LibSoftGPU: Use bitwise and instead of modulus operator for POT textures

Where possible the sampler will wrap texture coordinates using a bitwise
and instead of a modulus. This speeds up the calculation quite a bit.

3 files changed, 46 insertions, 6 deletions

diff --git a/Userland/Libraries/LibSoftGPU/Image.cpp b/Userland/Libraries/LibSoftGPU/Image.cpp
index 972073dfe4..34ad239f59 100644
--- a/Userland/Libraries/LibSoftGPU/Image.cpp
+++ b/Userland/Libraries/LibSoftGPU/Image.cpp
@@ -21,6 +21,15 @@ Image::Image(ImageFormat format, unsigned width, unsigned height, unsigned depth
     VERIFY(levels > 0);
     VERIFY(layers > 0);
 
+    if ((width & (width - 1)) == 0)
+        m_width_is_power_of_two = true;
+
+    if ((height & (height - 1)) == 0)
+        m_height_is_power_of_two = true;
+
+    if ((depth & (depth - 1)) == 0)
+        m_depth_is_power_of_two = true;
+
     m_mipmap_sizes.append({ width, height, depth });
     m_mipmap_offsets.append(0);
 
diff --git a/Userland/Libraries/LibSoftGPU/Image.h b/Userland/Libraries/LibSoftGPU/Image.h
index 0edc0ce9de..884e5d59c7 100644
--- a/Userland/Libraries/LibSoftGPU/Image.h
+++ b/Userland/Libraries/LibSoftGPU/Image.h
@@ -28,6 +28,9 @@ public:
     unsigned level_depth(unsigned level) const { return m_mipmap_sizes[level].z(); }
     unsigned num_levels() const { return m_num_levels; }
     unsigned num_layers() const { return m_num_layers; }
+    bool width_is_power_of_two() const { return m_width_is_power_of_two; }
+    bool height_is_power_of_two() const { return m_height_is_power_of_two; }
+    bool depth_is_power_of_two() const { return m_depth_is_power_of_two; }
 
     FloatVector4 texel(unsigned layer, unsigned level, unsigned x, unsigned y, unsigned z) const
     {
@@ -68,6 +71,9 @@ private:
     Vector<size_t, 16> m_mipmap_offsets;
     Vector<Vector3<unsigned>, 16> m_mipmap_sizes;
     Vector<u8> m_data;
+    bool m_width_is_power_of_two { false };
+    bool m_height_is_power_of_two { false };
+    bool m_depth_is_power_of_two { false };
 };
 
 }
diff --git a/Userland/Libraries/LibSoftGPU/Sampler.cpp b/Userland/Libraries/LibSoftGPU/Sampler.cpp
index 973a7e9f0a..c713016181 100644
--- a/Userland/Libraries/LibSoftGPU/Sampler.cpp
+++ b/Userland/Libraries/LibSoftGPU/Sampler.cpp
@@ -128,6 +128,9 @@ Vector4<AK::SIMD::f32x4> Sampler::sample_2d(Vector2<AK::SIMD::f32x4> const& uv)
         image.level_height(level[3]),
     };
 
+    u32x4 width_mask = width - 1;
+    u32x4 height_mask = height - 1;
+
     f32x4 s = wrap(uv.x(), m_config.texture_wrap_u, width);
     f32x4 t = wrap(uv.y(), m_config.texture_wrap_v, height);
 
@@ -135,21 +138,43 @@ Vector4<AK::SIMD::f32x4> Sampler::sample_2d(Vector2<AK::SIMD::f32x4> const& uv)
     f32x4 v = t * to_f32x4(height);
 
     if (m_config.texture_mag_filter == TextureFilter::Nearest) {
-        u32x4 i = to_i32x4(u) % width;
-        u32x4 j = to_i32x4(v) % height;
+        u32x4 i = to_u32x4(u);
+        u32x4 j = to_u32x4(v);
         u32x4 k = expand4(0u);
 
+        i = image.width_is_power_of_two() ? i & width_mask : i % width;
+        j = image.height_is_power_of_two() ? j & height_mask : j % height;
+
         return texel4(image, layer, level, i, j, k);
     }
 
     u -= 0.5f;
     v -= 0.5f;
 
-    i32x4 i0 = m_config.texture_wrap_u == TextureWrapMode::Repeat ? to_i32x4(to_u32x4(floor_int_range(u)) % width) : to_i32x4(floor_int_range(u));
-    i32x4 j0 = m_config.texture_wrap_v == TextureWrapMode::Repeat ? to_i32x4(to_u32x4(floor_int_range(v)) % height) : to_i32x4(floor_int_range(v));
+    i32x4 i0 = to_i32x4(floor_int_range(u));
+    i32x4 i1 = i0 + 1;
+    i32x4 j0 = to_i32x4(floor_int_range(v));
+    i32x4 j1 = j0 + 1;
+
+    if (m_config.texture_wrap_u == TextureWrapMode::Repeat) {
+        if (image.width_is_power_of_two()) {
+            i0 = (i32x4)(i0 & width_mask);
+            i1 = (i32x4)(i1 & width_mask);
+        } else {
+            i0 = (i32x4)(i0 % width);
+            i1 = (i32x4)(i1 % width);
+        }
+    }
 
-    i32x4 i1 = m_config.texture_wrap_u == TextureWrapMode::Repeat ? to_i32x4((i0 + 1) % width) : i0 + 1;
-    i32x4 j1 = m_config.texture_wrap_v == TextureWrapMode::Repeat ? to_i32x4((j0 + 1) % height) : j0 + 1;
+    if (m_config.texture_wrap_v == TextureWrapMode::Repeat) {
+        if (image.height_is_power_of_two()) {
+            j0 = (i32x4)(j0 & height_mask);
+            j1 = (i32x4)(j1 & height_mask);
+        } else {
+            j0 = (i32x4)(j0 % height);
+            j1 = (i32x4)(j1 % height);
+        }
+    }
 
     u32x4 k = expand4(0u);