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/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
Texture2D InputTexture : register(t0);
SamplerState InputSampler : register(s0);
Texture2D GradientTexture : register(t1);
SamplerState GradientSampler : register(s1);
cbuffer radialGradientConstants : register(b0)
{
// Precalculate as much as we can!
float3 diff : packoffset(c0.x);
float2 center1 : packoffset(c1.x);
float A : packoffset(c1.z);
float radius1 : packoffset(c1.w);
float sq_radius1 : packoffset(c2.x);
// The next two values are used for a hack to compensate for an apparent
// bug in D2D where the GradientSampler SamplerState doesn't get the
// correct addressing modes.
float repeat_correct : packoffset(c2.y);
float allow_odd : packoffset(c2.z);
float3x2 transform : packoffset(c3.x);
}
cbuffer conicGradientConstants : register(b0)
{
float2 center : packoffset(c0.x);
float angle : packoffset(c0.z);
float start_offset : packoffset(c0.w);
float end_offset : packoffset(c1.x);
// The next two values are used for a hack to compensate for an apparent
// bug in D2D where the GradientSampler SamplerState doesn't get the
// correct addressing modes.
float repeat_correct_conic : packoffset(c1.y);
float allow_odd_conic : packoffset(c1.z);
float3x2 transform_conic : packoffset(c2.x);
}
static const float M_PI = 3.14159265f;
float4 SampleConicGradientPS(
float4 clipSpaceOutput : SV_POSITION,
float4 sceneSpaceOutput : SCENE_POSITION,
float4 texelSpaceInput0 : TEXCOORD0
) : SV_Target
{
float2 p = float2(sceneSpaceOutput.x * transform_conic._11 + sceneSpaceOutput.y * transform_conic._21 + transform_conic._31,
sceneSpaceOutput.x * transform_conic._12 + sceneSpaceOutput.y * transform_conic._22 + transform_conic._32);
float2 dir = float2(
-(center.y - p.y),
(center.x - p.x));
float vstart = start_offset;
float vend = end_offset;
float n = 1/(vend-vstart);
float current_angle = atan2(dir.y, dir.x)-angle;
float lambda = fmod(n*current_angle/M_PI/2+vend-vstart+.5,1);
float offset = lambda;
float4 output = GradientTexture.Sample(GradientSampler, float2(offset, 0.5));
// Premultiply
output.rgb *= output.a;
// Multiply the output color by the input mask for the operation.
output *= InputTexture.Sample(InputSampler, texelSpaceInput0.xy);
return output;
};
float4 SampleRadialGradientPS(
float4 clipSpaceOutput : SV_POSITION,
float4 sceneSpaceOutput : SCENE_POSITION,
float4 texelSpaceInput0 : TEXCOORD0
) : SV_Target
{
// Radial gradient painting is defined as the set of circles whose centers
// are described by C(t) = (C2 - C1) * t + C1; with radii
// R(t) = (R2 - R1) * t + R1; for R(t) > 0. This shader solves the
// quadratic equation that arises when calculating t for pixel (x, y).
//
// A more extensive derrivation can be found in the pixman radial gradient
// code.
float2 p = float2(sceneSpaceOutput.x * transform._11 + sceneSpaceOutput.y * transform._21 + transform._31,
sceneSpaceOutput.x * transform._12 + sceneSpaceOutput.y * transform._22 + transform._32);
float3 dp = float3(p - center1, radius1);
// dpx * dcx + dpy * dcy + r * dr
float B = dot(dp, diff);
float C = pow(dp.x, 2) + pow(dp.y, 2) - sq_radius1;
float det = pow(B, 2) - A * C;
float sqrt_det = sqrt(abs(det));
float2 t = (B + float2(sqrt_det, -sqrt_det)) / A;
float2 isValid = step(float2(-radius1, -radius1), t * diff.z);
float upper_t = lerp(t.y, t.x, isValid.x);
// Addressing mode bug work-around.. first let's see if we should consider odd repetitions separately.
float oddeven = abs(fmod(floor(upper_t), 2)) * allow_odd;
// Now let's calculate even or odd addressing in a branchless manner.
float upper_t_repeated = ((upper_t - floor(upper_t)) * (1.0f - oddeven)) + ((ceil(upper_t) - upper_t) * oddeven);
float4 output = GradientTexture.Sample(GradientSampler, float2(upper_t * (1.0f - repeat_correct) + upper_t_repeated * repeat_correct, 0.5));
// Premultiply
output.rgb *= output.a;
// Multiply the output color by the input mask for the operation.
output *= InputTexture.Sample(InputSampler, texelSpaceInput0.xy);
// In order to compile for PS_4_0_level_9_3 we need to be branchless.
// This is essentially returning nothing, i.e. bailing early if:
// det < 0 || max(isValid.x, isValid.y) <= 0
return output * abs(step(max(isValid.x, isValid.y), 0) - 1.0f) * step(0, det);
};
float4 SampleRadialGradientA0PS(
float4 clipSpaceOutput : SV_POSITION,
float4 sceneSpaceOutput : SCENE_POSITION,
float4 texelSpaceInput0 : TEXCOORD0
) : SV_Target
{
// This simpler shader is used for the degenerate case where A is 0,
// i.e. we're actually solving a linear equation.
float2 p = float2(sceneSpaceOutput.x * transform._11 + sceneSpaceOutput.y * transform._21 + transform._31,
sceneSpaceOutput.x * transform._12 + sceneSpaceOutput.y * transform._22 + transform._32);
float3 dp = float3(p - center1, radius1);
// dpx * dcx + dpy * dcy + r * dr
float B = dot(dp, diff);
float C = pow(dp.x, 2) + pow(dp.y, 2) - pow(radius1, 2);
float t = 0.5 * C / B;
// Addressing mode bug work-around.. first let's see if we should consider odd repetitions separately.
float oddeven = abs(fmod(floor(t), 2)) * allow_odd;
// Now let's calculate even or odd addressing in a branchless manner.
float t_repeated = ((t - floor(t)) * (1.0f - oddeven)) + ((ceil(t) - t) * oddeven);
float4 output = GradientTexture.Sample(GradientSampler, float2(t * (1.0f - repeat_correct) + t_repeated * repeat_correct, 0.5));
// Premultiply
output.rgb *= output.a;
// Multiply the output color by the input mask for the operation.
output *= InputTexture.Sample(InputSampler, texelSpaceInput0.xy);
// In order to compile for PS_4_0_level_9_3 we need to be branchless.
// This is essentially returning nothing, i.e. bailing early if:
// -radius1 >= t * diff.z
return output * abs(step(t * diff.z, -radius1) - 1.0f);
};