1 files changed, 26 insertions, 0 deletions
diff --git a/source/blender/gpu/shaders/compositor/compositor_tone_map_simple.glsl b/source/blender/gpu/shaders/compositor/compositor_tone_map_simple.glsl
new file mode 100644
index 00000000000..ce42d021dd1
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+++ b/source/blender/gpu/shaders/compositor/compositor_tone_map_simple.glsl
@@ -0,0 +1,26 @@
+#pragma BLENDER_REQUIRE(gpu_shader_compositor_texture_utilities.glsl)
+#pragma BLENDER_REQUIRE(gpu_shader_common_math_utils.glsl)
+
+/* Tone mapping based on equation (3) from Reinhard, Erik, et al. "Photographic tone reproduction
+ * for digital images." Proceedings of the 29th annual conference on Computer graphics and
+ * interactive techniques. 2002. */
+void main()
+{
+  ivec2 texel = ivec2(gl_GlobalInvocationID.xy);
+
+  vec4 input_color = texture_load(input_tx, texel);
+
+  /* Equation (2) from Reinhard's 2002 paper. */
+  vec4 scaled_color = input_color * luminance_scale;
+
+  /* Equation (3) from Reinhard's 2002 paper, but with the 1 replaced with the blend factor for
+   * more flexibility. See ToneMapOperation::compute_luminance_scale_blend_factor. */
+  vec4 denominator = luminance_scale_blend_factor + scaled_color;
+  vec4 tone_mapped_color = safe_divide(scaled_color, denominator);
+
+  if (inverse_gamma != 0.0) {
+    tone_mapped_color = pow(max(tone_mapped_color, vec4(0.0)), vec4(inverse_gamma));
+  }
+
+  imageStore(output_img, texel, vec4(tone_mapped_color.rgb, input_color.a));
+}