Range for loop instead of explicit indexing

apps/yimage/yimage.cpp

@@ -200,7 +200,7 @@ void run_setalpha(const setalpha_params& params) {
 
   // edit alpha
   auto out = make_image(image.width, image.height, image.linear);
-  for (auto idx = (size_t)0; idx < image.pixels.size(); idx++) {
+  for (auto idx : range(image.pixels.size())) {
     auto calpha = alpha.pixels[idx];
     auto alpha_ = params.from_color   ? mean(xyz(calpha))
                   : params.from_black ? (mean(xyz(calpha)) > 0.01 ? 1.0f : 0.0f)

apps/ymesh/ymesh.cpp

@@ -1073,7 +1073,7 @@ static pair<vector<shape_point>, vec2f> sample_stroke(const bvh_tree& bvh,
   auto update_uv = (mouse_uv - last_uv) * stroke_dist / delta_pos;
   auto cur_uv    = last_uv;
   auto samples   = vector<shape_point>{};
-  for (auto step = 0; step < steps; step++) {
+  for (auto step : range(steps)) {
     cur_uv += update_uv;
     auto isec = intersect_shape(cur_uv);
     if (!isec.hit) continue;

apps/yscene/yscene.cpp

@@ -215,7 +215,7 @@ void run_render(const render_params& params_) {
 
   // render
   timer = simple_timer{};
-  for (auto sample = 0; sample < params.samples; sample++) {
+  for (auto sample : range(params.samples)) {
     auto sample_timer = simple_timer{};
     trace_samples(state, scene, bvh, lights, params);
     print_info("render sample {}/{}: {}", sample, params.samples,

libs/yocto/yocto_bvh.cpp

@@ -125,7 +125,7 @@ static pair<int, int> split_sah(vector<int>& primitives,
     return 1e-12f + 2 * size.x * size.y + 2 * size.x * size.z +
            2 * size.y * size.z;
   };
-  for (auto saxis = 0; saxis < 3; saxis++) {
+  for (auto saxis : range(3)) {
     for (auto b = 1; b < nbins; b++) {
       auto bsplit    = cbbox.min[saxis] + b * csize[saxis] / nbins;
       auto left_bbox = invalidb3f, right_bbox = invalidb3f;
@@ -303,11 +303,11 @@ static void refit_bvh(vector<bvh_node>& nodes, const vector<int>& primitives,
     auto& node = nodes[nodeid];
     node.bbox  = invalidb3f;
     if (node.internal) {
-      for (auto idx = 0; idx < 2; idx++) {
+      for (auto idx : range(2)) {
         node.bbox = merge(node.bbox, nodes[node.start + idx].bbox);
       }
     } else {
-      for (auto idx = 0; idx < node.num; idx++) {
+      for (auto idx : range(node.num)) {
         node.bbox = merge(node.bbox, bboxes[primitives[node.start + idx]]);
       }
     }
@@ -365,7 +365,7 @@ scene_bvh make_scene_bvh(
   // build shape bvh
   bvh.shapes.resize(scene.shapes.size());
   if (noparallel) {
-    for (auto idx = (size_t)0; idx < scene.shapes.size(); idx++) {
+    for (auto idx : range(scene.shapes.size())) {
       bvh.shapes[idx] = make_shape_bvh(scene.shapes[idx], highquality);
     }
   } else {
@@ -654,7 +654,7 @@ shape_intersection overlap_shape_bvh(const shape_bvh& bvh,
       node_stack[node_cur++] = node.start + 0;
       node_stack[node_cur++] = node.start + 1;
     } else if (!shape.points.empty()) {
-      for (auto idx = 0; idx < node.num; idx++) {
+      for (auto idx : range(node.num)) {
         auto  primitive     = bvh.primitives[node.start + idx];
         auto& p             = shape.points[primitive];
         auto  eintersection = overlap_point(
@@ -665,7 +665,7 @@ shape_intersection overlap_shape_bvh(const shape_bvh& bvh,
         max_distance = eintersection.distance;
       }
     } else if (!shape.lines.empty()) {
-      for (auto idx = 0; idx < node.num; idx++) {
+      for (auto idx : range(node.num)) {
         auto  primitive     = bvh.primitives[node.start + idx];
         auto& l             = shape.lines[primitive];
         auto  eintersection = overlap_line(pos, max_distance,
@@ -677,7 +677,7 @@ shape_intersection overlap_shape_bvh(const shape_bvh& bvh,
         max_distance = eintersection.distance;
       }
     } else if (!shape.triangles.empty()) {
-      for (auto idx = 0; idx < node.num; idx++) {
+      for (auto idx : range(node.num)) {
         auto  primitive     = bvh.primitives[node.start + idx];
         auto& t             = shape.triangles[primitive];
         auto  eintersection = overlap_triangle(pos, max_distance,
@@ -689,7 +689,7 @@ shape_intersection overlap_shape_bvh(const shape_bvh& bvh,
         max_distance = eintersection.distance;
       }
     } else if (!shape.quads.empty()) {
-      for (auto idx = 0; idx < node.num; idx++) {
+      for (auto idx : range(node.num)) {
         auto  primitive     = bvh.primitives[node.start + idx];
         auto& q             = shape.quads[primitive];
         auto  eintersection = overlap_quad(pos, max_distance,
@@ -740,7 +740,7 @@ scene_intersection overlap_scene_bvh(const scene_bvh& bvh,
       node_stack[node_cur++] = node.start + 0;
       node_stack[node_cur++] = node.start + 1;
     } else {
-      for (auto idx = 0; idx < node.num; idx++) {
+      for (auto idx : range(node.num)) {
         auto  primitive = bvh.primitives[node.start + idx];
         auto& instance_ = scene.instances[primitive];
         auto& shape     = scene.shapes[instance_.shape];
@@ -973,7 +973,7 @@ scene_embree_bvh make_scene_embree_bvh(
   // shape bvhs
   bvh.shapes.resize(scene.shapes.size());
   if (noparallel) {
-    for (auto idx = (size_t)0; idx < scene.shapes.size(); idx++) {
+    for (auto idx : range(scene.shapes.size())) {
       bvh.shapes[idx] = make_shape_embree_bvh(scene.shapes[idx], highquality);
     }
   } else {

libs/yocto/yocto_cli.h

@@ -434,7 +434,7 @@ inline void add_option(cli_command& cli, const string& name, vector<T>& value,
   cli.options[name] = [&value](const vector<string>& args, string& error) {
     if (!_cli_parse_size(args, 1, 1024, error)) return false;
     value.resize(args.size());
-    for (auto idx = (size_t)0; idx < args.size(); idx++) {
+    for (auto idx = 0; idx < (int)args.size(); idx++) {
       if (!_cli_parse_value(args[idx], value[idx], error)) return false;
     }
     return true;
@@ -449,7 +449,7 @@ inline void add_option(cli_command& cli, const string& name, array<T, N>& value,
   cli.usage_options += _cli_usage_option(name, value, usage);
   cli.options[name] = [&value](const vector<string>& args, string& error) {
     if (!_cli_parse_size(args, N, N, error)) return false;
-    for (auto idx = (size_t)0; idx < args.size(); idx++) {
+    for (auto idx = 0; idx < (int)args.size(); idx++) {
       if (!_cli_parse_value(args[idx], value[idx], error)) return false;
     }
     return true;

libs/yocto/yocto_gui.cpp

@@ -479,7 +479,7 @@ void show_image_gui(const string& title, const vector<string>& names,
   auto displays  = vector<image_data>(images.size());
   auto exposures = vector<float>(images.size(), 0);
   auto filmics   = vector<bool>(images.size(), false);
-  for (auto idx = 0; idx < (int)images.size(); idx++) {
+  for (auto idx : range((int)images.size())) {
     displays[idx] = make_image(images[idx].width, images[idx].height, false);
     tonemap_image_mt(displays[idx], images[idx], exposures[idx], filmics[idx]);
   }
@@ -678,7 +678,7 @@ void show_trace_gui(const string& title, const string& name, scene_data& scene,
       for (auto sample = 0; sample < params.samples; sample += params.batch) {
         if (render_stop) return;
         parallel_for(state.width, state.height, [&](int i, int j) {
-          for (auto s = 0; s < params.batch; s++) {
+          for (auto s : range(params.batch)) {
             if (render_stop) return;
             trace_sample(state, scene, bvh, lights, i, j, params);
           }
@@ -2275,7 +2275,7 @@ bool draw_gui_combobox(const char* lbl, int& idx, int num,
     if (idx < 0) ImGui::SetItemDefaultFocus();
     ImGui::PopID();
   }
-  for (auto i = 0; i < num; i++) {
+  for (auto i : range(num)) {
     ImGui::PushID(i);
     if (ImGui::Selectable(labels(i).c_str(), idx == i)) idx = i;
     if (idx == i) ImGui::SetItemDefaultFocus();

libs/yocto/yocto_image.cpp

@@ -128,7 +128,7 @@ void convert_image(image_data& result, const image_data& image) {
   if (image.linear == result.linear) {
     result.pixels = image.pixels;
   } else {
-    for (auto idx = (size_t)0; idx < image.pixels.size(); idx++) {
+    for (auto idx : range(image.pixels.size())) {
       result.pixels[idx] = image.linear ? rgb_to_srgb(image.pixels[idx])
                                         : srgb_to_rgb(image.pixels[idx]);
     }
@@ -198,12 +198,12 @@ void tonemap_image(
     throw std::invalid_argument{"image should be the same size"};
   if (result.linear) throw std::invalid_argument{"ldr expected"};
   if (image.linear) {
-    for (auto idx = (size_t)0; idx < image.pixels.size(); idx++) {
+    for (auto idx : range(image.pixels.size())) {
       result.pixels[idx] = tonemap(image.pixels[idx], exposure, filmic);
     }
   } else {
     auto scale = vec4f{pow(2, exposure), pow(2, exposure), pow(2, exposure), 1};
-    for (auto idx = (size_t)0; idx < image.pixels.size(); idx++) {
+    for (auto idx : range(image.pixels.size())) {
       result.pixels[idx] = image.pixels[idx] * scale;
     }
   }
@@ -265,7 +265,7 @@ image_data image_difference(
 
   // compute diff
   auto difference = make_image(image1.width, image1.height, image1.linear);
-  for (auto idx = (size_t)0; idx < difference.pixels.size(); idx++) {
+  for (auto idx : range(difference.pixels.size())) {
     auto diff              = abs(image1.pixels[idx] - image2.pixels[idx]);
     difference.pixels[idx] = display ? vec4f{max(diff), max(diff), max(diff), 1}
                                      : diff;
@@ -274,8 +274,8 @@ image_data image_difference(
 }
 
 void set_region(image_data& image, const image_data& region, int x, int y) {
-  for (auto j = 0; j < region.height; j++) {
-    for (auto i = 0; i < region.width; i++) {
+  for (auto j : range(region.height)) {
+    for (auto i : range(region.width)) {
       image.pixels[(j + y) * image.width + (i + x)] =
           region.pixels[j * region.width + i];
     }
@@ -287,8 +287,8 @@ void get_region(image_data& region, const image_data& image, int x, int y,
   if (region.width != width || region.height != height) {
     region = make_image(width, height, image.linear);
   }
-  for (auto j = 0; j < height; j++) {
-    for (auto i = 0; i < width; i++) {
+  for (auto j : range(height)) {
+    for (auto i : range(width)) {
       region.pixels[j * region.width + i] =
           image.pixels[(j + y) * image.width + (i + x)];
     }
@@ -303,7 +303,7 @@ image_data composite_image(
   if (image_a.linear != image_b.linear)
     throw std::invalid_argument{"image should be of the same type"};
   auto result = make_image(image_a.width, image_a.height, image_a.linear);
-  for (auto idx = (size_t)0; idx < result.pixels.size(); idx++) {
+  for (auto idx : range(result.pixels.size())) {
     result.pixels[idx] = composite(image_a.pixels[idx], image_b.pixels[idx]);
   }
   return result;
@@ -320,7 +320,7 @@ void composite_image(
     throw std::invalid_argument{"image should be the same size"};
   if (image_a.linear != result.linear)
     throw std::invalid_argument{"image should be of the same type"};
-  for (auto idx = (size_t)0; idx < result.pixels.size(); idx++) {
+  for (auto idx : range(result.pixels.size())) {
     result.pixels[idx] = composite(image_a.pixels[idx], image_b.pixels[idx]);
   }
 }
@@ -365,7 +365,7 @@ vec4f colorgradeb(
 image_data colorgrade_image(
     const image_data& image, const colorgrade_params& params) {
   auto result = make_image(image.width, image.height, false);
-  for (auto idx = (size_t)0; idx < image.pixels.size(); idx++) {
+  for (auto idx : range(image.pixels.size())) {
     result.pixels[idx] = colorgrade(image.pixels[idx], image.linear, params);
   }
   return result;
@@ -378,7 +378,7 @@ void colorgrade_image(image_data& result, const image_data& image,
   if (image.width != result.width || image.height != result.height)
     throw std::invalid_argument{"image should be the same size"};
   if (!!result.linear) throw std::invalid_argument{"non linear expected"};
-  for (auto idx = (size_t)0; idx < image.pixels.size(); idx++) {
+  for (auto idx : range(image.pixels.size())) {
     result.pixels[idx] = colorgrade(image.pixels[idx], image.linear, params);
   }
 }
@@ -452,8 +452,8 @@ static image_data make_proc_image(
     int width, int height, bool linear, Shader&& shader) {
   auto image = make_image(width, height, linear);
   auto scale = 1.0f / max(width, height);
-  for (auto j = 0; j < height; j++) {
-    for (auto i = 0; i < width; i++) {
+  for (auto j : range(height)) {
+    for (auto i : range(width)) {
       auto uv                     = vec2f{i * scale, j * scale};
       image.pixels[j * width + i] = shader(uv);
     }
@@ -637,8 +637,8 @@ image_data add_border(
     const image_data& image, float width, const vec4f& color) {
   auto result = image;
   auto scale  = 1.0f / max(image.width, image.height);
-  for (auto j = 0; j < image.height; j++) {
-    for (auto i = 0; i < image.width; i++) {
+  for (auto j : range(image.height)) {
+    for (auto i : range(image.width)) {
       auto uv = vec2f{i * scale, j * scale};
       if (uv.x < width || uv.y < width || uv.x > image.width * scale - width ||
           uv.y > image.height * scale - width) {
@@ -798,7 +798,7 @@ image_data make_lights(int width, int height, const vec3f& le, int nlights,
     for (int i = 0; i < width; i++) {
       auto phi     = 2 * pif * (float(i + 0.5f) / width);
       auto inlight = false;
-      for (auto l = 0; l < nlights; l++) {
+      for (auto l : range(nlights)) {
         auto lphi = 2 * pif * (l + 0.5f) / nlights;
         inlight   = inlight || fabs(phi - lphi) < lwidth / 2;
       }
@@ -1045,8 +1045,8 @@ static void make_proc_image(
     vector<vec4f>& pixels, int width, int height, Shader&& shader) {
   pixels.resize((size_t)width * (size_t)height);
   auto scale = 1.0f / max(width, height);
-  for (auto j = 0; j < height; j++) {
-    for (auto i = 0; i < width; i++) {
+  for (auto j : range(height)) {
+    for (auto i : range(width)) {
       auto uv               = vec2f{i * scale, j * scale};
       pixels[j * width + i] = shader(uv);
     }
@@ -1231,8 +1231,8 @@ void add_border(vector<vec4f>& pixels, const vector<vec4f>& source, int width,
     int height, float thickness, const vec4f& color) {
   pixels     = source;
   auto scale = 1.0f / max(width, height);
-  for (auto j = 0; j < height; j++) {
-    for (auto i = 0; i < width; i++) {
+  for (auto j : range(height)) {
+    for (auto i : range(width)) {
       auto uv = vec2f{i * scale, j * scale};
       if (uv.x < thickness || uv.y < thickness ||
           uv.x > width * scale - thickness ||
@@ -1389,7 +1389,7 @@ void make_lights(vector<vec4f>& pixels, int width, int height, const vec3f& le,
     for (int i = 0; i < width; i++) {
       auto phi     = 2 * pif * (float(i + 0.5f) / width);
       auto inlight = false;
-      for (auto l = 0; l < nlights; l++) {
+      for (auto l : range(nlights)) {
         auto lphi = 2 * pif * (l + 0.5f) / nlights;
         inlight   = inlight || fabs(phi - lphi) < lwidth / 2;
       }