// Copyright (c) 2012 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. // @gyp_namespace(ui_surface) // Compiles into C++ as 'accelerated_surface_transformer_win_hlsl_compiled.h' struct Vertex { float4 position : POSITION; float2 texCoord : TEXCOORD0; }; texture t; sampler s; extern uniform float2 kRenderTargetSize : c0; extern uniform float2 kTextureScale : c1; // @gyp_compile(vs_2_0, vsOneTexture) // // Passes a position and texture coordinate to the pixel shader. Vertex vsOneTexture(Vertex input) { // Texture scale is typically just 1 (to do nothing) or -1 (to flip). input.texCoord = ((2 * (input.texCoord - 0.5) * kTextureScale) + 1) / 2; input.position.x += -1 / kRenderTargetSize.x; input.position.y += 1 / kRenderTargetSize.y; return input; }; // @gyp_compile(ps_2_0, psOneTexture) // // Samples a texture at the given texture coordinate and returns the result. float4 psOneTexture(float2 texCoord : TEXCOORD0) : COLOR0 { return tex2D(s, texCoord); }; // Return |value| rounded up to the nearest multiple of |multiple|. float alignTo(float value, float multiple) { // |multiple| is usually a compile-time constant; this check allows // the compiler to avoid the fmod when possible. if (multiple == 1) return value; // Biasing the value provides numeric stability. We expect |value| to // be an integer; this prevents 4.001 from being rounded up to 8. float biased_value = value - 0.5; return biased_value + multiple - fmod(biased_value, multiple); } float4 packForByteOrder(float4 value) { return value.bgra; } // Adjust the input vertex to address the correct range of texels. This depends // on the value of the shader constant |kRenderTargetSize|, as well as an // alignment factor |align| that effectively specifies the footprint of the // texel samples done by this shader pass, and is used to correct when that // footprint size doesn't align perfectly with the actual input size. Vertex adjustForAlignmentAndPacking(Vertex vtx, float2 align) { float src_width = kRenderTargetSize.x; float src_height = kRenderTargetSize.y; // Because our caller expects to be sampling |align.x| many pixels from src at // a time, if src's width isn't evenly divisible by |align.x|, it is necessary // to pretend that the source is slightly bigger than it is. float bloated_src_width = alignTo(src_width, align.x); float bloated_src_height = alignTo(src_height, align.y); // When bloated_src_width != src_width, we'll adjust the texture coordinates // to sample past the edge of the vtx; clamping will produce extra copies of // the last row. float texture_x_scale = bloated_src_width / src_width; float texture_y_scale = bloated_src_height / src_height; // Adjust positions so that we're addressing full fragments in the output, per // the top-left filling convention. The shifts would be equivalent to // 1/dst_width and 1/dst_height, if we were to calculate those explicitly. vtx.position.x -= align.x / bloated_src_width; vtx.position.y += align.y / bloated_src_height; // Apply the texture scale vtx.texCoord.x *= texture_x_scale; vtx.texCoord.y *= texture_y_scale; return vtx; } /////////////////////////////////////////////////////////////////////// // RGB24 to YV12 in two passes; writing two 8888 targets each pass. // // YV12 is full-resolution luma and half-resolution blue/red chroma. // // (original) // XRGB XRGB XRGB XRGB XRGB XRGB XRGB XRGB // XRGB XRGB XRGB XRGB XRGB XRGB XRGB XRGB // XRGB XRGB XRGB XRGB XRGB XRGB XRGB XRGB // XRGB XRGB XRGB XRGB XRGB XRGB XRGB XRGB // XRGB XRGB XRGB XRGB XRGB XRGB XRGB XRGB // XRGB XRGB XRGB XRGB XRGB XRGB XRGB XRGB // | // | (y plane) (temporary) // | YYYY YYYY UVUV UVUV // +--> { YYYY YYYY + UVUV UVUV } // YYYY YYYY UVUV UVUV // First YYYY YYYY UVUV UVUV // pass YYYY YYYY UVUV UVUV // YYYY YYYY UVUV UVUV // | // | (u plane) (v plane) // Second | UUUU VVVV // pass +--> { UUUU + VVVV } // UUUU VVVV // /////////////////////////////////////////////////////////////////////// // Phase one of RGB24->YV12 conversion: vsFetch4Pixels/psConvertRGBtoY8UV44 // // @gyp_compile(vs_2_0, vsFetch4Pixels) // @gyp_compile(ps_2_0, psConvertRGBtoY8UV44) // // Writes four source pixels at a time to a full-size Y plane and a half-width // interleaved UV plane. After execution, the Y plane is complete but the UV // planes still need to be de-interleaved and vertically scaled. // void vsFetch4Pixels(in Vertex vertex, out float4 position : POSITION, out float2 texCoord0 : TEXCOORD0, out float2 texCoord1 : TEXCOORD1, out float2 texCoord2 : TEXCOORD2, out float2 texCoord3 : TEXCOORD3) { Vertex adjusted = adjustForAlignmentAndPacking(vertex, float2(4, 1)); // Set up four taps, aligned to texel centers if the src's true size is // |kRenderTargetSize|, and doing bilinear interpolation otherwise. float2 one_texel_x = float2(1 / kRenderTargetSize.x, 0); position = adjusted.position; texCoord0 = adjusted.texCoord - 1.5f * one_texel_x; texCoord1 = adjusted.texCoord - 0.5f * one_texel_x; texCoord2 = adjusted.texCoord + 0.5f * one_texel_x; texCoord3 = adjusted.texCoord + 1.5f * one_texel_x; }; struct YV16QuadPixel { float4 YYYY : COLOR0; float4 UUVV : COLOR1; }; // Color conversion constants. static const float3x1 rgb_to_y = float3x1( +0.257f, +0.504f, +0.098f ); static const float3x1 rgb_to_u = float3x1( -0.148f, -0.291f, +0.439f ); static const float3x1 rgb_to_v = float3x1( +0.439f, -0.368f, -0.071f ); static const float y_bias = 0.0625f; static const float uv_bias = 0.5f; YV16QuadPixel psConvertRGBtoY8UV44(float2 texCoord0 : TEXCOORD0, float2 texCoord1 : TEXCOORD1, float2 texCoord2 : TEXCOORD2, float2 texCoord3 : TEXCOORD3) { // Load the four texture samples into a matrix. float4x3 rgb_quad_pixel = float4x3(tex2D(s, texCoord0).rgb, tex2D(s, texCoord1).rgb, tex2D(s, texCoord2).rgb, tex2D(s, texCoord3).rgb); // RGB -> Y conversion (x4). float4 yyyy = mul(rgb_quad_pixel, rgb_to_y) + y_bias; // Average adjacent texture samples while converting RGB->UV. This is the same // as color converting then averaging, but slightly less math. These values // will be in the range [-0.439f, +0.439f] and still need to have the bias // term applied. float2x3 rgb_double_pixel = float2x3(rgb_quad_pixel[0] + rgb_quad_pixel[1], rgb_quad_pixel[2] + rgb_quad_pixel[3]); float2 uu = mul(rgb_double_pixel, rgb_to_u / 2); float2 vv = mul(rgb_double_pixel, rgb_to_v / 2); // Package the result to account for BGRA byte ordering. YV16QuadPixel result; result.YYYY = packForByteOrder(yyyy); result.UUVV.xyzw = float4(uu, vv) + uv_bias; // Apply uv bias. return result; }; // Phase two of RGB24->YV12 conversion: vsFetch2Pixels/psConvertUV44toU2V2 // // @gyp_compile(vs_2_0, vsFetch2Pixels) // @gyp_compile(ps_2_0, psConvertUV44toU2V2) // // Deals with UV only. Input is interleaved UV pixels, already scaled // horizontally, packed two per RGBA texel. Output is two color planes U and V, // packed four to a RGBA pixel. // // Vertical scaling happens via a half-texel offset and bilinear interpolation // during texture sampling. void vsFetch2Pixels(in Vertex vertex, out float4 position : POSITION, out float2 texCoord0 : TEXCOORD0, out float2 texCoord1 : TEXCOORD1) { // We fetch two texels in the horizontal direction, and scale by 2 in the // vertical direction. Vertex adjusted = adjustForAlignmentAndPacking(vertex, float2(2, 2)); // Setup the two texture coordinates. No need to adjust texCoord.y; it's // already at the mid-way point between the two rows. Horizontally, we'll // fetch two texels so that we have enough data to fill our output. float2 one_texel_x = float2(1 / kRenderTargetSize.x, 0); position = adjusted.position; texCoord0 = adjusted.texCoord - 0.5f * one_texel_x; texCoord1 = adjusted.texCoord + 0.5f * one_texel_x; }; struct UV8QuadPixel { float4 UUUU : COLOR0; float4 VVVV : COLOR1; }; UV8QuadPixel psConvertUV44toU2V2(float2 texCoord0 : TEXCOORD0, float2 texCoord1 : TEXCOORD1) { // We're just sampling two pixels and unswizzling them. There's no need to do // vertical scaling with math, since bilinear interpolation in the sampler // takes care of that. float4 lo_uuvv = tex2D(s, texCoord0); float4 hi_uuvv = tex2D(s, texCoord1); UV8QuadPixel result; result.UUUU = packForByteOrder(float4(lo_uuvv.xy, hi_uuvv.xy)); result.VVVV = packForByteOrder(float4(lo_uuvv.zw, hi_uuvv.zw)); return result; }; /////////////////////////////////////////////////////////////////////// // RGB24 to YV12 in three passes, without MRT: one pass per output color plane. // vsFetch4Pixels is the common vertex shader for all three passes. // // Note that this technique will not do full bilinear filtering on its RGB // input (you'd get correctly filtered Y, but aliasing in U and V). // // Pass 1: vsFetch4Pixels + psConvertRGBToY // Pass 2: vsFetch4Pixels_Scale2 + psConvertRGBToU // Pass 3: vsFetch4Pixels_Scale2 + psConvertRGBToV // // @gyp_compile(vs_2_0, vsFetch4Pixels_Scale2) // @gyp_compile(ps_2_0, psConvertRGBtoY) // @gyp_compile(ps_2_0, psConvertRGBtoU) // @gyp_compile(ps_2_0, psConvertRGBtoV) // /////////////////////////////////////////////////////////////////////// void vsFetch4Pixels_Scale2(in Vertex vertex, out float4 position : POSITION, out float2 texCoord0 : TEXCOORD0, out float2 texCoord1 : TEXCOORD1, out float2 texCoord2 : TEXCOORD2, out float2 texCoord3 : TEXCOORD3) { Vertex adjusted = adjustForAlignmentAndPacking(vertex, float2(8, 2)); // Set up four taps, each of which samples a 2x2 texel quad at the midpoint. float2 one_texel_x = float2(1 / kRenderTargetSize.x, 0); position = adjusted.position; texCoord0 = adjusted.texCoord - 3 * one_texel_x; texCoord1 = adjusted.texCoord - 1 * one_texel_x; texCoord2 = adjusted.texCoord + 1 * one_texel_x; texCoord3 = adjusted.texCoord + 3 * one_texel_x; }; // RGB -> Y, four samples at a time. float4 psConvertRGBtoY(float2 texCoord0 : TEXCOORD0, float2 texCoord1 : TEXCOORD1, float2 texCoord2 : TEXCOORD2, float2 texCoord3 : TEXCOORD3) : COLOR0 { float4x3 rgb_quad_pixel = float4x3(tex2D(s, texCoord0).rgb, tex2D(s, texCoord1).rgb, tex2D(s, texCoord2).rgb, tex2D(s, texCoord3).rgb); return packForByteOrder(mul(rgb_quad_pixel, rgb_to_y) + y_bias); } // RGB -> U, four samples at a time. float4 psConvertRGBtoU(float2 texCoord0 : TEXCOORD0, float2 texCoord1 : TEXCOORD1, float2 texCoord2 : TEXCOORD2, float2 texCoord3 : TEXCOORD3) : COLOR0 { float4x3 rgb_quad_pixel = float4x3(tex2D(s, texCoord0).rgb, tex2D(s, texCoord1).rgb, tex2D(s, texCoord2).rgb, tex2D(s, texCoord3).rgb); return packForByteOrder(mul(rgb_quad_pixel, rgb_to_u) + uv_bias); } // RGB -> V, four samples at a time. float4 psConvertRGBtoV(float2 texCoord0 : TEXCOORD0, float2 texCoord1 : TEXCOORD1, float2 texCoord2 : TEXCOORD2, float2 texCoord3 : TEXCOORD3) : COLOR0 { float4x3 rgb_quad_pixel = float4x3(tex2D(s, texCoord0).rgb, tex2D(s, texCoord1).rgb, tex2D(s, texCoord2).rgb, tex2D(s, texCoord3).rgb); return packForByteOrder(mul(rgb_quad_pixel, rgb_to_v) + uv_bias); }