merge from sebastian-frysztak/i3lock-color fast-blur to begin cleanup

bless you

Makefile

@@ -14,6 +14,7 @@ endif
 CFLAGS += -std=c99
 CFLAGS += -pipe
 CFLAGS += -Wall
+CFLAGS += -mssse3
 CFLAGS += -O2
 CPPFLAGS += -D_GNU_SOURCE
 CPPFLAGS += -DXKBCOMPOSE=$(shell if test -e /usr/include/xkbcommon/xkbcommon-compose.h ; then echo 1 ; else echo 0 ; fi )

blur.c

@@ -22,9 +22,7 @@
  */
 
 #include <math.h>
-#include <stdint.h>
-#include <stdio.h>
-#include <cairo.h>
+#include "blur.h"
 
 #define ARRAY_LENGTH(a) (sizeof (a) / sizeof (a)[0])
 
@@ -35,13 +33,7 @@ blur_image_surface (cairo_surface_t *surface, int radius)
     cairo_surface_t *tmp;
     int width, height;
     int src_stride, dst_stride;
-    int x, y, z, w;
-    uint8_t *src, *dst;
-    uint32_t *s, *d, a, p;
-    int i, j, k;
-    uint8_t kernel[17];
-    const int size = ARRAY_LENGTH (kernel);
-    const int half = size / 2;
+    uint32_t *src, *dst;
 
     if (cairo_surface_status (surface))
     return;
@@ -71,12 +63,33 @@ blur_image_surface (cairo_surface_t *surface, int radius)
     if (cairo_surface_status (tmp))
     return;
 
-    src = cairo_image_surface_get_data (surface);
+    src = (uint32_t*)cairo_image_surface_get_data (surface);
     src_stride = cairo_image_surface_get_stride (surface);
 
-    dst = cairo_image_surface_get_data (tmp);
+    dst = (uint32_t*)cairo_image_surface_get_data (tmp);
     dst_stride = cairo_image_surface_get_stride (tmp);
 
+    //blur_impl_naive(src, dst, width, height, src_stride, dst_stride, 10000);
+    //blur_impl_sse2(src, dst, width, height, 4.5);
+    blur_impl_ssse3(src, dst, width, height, 4.5);
+
+    cairo_surface_destroy (tmp);
+    cairo_surface_flush (surface);
+    cairo_surface_mark_dirty (surface);
+}
+
+void blur_impl_naive(uint32_t* _src, uint32_t* _dst, int width, int height, int src_stride, int dst_stride, int radius)
+{
+    int x, y, z, w;
+    uint32_t *s, *d, a, p;
+    int i, j, k;
+    uint8_t kernel[17];
+    const int size = ARRAY_LENGTH (kernel);
+    const int half = size / 2;
+
+    uint8_t *src = (uint8_t*)_src;
+    uint8_t *dst = (uint8_t*)_dst;
+
     a = 0;
     for (i = 0; i < size; i++) {
     double f = i - half;
@@ -135,9 +148,5 @@ blur_image_surface (cairo_surface_t *surface, int radius)
         d[j] = (x / a << 24) | (y / a << 16) | (z / a << 8) | w / a;
     }
     }
-
-    cairo_surface_destroy (tmp);
-    cairo_surface_flush (surface);
-    cairo_surface_mark_dirty (surface);
 }
 

blur.h

@@ -1,7 +1,15 @@
 #ifndef _BLUR_H
 #define _BLUR_H
 
+#include <stdint.h>
+#include <cairo.h>
+
 void blur_image_surface (cairo_surface_t *surface, int radius);
+void blur_impl_naive(uint32_t* src, uint32_t* dst, int width, int height, int src_stride, int dst_stride, int radius);
+void blur_impl_sse2(uint32_t* src, uint32_t* dst, int width, int height, float sigma);
+void blur_impl_horizontal_pass_sse2(uint32_t *src, uint32_t *dst, float *kernel, int width, int height);
+void blur_impl_ssse3(uint32_t* src, uint32_t* dst, int width, int height, float sigma);
+void blur_impl_horizontal_pass_ssse3(uint32_t *src, uint32_t *dst, int8_t *kernel, int width, int height);
 
 #endif
 

blur_simd.c

@@ -0,0 +1,250 @@
+/*
+ * vim:ts=4:sw=4:expandtab
+ *
+ * © 2016 Sebastian Frysztak 
+ *
+ * See LICENSE for licensing information
+ *
+ */
+
+#include "blur.h"
+#include <math.h>
+#include <xmmintrin.h>
+#include <tmmintrin.h>
+
+#define ALIGN16 __attribute__((aligned(16)))
+#define KERNEL_SIZE 15 
+#define HALF_KERNEL KERNEL_SIZE / 2
+
+// number of xmm registers needed to store 
+// input pixels for given kernel size
+#define REGISTERS_CNT (KERNEL_SIZE + 4/2) / 4
+
+// scaling factor for kernel coefficients.
+// higher values cause desaturation.
+// used in SSSE3 implementation.
+#define SCALE_FACTOR 7
+
+void blur_impl_sse2(uint32_t *src, uint32_t *dst, int width, int height, float sigma) {
+    // prepare kernel
+    float kernel[KERNEL_SIZE];
+    float coeff = 1.0 / sqrtf(2 * M_PI * sigma * sigma), sum = 0;
+
+    for (int i = 0; i < KERNEL_SIZE; i++) {
+        float x = HALF_KERNEL - i;
+        kernel[i] = coeff * expf(-x * x / (2.0 * sigma * sigma));
+        sum += kernel[i];
+    }
+
+    // normalize kernel
+    for (int i = 0; i < KERNEL_SIZE; i++)
+        kernel[i] /= sum;
+
+    // horizontal pass includes image transposition:
+    // instead of writing pixel src[x] to dst[x],
+    // we write it to transposed location.
+    // (to be exact: dst[height * current_column + current_row])
+    blur_impl_horizontal_pass_sse2(src, dst, kernel, width, height);
+    blur_impl_horizontal_pass_sse2(dst, src, kernel, height, width);
+}
+
+void blur_impl_horizontal_pass_sse2(uint32_t *src, uint32_t *dst, float *kernel, int width, int height) {
+    for (int row = 0; row < height; row++) {
+        for (int column = 0; column < width; column++, src++) {
+            __m128i rgbaIn[REGISTERS_CNT];
+
+            // handle borders
+            int leftBorder = column < HALF_KERNEL;
+            int rightBorder = column > width - HALF_KERNEL;
+            if (leftBorder || rightBorder) {
+                uint32_t _rgbaIn[KERNEL_SIZE] ALIGN16;
+                int i = 0;
+                if (leftBorder) {
+                    // for kernel size 7x7 and column == 0, we have:
+                    // x x x P0 P1 P2 P3
+                    // first loop mirrors P{0..3} to fill x's,
+                    // second one loads P{0..3}
+                    for (; i < HALF_KERNEL - column; i++)
+                        _rgbaIn[i] = *(src + (HALF_KERNEL - i));
+                    for (; i < KERNEL_SIZE; i++)
+                        _rgbaIn[i] = *(src - (HALF_KERNEL - i));
+                } else {
+                    for (; i < width - column; i++)
+                        _rgbaIn[i] = *(src + i);
+                    for (int k = 0; i < KERNEL_SIZE; i++, k++)
+                        _rgbaIn[i] = *(src - k);
+                }
+
+                for (int k = 0; k < REGISTERS_CNT; k++)
+                    rgbaIn[k] = _mm_load_si128((__m128i*)(_rgbaIn + 4*k));
+            } else {
+                for (int k = 0; k < REGISTERS_CNT; k++)
+                    rgbaIn[k] = _mm_loadu_si128((__m128i*)(src + 4*k - HALF_KERNEL));
+            }
+
+            // unpack each pixel, convert to float,
+            // multiply by corresponding kernel value
+            // and add to accumulator
+            __m128i tmp;
+            __m128i zero = _mm_setzero_si128();
+            __m128 rgba_ps;
+            __m128 acc = _mm_setzero_ps();
+            int counter = 0;
+
+            for (int i = 0; i < 3; i++)
+            {
+                tmp = _mm_unpacklo_epi8(rgbaIn[i], zero);
+                rgba_ps = _mm_cvtepi32_ps(_mm_unpacklo_epi16(tmp, zero));
+                acc = _mm_add_ps(acc, _mm_mul_ps(rgba_ps, _mm_set1_ps(kernel[counter++])));
+                rgba_ps = _mm_cvtepi32_ps(_mm_unpackhi_epi16(tmp, zero));
+                acc = _mm_add_ps(acc, _mm_mul_ps(rgba_ps, _mm_set1_ps(kernel[counter++])));
+
+                tmp = _mm_unpackhi_epi8(rgbaIn[i], zero);
+                rgba_ps = _mm_cvtepi32_ps(_mm_unpacklo_epi16(tmp, zero));
+                acc = _mm_add_ps(acc, _mm_mul_ps(rgba_ps, _mm_set1_ps(kernel[counter++])));
+                rgba_ps = _mm_cvtepi32_ps(_mm_unpackhi_epi16(tmp, zero));
+                acc = _mm_add_ps(acc, _mm_mul_ps(rgba_ps, _mm_set1_ps(kernel[counter++])));
+            }
+
+            tmp = _mm_unpacklo_epi8(rgbaIn[3], zero);
+            rgba_ps = _mm_cvtepi32_ps(_mm_unpacklo_epi16(tmp, zero));
+            acc = _mm_add_ps(acc, _mm_mul_ps(rgba_ps, _mm_set1_ps(kernel[counter++])));
+            rgba_ps = _mm_cvtepi32_ps(_mm_unpackhi_epi16(tmp, zero));
+            acc = _mm_add_ps(acc, _mm_mul_ps(rgba_ps, _mm_set1_ps(kernel[counter++])));
+
+            tmp = _mm_unpackhi_epi8(rgbaIn[3], zero);
+            rgba_ps = _mm_cvtepi32_ps(_mm_unpacklo_epi16(tmp, zero));
+            acc = _mm_add_ps(acc, _mm_mul_ps(rgba_ps, _mm_set1_ps(kernel[counter++])));
+
+            __m128i rgbaOut = _mm_cvtps_epi32(acc);
+            rgbaOut = _mm_packs_epi32(rgbaOut, zero);
+            rgbaOut = _mm_packus_epi16(rgbaOut, zero);
+            *(dst + height * column + row) = _mm_cvtsi128_si32(rgbaOut);
+        }
+    }
+}
+
+void blur_impl_ssse3(uint32_t *src, uint32_t *dst, int width, int height, float sigma) {
+    // prepare kernel
+    float kernelf[KERNEL_SIZE];
+    int8_t kernel[KERNEL_SIZE + 1];
+    float coeff = 1.0 / sqrtf(2 * M_PI * sigma * sigma), sum = 0;
+
+    for (int i = 0; i < KERNEL_SIZE; i++) {
+        float x = HALF_KERNEL - i;
+        kernelf[i] = coeff * expf(-x * x / (2.0 * sigma * sigma));
+        sum += kernelf[i];
+    }
+
+    // normalize kernel
+    for (int i = 0; i < KERNEL_SIZE; i++)
+        kernelf[i] /= sum;
+
+    // round to nearest integer and convert to int
+    for (int i = 0; i < KERNEL_SIZE; i++)
+        kernel[i] = (int8_t)rintf(kernelf[i] * (1 << SCALE_FACTOR));
+    kernel[KERNEL_SIZE] = 0;
+
+    // horizontal pass includes image transposition:
+    // instead of writing pixel src[x] to dst[x],
+    // we write it to transposed location.
+    // (to be exact: dst[height * current_column + current_row])
+    blur_impl_horizontal_pass_ssse3(src, dst, kernel, width, height);
+    blur_impl_horizontal_pass_ssse3(dst, src, kernel, height, width);
+}
+
+
+void blur_impl_horizontal_pass_ssse3(uint32_t *src, uint32_t *dst, int8_t *kernel, int width, int height) {
+    __m128i _kern = _mm_loadu_si128((__m128i*)kernel);
+    __m128i rgbaIn[REGISTERS_CNT];
+
+    for (int row = 0; row < height; row++) {
+        for (int column = 0; column < width; column++, src++) {
+            uint32_t _rgbaIn[KERNEL_SIZE] ALIGN16;
+            // handle borders
+            int leftBorder = column < HALF_KERNEL;
+            int rightBorder = column > width - HALF_KERNEL;
+            if (leftBorder || rightBorder) {
+                int i = 0;
+                if (leftBorder) {
+                    // for kernel size 7x7 and column == 0, we have:
+                    // x x x P0 P1 P2 P3
+                    // first loop mirrors P{0..3} to fill x's,
+                    // second one loads P{0..3}
+                    for (; i < HALF_KERNEL - column; i++)
+                        _rgbaIn[i] = *(src + (HALF_KERNEL - i));
+                    for (; i < KERNEL_SIZE; i++)
+                        _rgbaIn[i] = *(src - (HALF_KERNEL - i));
+                } else {
+                    for (; i < width - column; i++)
+                        _rgbaIn[i] = *(src + i);
+                    for (int k = 0; i < KERNEL_SIZE; i++, k++)
+                        _rgbaIn[i] = *(src - k);
+                }
+
+                for (int k = 0; k < REGISTERS_CNT; k++)
+                    rgbaIn[k] = _mm_load_si128((__m128i*)(_rgbaIn + 4*k));
+            } else {
+                for (int k = 0; k < REGISTERS_CNT; k++)
+                    rgbaIn[k] = _mm_loadu_si128((__m128i*)(src + 4*k - HALF_KERNEL));
+            }
+
+            // basis of this implementation is _mm_maddubs_epi16 (aka pmaddubsw).
+            // 'rgba' holds 16 unsigned bytes, so 4 pixels.
+            // 'kern' holds 16 signed bytes kernel values multiplied by (1 << SCALE_FACTOR).
+            // before multiplication takes place, vectors need to be prepared:
+            // 'rgba' is shuffled from R1B1G1A1...R4B4G4A4 to R1R2R3R4...A1A2A3A4
+            // 'kern' is shuffled from w1w2w3w4...w13w14w15w16 to w1w2w3w4 repeated 4 times
+            // then we call _mm_maddubs_epi16 and we get:
+            // --------------------------------------------------------------------------------------
+            // | R1*w1 + R2*w2 | R3*w3 + R4*w4 | G1*w1 + G2*w2 | G3*w3 + G4*w4 | repeat for B and A |
+            // --------------------------------------------------------------------------------------
+            // each 'rectangle' is a 16-byte signed int.
+            // then we repeat the process for the rest of input pixels,
+            // call _mm_hadds_epi16 to add adjacent ints and shift right to scale by SCALE_FACTOR.
+
+            __m128i rgba, kern;
+            __m128i zero = _mm_setzero_si128();
+            __m128i acc = _mm_setzero_si128();
+
+            const __m128i rgba_shuf_mask = _mm_setr_epi8(0, 4, 8,  12,
+                                                         1, 5, 9,  13,
+                                                         2, 6, 10, 14,
+                                                         3, 7, 11, 15);
+
+            const __m128i kern_shuf_mask = _mm_setr_epi8(0, 1, 2, 3,
+                                                         0, 1, 2, 3,
+                                                         0, 1, 2, 3,
+                                                         0, 1, 2, 3);
+
+            rgba = _mm_shuffle_epi8(rgbaIn[0], rgba_shuf_mask);
+            kern = _mm_shuffle_epi8(_kern, kern_shuf_mask);
+            acc = _mm_adds_epi16(acc, _mm_maddubs_epi16(rgba, kern));
+
+            rgba = _mm_shuffle_epi8(rgbaIn[1], rgba_shuf_mask);
+            kern = _mm_shuffle_epi8(_mm_srli_si128(_kern, 4), kern_shuf_mask);
+            acc = _mm_adds_epi16(acc, _mm_maddubs_epi16(rgba, kern));
+
+            rgba = _mm_shuffle_epi8(rgbaIn[2], rgba_shuf_mask);
+            kern = _mm_shuffle_epi8(_mm_srli_si128(_kern, 8), kern_shuf_mask);
+            acc = _mm_adds_epi16(acc, _mm_maddubs_epi16(rgba, kern));
+
+            rgba = _mm_shuffle_epi8(rgbaIn[3], rgba_shuf_mask);
+            kern = _mm_shuffle_epi8(_mm_srli_si128(_kern, 12), kern_shuf_mask);
+            acc = _mm_adds_epi16(acc, _mm_maddubs_epi16(rgba, kern));
+
+            acc = _mm_hadds_epi16(acc, zero);
+            acc = _mm_srai_epi16(acc, SCALE_FACTOR);
+
+            // Cairo sets alpha channel to 255
+            // (or -1, depending how you look at it)
+            // this quickly overflows accumulator,
+            // and alpha is calculated completely wrong.
+            // I assume most people don't use semi-transparent
+            // lock screen images, so no one will mind if we
+            // 'correct it' by setting alpha to 255.
+            *(dst + height * column + row) =
+                _mm_cvtsi128_si32(_mm_packus_epi16(acc, zero)) | 0xFF000000;
+        }
+    }
+}