X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=resample_effect.cpp;h=30c40c4145fdd73903a7ce485d8ca75f7b28c783;hp=9b6d5f3d4d964168d0a4a0f191e8552b1f54217d;hb=425d68dcbdd681ad3157000360521e8f36eb6c4c;hpb=b1b5194238dd8b357148a3eee48d8d3a1ad04b35

diff --git a/resample_effect.cpp b/resample_effect.cpp
index 9b6d5f3..30c40c4 100644
--- a/resample_effect.cpp
+++ b/resample_effect.cpp
@@ -1,7 +1,7 @@
 // Three-lobed Lanczos, the most common choice.
 // Note that if you change this, the accuracy for LANCZOS_TABLE_SIZE
 // needs to be recomputed.
-#define LANCZOS_RADIUS 3.0
+#define LANCZOS_RADIUS 3.0f
 
 #include <epoxy/gl.h>
 #include <assert.h>
@@ -90,7 +90,7 @@ float lanczos_weight_cached(float x)
 		return 0.0f;
 	}
 	float table_pos = x * (LANCZOS_TABLE_SIZE / LANCZOS_RADIUS);
-	int table_pos_int = int(table_pos);  // Truncate towards zero.
+	unsigned table_pos_int = int(table_pos);  // Truncate towards zero.
 	float table_pos_frac = table_pos - table_pos_int;
 	assert(table_pos < LANCZOS_TABLE_SIZE + 2);
 	return lanczos_table[table_pos_int] +
@@ -109,7 +109,7 @@ unsigned gcd(unsigned a, unsigned b)
 }
 
 template<class DestFloat>
-unsigned combine_samples(const Tap<float> *src, Tap<DestFloat> *dst, float num_subtexels, float inv_num_subtexels, unsigned num_src_samples, unsigned max_samples_saved)
+unsigned combine_samples(const Tap<float> *src, Tap<DestFloat> *dst, float num_subtexels, float inv_num_subtexels, unsigned num_src_samples, unsigned max_samples_saved, float pos1_pos2_diff, float inv_pos1_pos2_diff)
 {
 	// Cut off near-zero values at both sides.
 	unsigned num_samples_saved = 0;
@@ -157,7 +157,7 @@ unsigned combine_samples(const Tap<float> *src, Tap<DestFloat> *dst, float num_s
 
 		DestFloat pos, total_weight;
 		float sum_sq_error;
-		combine_two_samples(w1, w2, pos1, pos2, num_subtexels, inv_num_subtexels, &pos, &total_weight, &sum_sq_error);
+		combine_two_samples(w1, w2, pos1, pos1_pos2_diff, inv_pos1_pos2_diff, num_subtexels, inv_num_subtexels, &pos, &total_weight, &sum_sq_error);
 
 		// If the interpolation error is larger than that of about sqrt(2) of
 		// a level at 8-bit precision, don't combine. (You'd think 1.0 was enough,
@@ -210,10 +210,12 @@ unsigned combine_many_samples(const Tap<float> *weights, unsigned src_size, unsi
 {
 	float num_subtexels = src_size / movit_texel_subpixel_precision;
 	float inv_num_subtexels = movit_texel_subpixel_precision / src_size;
+	float pos1_pos2_diff = 1.0f / src_size;
+	float inv_pos1_pos2_diff = src_size;
 
 	unsigned max_samples_saved = UINT_MAX;
 	for (unsigned y = 0; y < dst_samples && max_samples_saved > 0; ++y) {
-		unsigned num_samples_saved = combine_samples<DestFloat>(weights + y * src_samples, NULL, num_subtexels, inv_num_subtexels, src_samples, max_samples_saved);
+		unsigned num_samples_saved = combine_samples<DestFloat>(weights + y * src_samples, NULL, num_subtexels, inv_num_subtexels, src_samples, max_samples_saved, pos1_pos2_diff, inv_pos1_pos2_diff);
 		max_samples_saved = min(max_samples_saved, num_samples_saved);
 	}
 
@@ -228,7 +230,9 @@ unsigned combine_many_samples(const Tap<float> *weights, unsigned src_size, unsi
 			num_subtexels,
 			inv_num_subtexels,
 			src_samples,
-			max_samples_saved);
+			max_samples_saved,
+			pos1_pos2_diff,
+			inv_pos1_pos2_diff);
 		assert(num_samples_saved == max_samples_saved);
 		normalize_sum(bilinear_weights_ptr, src_bilinear_samples);
 	}
@@ -249,10 +253,10 @@ double compute_sum_sq_error(const Tap<float>* weights, unsigned num_weights,
 	// Find the effective range of the bilinear-optimized kernel.
 	// Due to rounding of the positions, this is not necessarily the same
 	// as the intended range (ie., the range of the original weights).
-	int lower_pos = int(floor(to_fp32(bilinear_weights[0].pos) * size - 0.5));
-	int upper_pos = int(ceil(to_fp32(bilinear_weights[num_bilinear_weights - 1].pos) * size - 0.5)) + 2;
-	lower_pos = min<int>(lower_pos, lrintf(weights[0].pos * size - 0.5));
-	upper_pos = max<int>(upper_pos, lrintf(weights[num_weights - 1].pos * size - 0.5) + 1);
+	int lower_pos = int(floor(to_fp32(bilinear_weights[0].pos) * size - 0.5f));
+	int upper_pos = int(ceil(to_fp32(bilinear_weights[num_bilinear_weights - 1].pos) * size - 0.5f)) + 2;
+	lower_pos = min<int>(lower_pos, lrintf(weights[0].pos * size - 0.5f));
+	upper_pos = max<int>(upper_pos, lrintf(weights[num_weights - 1].pos * size - 0.5f) + 1);
 
 	float* effective_weights = new float[upper_pos - lower_pos];
 	for (int i = 0; i < upper_pos - lower_pos; ++i) {
@@ -271,7 +275,7 @@ double compute_sum_sq_error(const Tap<float>* weights, unsigned num_weights,
 		assert(x0 < upper_pos - lower_pos);
 		assert(x1 < upper_pos - lower_pos);
 
-		effective_weights[x0] += to_fp32(bilinear_weights[i].weight) * (1.0 - f);
+		effective_weights[x0] += to_fp32(bilinear_weights[i].weight) * (1.0f - f);
 		effective_weights[x1] += to_fp32(bilinear_weights[i].weight) * f;
 	}
 
@@ -638,11 +642,12 @@ ScalingWeights calculate_scaling_weights(unsigned src_size, unsigned dst_size, f
 		int base_src_y = lrintf(center_src_y);
 
 		// Now sample <int_radius> pixels on each side around that point.
+		float inv_src_size = 1.0 / float(src_size);
 		for (int i = 0; i < src_samples; ++i) {
 			int src_y = base_src_y + i - int_radius;
 			float weight = lanczos_weight_cached(radius_scaling_factor * (src_y - center_src_y - subpixel_offset));
 			weights[y * src_samples + i].weight = weight * radius_scaling_factor;
-			weights[y * src_samples + i].pos = (src_y + 0.5) / float(src_size);
+			weights[y * src_samples + i].pos = (src_y + 0.5f) * inv_src_size;
 		}
 	}