diff options
Diffstat (limited to 'source/blender/gpu/shaders/common/gpu_shader_common_curves.glsl')
| -rw-r--r-- | source/blender/gpu/shaders/common/gpu_shader_common_curves.glsl | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/source/blender/gpu/shaders/common/gpu_shader_common_curves.glsl b/source/blender/gpu/shaders/common/gpu_shader_common_curves.glsl new file mode 100644 index 00000000000..8948ed77557 --- /dev/null +++ b/source/blender/gpu/shaders/common/gpu_shader_common_curves.glsl @@ -0,0 +1,162 @@ +vec4 white_balance(vec4 color, vec4 black_level, vec4 white_level) +{ + vec4 range = max(white_level - black_level, vec4(1e-5f)); + return (color - black_level) / range; +} + +float extrapolate_if_needed(float parameter, float value, float start_slope, float end_slope) +{ + if (parameter < 0.0) { + return value + parameter * start_slope; + } + + if (parameter > 1.0) { + return value + (parameter - 1.0) * end_slope; + } + + return value; +} + +/* Same as extrapolate_if_needed but vectorized. */ +vec3 extrapolate_if_needed(vec3 parameters, vec3 values, vec3 start_slopes, vec3 end_slopes) +{ + vec3 end_or_zero_slopes = mix(vec3(0.0), end_slopes, greaterThan(parameters, vec3(1.0))); + vec3 slopes = mix(end_or_zero_slopes, start_slopes, lessThan(parameters, vec3(0.0))); + parameters = parameters - mix(vec3(0.0), vec3(1.0), greaterThan(parameters, vec3(1.0))); + return values + parameters * slopes; +} + +/* Curve maps are stored in sampler objects that are evaluated in the [0, 1] range, so normalize + * parameters accordingly. */ +#define NORMALIZE_PARAMETER(parameter, minimum, range) ((parameter - minimum) * range) + +void curves_combined_rgb(float factor, + vec4 color, + vec4 black_level, + vec4 white_level, + sampler1DArray curve_map, + const float layer, + vec4 range_minimums, + vec4 range_dividers, + vec4 start_slopes, + vec4 end_slopes, + out vec4 result) +{ + vec4 balanced = white_balance(color, black_level, white_level); + + /* First, evaluate alpha curve map at all channels. The alpha curve is the Combined curve in the + * UI. */ + vec3 parameters = NORMALIZE_PARAMETER(balanced.rgb, range_minimums.aaa, range_dividers.aaa); + result.r = texture(curve_map, vec2(parameters.x, layer)).a; + result.g = texture(curve_map, vec2(parameters.y, layer)).a; + result.b = texture(curve_map, vec2(parameters.z, layer)).a; + + /* Then, extrapolate if needed. */ + result.rgb = extrapolate_if_needed(parameters, result.rgb, start_slopes.aaa, end_slopes.aaa); + + /* Then, evaluate each channel on its curve map. */ + parameters = NORMALIZE_PARAMETER(result.rgb, range_minimums.rgb, range_dividers.rgb); + result.r = texture(curve_map, vec2(parameters.r, layer)).r; + result.g = texture(curve_map, vec2(parameters.g, layer)).g; + result.b = texture(curve_map, vec2(parameters.b, layer)).b; + + /* Then, extrapolate again if needed. */ + result.rgb = extrapolate_if_needed(parameters, result.rgb, start_slopes.rgb, end_slopes.rgb); + result.a = color.a; + + result = mix(color, result, factor); +} + +void curves_combined_only(float factor, + vec4 color, + vec4 black_level, + vec4 white_level, + sampler1DArray curve_map, + const float layer, + float range_minimum, + float range_divider, + float start_slope, + float end_slope, + out vec4 result) +{ + vec4 balanced = white_balance(color, black_level, white_level); + + /* Evaluate alpha curve map at all channels. The alpha curve is the Combined curve in the + * UI. */ + vec3 parameters = NORMALIZE_PARAMETER(balanced.rgb, range_minimum, range_divider); + result.r = texture(curve_map, vec2(parameters.x, layer)).a; + result.g = texture(curve_map, vec2(parameters.y, layer)).a; + result.b = texture(curve_map, vec2(parameters.z, layer)).a; + + /* Then, extrapolate if needed. */ + result.rgb = extrapolate_if_needed(parameters, result.rgb, vec3(start_slope), vec3(end_slope)); + result.a = color.a; + + result = mix(color, result, factor); +} + +void curves_vector(vec3 vector, + sampler1DArray curve_map, + const float layer, + vec3 range_minimums, + vec3 range_dividers, + vec3 start_slopes, + vec3 end_slopes, + out vec3 result) +{ + /* Evaluate each component on its curve map. */ + vec3 parameters = NORMALIZE_PARAMETER(vector, range_minimums, range_dividers); + result.x = texture(curve_map, vec2(parameters.x, layer)).x; + result.y = texture(curve_map, vec2(parameters.y, layer)).y; + result.z = texture(curve_map, vec2(parameters.z, layer)).z; + + /* Then, extrapolate if needed. */ + result = extrapolate_if_needed(parameters, result, start_slopes, end_slopes); +} + +void curves_vector_mixed(float factor, + vec3 vector, + sampler1DArray curve_map, + const float layer, + vec3 range_minimums, + vec3 range_dividers, + vec3 start_slopes, + vec3 end_slopes, + out vec3 result) +{ + curves_vector( + vector, curve_map, layer, range_minimums, range_dividers, start_slopes, end_slopes, result); + result = mix(vector, result, factor); +} + +void curves_float(float value, + sampler1DArray curve_map, + const float layer, + float range_minimum, + float range_divider, + float start_slope, + float end_slope, + out float result) +{ + /* Evaluate the normalized value on the first curve map. */ + float parameter = NORMALIZE_PARAMETER(value, range_minimum, range_divider); + result = texture(curve_map, vec2(parameter, layer)).x; + + /* Then, extrapolate if needed. */ + result = extrapolate_if_needed(parameter, result, start_slope, end_slope); +} + +void curves_float_mixed(float factor, + float value, + sampler1DArray curve_map, + const float layer, + float range_minimum, + float range_divider, + float start_slope, + float end_slope, + out float result) +{ + curves_float( + value, curve_map, layer, range_minimum, range_divider, start_slope, end_slope, result); + result = mix(value, result, factor); +} |