gfx/2d/ShadersD2D1.hlsl@6474c204b198 (annotated)
gfx/2d/ShadersD2D1.hlsl
Wed, 31 Dec 2014 06:09:35 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 06:09:35 +0100
- changeset 0
- 6474c204b198
- permissions
- -rw-r--r--
Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.
| michael@0 | 1 | /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- |
| michael@0 | 2 | * This Source Code Form is subject to the terms of the Mozilla Public |
| michael@0 | 3 | * License, v. 2.0. If a copy of the MPL was not distributed with this |
| michael@0 | 4 | * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| michael@0 | 5 | |
| michael@0 | 6 | Texture2D InputTexture : register(t0); |
| michael@0 | 7 | SamplerState InputSampler : register(s0); |
| michael@0 | 8 | Texture2D GradientTexture : register(t1); |
| michael@0 | 9 | SamplerState GradientSampler : register(s1); |
| michael@0 | 10 | |
| michael@0 | 11 | cbuffer constants : register(b0) |
| michael@0 | 12 | { |
| michael@0 | 13 | // Precalculate as much as we can! |
| michael@0 | 14 | float3 diff : packoffset(c0.x); |
| michael@0 | 15 | float2 center1 : packoffset(c1.x); |
| michael@0 | 16 | float A : packoffset(c1.z); |
| michael@0 | 17 | float radius1 : packoffset(c1.w); |
| michael@0 | 18 | float sq_radius1 : packoffset(c2.x); |
| michael@0 | 19 | float3x2 transform : packoffset(c3.x); |
| michael@0 | 20 | } |
| michael@0 | 21 | |
| michael@0 | 22 | float4 SampleRadialGradientPS( |
| michael@0 | 23 | float4 clipSpaceOutput : SV_POSITION, |
| michael@0 | 24 | float4 sceneSpaceOutput : SCENE_POSITION, |
| michael@0 | 25 | float4 texelSpaceInput0 : TEXCOORD0 |
| michael@0 | 26 | ) : SV_Target |
| michael@0 | 27 | { |
| michael@0 | 28 | // Radial gradient painting is defined as the set of circles whose centers |
| michael@0 | 29 | // are described by C(t) = (C2 - C1) * t + C1; with radii |
| michael@0 | 30 | // R(t) = (R2 - R1) * t + R1; for R(t) > 0. This shader solves the |
| michael@0 | 31 | // quadratic equation that arises when calculating t for pixel (x, y). |
| michael@0 | 32 | // |
| michael@0 | 33 | // A more extensive derrivation can be found in the pixman radial gradient |
| michael@0 | 34 | // code. |
| michael@0 | 35 | |
| michael@0 | 36 | float2 p = float2(sceneSpaceOutput.x * transform._11 + sceneSpaceOutput.y * transform._21 + transform._31, |
| michael@0 | 37 | sceneSpaceOutput.x * transform._12 + sceneSpaceOutput.y * transform._22 + transform._32); |
| michael@0 | 38 | float3 dp = float3(p - center1, radius1); |
| michael@0 | 39 | |
| michael@0 | 40 | // dpx * dcx + dpy * dcy + r * dr |
| michael@0 | 41 | float B = dot(dp, diff); |
| michael@0 | 42 | |
| michael@0 | 43 | float C = pow(dp.x, 2) + pow(dp.y, 2) - sq_radius1; |
| michael@0 | 44 | |
| michael@0 | 45 | float det = pow(B, 2) - A * C; |
| michael@0 | 46 | |
| michael@0 | 47 | float sqrt_det = sqrt(abs(det)); |
| michael@0 | 48 | |
| michael@0 | 49 | float2 t = (B + float2(sqrt_det, -sqrt_det)) / A; |
| michael@0 | 50 | |
| michael@0 | 51 | float2 isValid = step(float2(-radius1, -radius1), t * diff.z); |
| michael@0 | 52 | |
| michael@0 | 53 | float upper_t = lerp(t.y, t.x, isValid.x); |
| michael@0 | 54 | |
| michael@0 | 55 | float4 output = GradientTexture.Sample(GradientSampler, float2(upper_t, 0.5)); |
| michael@0 | 56 | // Premultiply |
| michael@0 | 57 | output.rgb *= output.a; |
| michael@0 | 58 | // Multiply the output color by the input mask for the operation. |
| michael@0 | 59 | output *= InputTexture.Sample(InputSampler, texelSpaceInput0.xy); |
| michael@0 | 60 | |
| michael@0 | 61 | // In order to compile for PS_4_0_level_9_3 we need to be branchless. |
| michael@0 | 62 | // This is essentially returning nothing, i.e. bailing early if: |
| michael@0 | 63 | // det < 0 || max(isValid.x, isValid.y) <= 0 |
| michael@0 | 64 | return output * abs(step(max(isValid.x, isValid.y), 0) - 1.0f) * step(0, det); |
| michael@0 | 65 | }; |
| michael@0 | 66 | |
| michael@0 | 67 | float4 SampleRadialGradientA0PS( |
| michael@0 | 68 | float4 clipSpaceOutput : SV_POSITION, |
| michael@0 | 69 | float4 sceneSpaceOutput : SCENE_POSITION, |
| michael@0 | 70 | float4 texelSpaceInput0 : TEXCOORD0 |
| michael@0 | 71 | ) : SV_Target |
| michael@0 | 72 | { |
| michael@0 | 73 | // This simpler shader is used for the degenerate case where A is 0, |
| michael@0 | 74 | // i.e. we're actually solving a linear equation. |
| michael@0 | 75 | |
| michael@0 | 76 | float2 p = float2(sceneSpaceOutput.x * transform._11 + sceneSpaceOutput.y * transform._21 + transform._31, |
| michael@0 | 77 | sceneSpaceOutput.x * transform._12 + sceneSpaceOutput.y * transform._22 + transform._32); |
| michael@0 | 78 | float3 dp = float3(p - center1, radius1); |
| michael@0 | 79 | |
| michael@0 | 80 | // dpx * dcx + dpy * dcy + r * dr |
| michael@0 | 81 | float B = dot(dp, diff); |
| michael@0 | 82 | |
| michael@0 | 83 | float C = pow(dp.x, 2) + pow(dp.y, 2) - pow(radius1, 2); |
| michael@0 | 84 | |
| michael@0 | 85 | float t = 0.5 * C / B; |
| michael@0 | 86 | |
| michael@0 | 87 | float4 output = GradientTexture.Sample(GradientSampler, float2(t, 0.5)); |
| michael@0 | 88 | // Premultiply |
| michael@0 | 89 | output.rgb *= output.a; |
| michael@0 | 90 | // Multiply the output color by the input mask for the operation. |
| michael@0 | 91 | output *= InputTexture.Sample(InputSampler, texelSpaceInput0.xy); |
| michael@0 | 92 | |
| michael@0 | 93 | // In order to compile for PS_4_0_level_9_3 we need to be branchless. |
| michael@0 | 94 | // This is essentially returning nothing, i.e. bailing early if: |
| michael@0 | 95 | // -radius1 >= t * diff.z |
| michael@0 | 96 | return output * abs(step(t * diff.z, -radius1) - 1.0f); |
| michael@0 | 97 | }; |
