - 1.0) * (sqrt(color.b) - color.b)));
+#endif
 
-	vec3 coltn = ((color * (A * color + C * B) + D * E) / (color * (A * color + B) + D * F)) - E / F;
-	float whitetn = ((white * (A * white + C * B) + D * E) / (white * (A * white + B) + D * F)) - E / F;
+#if !defined(USE_GLOW_SCREEN) && !defined(USE_GLOW_SOFTLIGHT) && !defined(USE_GLOW_REPLACE) // no other selected -> additive
+	color += glow;
+#endif
 
-	return coltn / whitetn;
+	return color;
 }
 
-vec3 tonemap_aces(vec3 color) {
-	float a = 2.51f;
-	float b = 0.03f;
-	float c = 2.43f;
-	float d = 0.59f;
-	float e = 0.14f;
-	return color = clamp((color * (a * color + b)) / (color * (c * color + d) + e), vec3(0.0), vec3(1.0));
+vec3 apply_bcs(vec3 color, vec3 bcs) {
+	color = mix(vec3(0.0), color, bcs.x);
+	color = mix(vec3(0.5), color, bcs.y);
+	color = mix(vec3(dot(vec3(1.0), color) * 0.33333), color, bcs.z);
+
+	return color;
 }
 
-vec3 tonemap_reindhart(vec3 color, float white) {
+vec3 apply_color_correction(vec3 color, sampler2D correction_tex) {
+	color.r = texture2D(correction_tex, vec2(color.r, 0.0)).r;
+	color.g = texture2D(correction_tex, vec2(color.g, 0.0)).g;
+	color.b = texture2D(correction_tex, vec2(color.b, 0.0)).b;
 
-	return (color * (1.0 + (color / (white)))) / (1.0 + color);
+	return color;
 }
 
 void main() {
+	vec3 color = texture2DLod(source, uv_interp, 0.0).rgb;
 
-	vec4 color = textureLod(source, uv_interp, 0.0);
+	// Glow
 
-#ifdef USE_AUTO_EXPOSURE
-
-	color /= texelFetch(source_auto_exposure, ivec2(0, 0), 0).r / auto_exposure_grey;
+#ifdef USING_GLOW
+	vec3 glow = vec3(0.0);
+#ifdef USE_MULTI_TEXTURE_GLOW
+#ifdef USE_GLOW_LEVEL1
+	glow += GLOW_TEXTURE_SAMPLE(source_glow1, uv_interp, 0).rgb;
+#ifdef USE_GLOW_LEVEL2
+	glow += GLOW_TEXTURE_SAMPLE(source_glow2, uv_interp, 0).rgb;
+#ifdef USE_GLOW_LEVEL3
+	glow += GLOW_TEXTURE_SAMPLE(source_glow3, uv_interp, 0).rgb;
+#ifdef USE_GLOW_LEVEL4
+	glow += GLOW_TEXTURE_SAMPLE(source_glow4, uv_interp, 0).rgb;
+#ifdef USE_GLOW_LEVEL5
+	glow += GLOW_TEXTURE_SAMPLE(source_glow5, uv_interp, 0).rgb;
+#ifdef USE_GLOW_LEVEL6
+	glow += GLOW_TEXTURE_SAMPLE(source_glow6, uv_interp, 0).rgb;
+#ifdef USE_GLOW_LEVEL7
+	glow += GLOW_TEXTURE_SAMPLE(source_glow7, uv_interp, 0).rgb;
+#endif
+#endif
+#endif
+#endif
+#endif
 #endif
-
-	color *= exposure;
-
-#if defined(USE_GLOW_LEVEL1) || defined(USE_GLOW_LEVEL2) || defined(USE_GLOW_LEVEL3) || defined(USE_GLOW_LEVEL4) || defined(USE_GLOW_LEVEL5) || defined(USE_GLOW_LEVEL6) || defined(USE_GLOW_LEVEL7)
-#define USING_GLOW
 #endif
 
-#if defined(USING_GLOW)
-	vec3 glow = vec3(0.0);
+#else
 
 #ifdef USE_GLOW_LEVEL1
-
 	glow += GLOW_TEXTURE_SAMPLE(source_glow, uv_interp, 1).rgb;
 #endif
 
@@ -206,100 +269,21 @@ void main() {
 #ifdef USE_GLOW_LEVEL7
 	glow += GLOW_TEXTURE_SAMPLE(source_glow, uv_interp, 7).rgb;
 #endif
+#endif //USE_MULTI_TEXTURE_GLOW
 
 	glow *= glow_intensity;
-
-#endif
-
-#ifdef USE_REINDHART_TONEMAPPER
-
-	color.rgb = tonemap_reindhart(color.rgb, white);
-
-#if defined(USING_GLOW)
-	glow = tonemap_reindhart(glow, white);
-#endif
-
+	color = apply_glow(color, glow);
 #endif
 
-#ifdef USE_FILMIC_TONEMAPPER
-
-	color.rgb = tonemap_filmic(color.rgb, white);
-
-#if defined(USING_GLOW)
-	glow = tonemap_filmic(glow, white);
-#endif
-
-#endif
-
-#ifdef USE_ACES_TONEMAPPER
-
-	color.rgb = tonemap_aces(color.rgb);
-
-#if defined(USING_GLOW)
-	glow = tonemap_aces(glow);
-#endif
-
-#endif
-
-	//regular Linear -> SRGB conversion
-	vec3 a = vec3(0.055);
-	color.rgb = mix((vec3(1.0) + a) * pow(color.rgb, vec3(1.0 / 2.4)) - a, 12.92 * color.rgb, lessThan(color.rgb, vec3(0.0031308)));
-
-#if defined(USING_GLOW)
-	glow = mix((vec3(1.0) + a) * pow(glow, vec3(1.0 / 2.4)) - a, 12.92 * glow, lessThan(glow, vec3(0.0031308)));
-#endif
-
-	//glow needs to be added in SRGB space (together with image space effects)
-
-	color.rgb = clamp(color.rgb, 0.0, 1.0);
-
-#if defined(USING_GLOW)
-	glow = clamp(glow, 0.0, 1.0);
-#endif
-
-#ifdef USE_GLOW_REPLACE
-
-	color.rgb = glow;
-
-#endif
-
-#ifdef USE_GLOW_SCREEN
-
-	color.rgb = max((color.rgb + glow) - (color.rgb * glow), vec3(0.0));
-
-#endif
-
-#ifdef USE_GLOW_SOFTLIGHT
-
-	{
-
-		glow = (glow * 0.5) + 0.5;
-		color.r = (glow.r <= 0.5) ? (color.r - (1.0 - 2.0 * glow.r) * color.r * (1.0 - color.r)) : (((glow.r > 0.5) && (color.r <= 0.25)) ? (color.r + (2.0 * glow.r - 1.0) * (4.0 * color.r * (4.0 * color.r + 1.0) * (color.r - 1.0) + 7.0 * color.r)) : (color.r + (2.0 * glow.r - 1.0) * (sqrt(color.r) - color.r)));
-		color.g = (glow.g <= 0.5) ? (color.g - (1.0 - 2.0 * glow.g) * color.g * (1.0 - color.g)) : (((glow.g > 0.5) && (color.g <= 0.25)) ? (color.g + (2.0 * glow.g - 1.0) * (4.0 * color.g * (4.0 * color.g + 1.0) * (color.g - 1.0) + 7.0 * color.g)) : (color.g + (2.0 * glow.g - 1.0) * (sqrt(color.g) - color.g)));
-		color.b = (glow.b <= 0.5) ? (color.b - (1.0 - 2.0 * glow.b) * color.b * (1.0 - color.b)) : (((glow.b > 0.5) && (color.b <= 0.25)) ? (color.b + (2.0 * glow.b - 1.0) * (4.0 * color.b * (4.0 * color.b + 1.0) * (color.b - 1.0) + 7.0 * color.b)) : (color.b + (2.0 * glow.b - 1.0) * (sqrt(color.b) - color.b)));
-	}
-
-#endif
-
-#if defined(USING_GLOW) && !defined(USE_GLOW_SCREEN) && !defined(USE_GLOW_SOFTLIGHT) && !defined(USE_GLOW_REPLACE)
-	//additive
-	color.rgb += glow;
-#endif
+	// Additional effects
 
 #ifdef USE_BCS
-
-	color.rgb = mix(vec3(0.0), color.rgb, bcs.x);
-	color.rgb = mix(vec3(0.5), color.rgb, bcs.y);
-	color.rgb = mix(vec3(dot(vec3(1.0), color.rgb) * 0.33333), color.rgb, bcs.z);
-
+	color = apply_bcs(color, bcs);
 #endif
 
 #ifdef USE_COLOR_CORRECTION
-
-	color.r = texture(color_correction, vec2(color.r, 0.0)).r;
-	color.g = texture(color_correction, vec2(color.g, 0.0)).g;
-	color.b = texture(color_correction, vec2(color.b, 0.0)).b;
+	color = apply_color_correction(color, color_correction);
 #endif
 
-	frag_color = vec4(color.rgb, 1.0);
+	gl_FragColor = vec4(color, 1.0);
 }