diff options
Diffstat (limited to 'ui/surface/accelerated_surface_transformer_win.hlsl')
| -rw-r--r-- | ui/surface/accelerated_surface_transformer_win.hlsl | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/ui/surface/accelerated_surface_transformer_win.hlsl b/ui/surface/accelerated_surface_transformer_win.hlsl index 0bd6fda..aa105ce 100644 --- a/ui/surface/accelerated_surface_transformer_win.hlsl +++ b/ui/surface/accelerated_surface_transformer_win.hlsl @@ -13,10 +13,17 @@ struct Vertex { 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; }; @@ -26,3 +33,268 @@ Vertex vsOneTexture(Vertex input) { 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); +} |