ColorPicker: Rearrange code to introduce alternate HSV picker/selector with simpler diff. (#346)

imgui.cpp

@@ -9385,22 +9385,25 @@ bool ImGui::ColorPicker4(const char* label, float col[4], ImGuiColorEditFlags fl
     ColorConvertRGBtoHSV(col[0], col[1], col[2], H, S, V);
 
     // Color matrix logic
-    bool value_changed = false, hsv_changed = false, value_changed_from_matrix = false;
-    InvisibleButton("sv", ImVec2(sv_picker_size, sv_picker_size));
-    if (IsItemActive())
-    {
-        S = ImSaturate((io.MousePos.x - picker_pos.x) / (sv_picker_size-1));
-        V = 1.0f - ImSaturate((io.MousePos.y - picker_pos.y) / (sv_picker_size-1));
-        value_changed = hsv_changed = value_changed_from_matrix = true;
-    }
+    bool value_changed = false, value_changed_h = false, value_changed_sv = false;
 
-    // Hue bar logic
-    SetCursorScreenPos(ImVec2(bar0_pos_x, picker_pos.y));
-    InvisibleButton("hue", ImVec2(bars_width, sv_picker_size));
-    if (IsItemActive())
     {
-        H = ImSaturate((io.MousePos.y - picker_pos.y) / (sv_picker_size-1));
-        value_changed = hsv_changed = true;
+        InvisibleButton("sv", ImVec2(sv_picker_size, sv_picker_size));
+        if (IsItemActive())
+        {
+            S = ImSaturate((io.MousePos.x - picker_pos.x) / (sv_picker_size-1));
+            V = 1.0f - ImSaturate((io.MousePos.y - picker_pos.y) / (sv_picker_size-1));
+            value_changed = value_changed_sv = true;
+        }
+
+        // Hue bar logic
+        SetCursorScreenPos(ImVec2(bar0_pos_x, picker_pos.y));
+        InvisibleButton("hue", ImVec2(bars_width, sv_picker_size));
+        if (IsItemActive())
+        {
+            H = ImSaturate((io.MousePos.y - picker_pos.y) / (sv_picker_size-1));
+            value_changed = value_changed_h = true;
+        }
     }
 
     // Alpha bar logic
@@ -9453,7 +9456,7 @@ bool ImGui::ColorPicker4(const char* label, float col[4], ImGuiColorEditFlags fl
     }
 
     // Convert back color to RGB
-    if (hsv_changed)
+    if (value_changed_h || value_changed_sv)
         ColorConvertHSVtoRGB(H >= 1.0f ? H - 10 * 1e-6f : H, S > 0.0f ? S : 10*1e-6f, V > 0.0f ? V : 1e-6f, col[0], col[1], col[2]);
 
     // R,G,B and H,S,V slider color editor
@@ -9493,27 +9496,30 @@ bool ImGui::ColorPicker4(const char* label, float col[4], ImGuiColorEditFlags fl
     ImU32 hue_color32 = ColorConvertFloat4ToU32(hue_color_f);
     ImU32 col32_no_alpha = ColorConvertFloat4ToU32(ImVec4(col[0], col[1], col[2], 1.0f));
 
-    // Render color matrix
-    draw_list->AddRectFilledMultiColor(picker_pos, picker_pos + ImVec2(sv_picker_size,sv_picker_size), IM_COL32_WHITE, hue_color32, hue_color32, IM_COL32_WHITE);
-    draw_list->AddRectFilledMultiColor(picker_pos, picker_pos + ImVec2(sv_picker_size,sv_picker_size), IM_COL32_BLACK_TRANS, IM_COL32_BLACK_TRANS, IM_COL32_BLACK, IM_COL32_BLACK);
-    RenderFrameBorder(picker_pos, picker_pos + ImVec2(sv_picker_size,sv_picker_size), 0.0f);
-
-    // Render cursor/preview circle  (clamp S/V within 0..1 range because floating points colors may lead HSV values to be out of range)
-    ImVec2 p((float)(int)(picker_pos.x + ImSaturate(S) * sv_picker_size + 0.5f), (float)(int)(picker_pos.y + ImSaturate(1 - V) * sv_picker_size + 0.5f));
-    p.x = ImClamp(p.x, picker_pos.x + 2, picker_pos.x + sv_picker_size - 2); // Sneakily prevent the circle to stick out too much
-    p.y = ImClamp(p.y, picker_pos.y + 2, picker_pos.y + sv_picker_size - 2);
-    float r = value_changed_from_matrix ? 10.0f : 6.0f;
-    draw_list->AddCircleFilled(p, r, col32_no_alpha, 12);
-    draw_list->AddCircle(p, r+1, IM_COL32(128,128,128,255), 12);
-    draw_list->AddCircle(p, r, IM_COL32_WHITE, 12);
-
-    // Render hue bar
-    ImU32 hue_bar_colors[6+1] = { IM_COL32(255,0,0,255), IM_COL32(255,255,0,255), IM_COL32(0,255,0,255), IM_COL32(0,255,255,255), IM_COL32(0,0,255,255), IM_COL32(255,0,255,255), IM_COL32(255,0,0,255) };
-    for (int i = 0; i < 6; ++i)
-        draw_list->AddRectFilledMultiColor(ImVec2(bar0_pos_x, picker_pos.y + i * (sv_picker_size / 6)), ImVec2(bar0_pos_x + bars_width, picker_pos.y + (i + 1) * (sv_picker_size / 6)), hue_bar_colors[i], hue_bar_colors[i], hue_bar_colors[i + 1], hue_bar_colors[i + 1]);
-    float bar0_line_y = (float)(int)(picker_pos.y + H * sv_picker_size + 0.5f);
-    RenderFrameBorder(ImVec2(bar0_pos_x, picker_pos.y), ImVec2(bar0_pos_x + bars_width, picker_pos.y + sv_picker_size), 0.0f);
-    RenderArrowsForVerticalBar(draw_list, ImVec2(bar0_pos_x - 1, bar0_line_y), ImVec2(bars_triangles_half_sz + 1, bars_triangles_half_sz), bars_width + 2.0f);
+    const ImU32 hue_colors[6+1] = { IM_COL32(255,0,0,255), IM_COL32(255,255,0,255), IM_COL32(0,255,0,255), IM_COL32(0,255,255,255), IM_COL32(0,0,255,255), IM_COL32(255,0,255,255), IM_COL32(255,0,0,255) };
+    ImVec2 sv_cursor_pos;
+    
+    {
+        // Render SV Square
+        draw_list->AddRectFilledMultiColor(picker_pos, picker_pos + ImVec2(sv_picker_size,sv_picker_size), IM_COL32_WHITE, hue_color32, hue_color32, IM_COL32_WHITE);
+        draw_list->AddRectFilledMultiColor(picker_pos, picker_pos + ImVec2(sv_picker_size,sv_picker_size), IM_COL32_BLACK_TRANS, IM_COL32_BLACK_TRANS, IM_COL32_BLACK, IM_COL32_BLACK);
+        RenderFrameBorder(picker_pos, picker_pos + ImVec2(sv_picker_size,sv_picker_size), 0.0f);
+        sv_cursor_pos.x = ImClamp((float)(int)(picker_pos.x + ImSaturate(S)     * sv_picker_size + 0.5f), picker_pos.x + 2, picker_pos.x + sv_picker_size - 2); // Sneakily prevent the circle to stick out too much
+        sv_cursor_pos.y = ImClamp((float)(int)(picker_pos.y + ImSaturate(1 - V) * sv_picker_size + 0.5f), picker_pos.y + 2, picker_pos.y + sv_picker_size - 2);
+
+        // Render Hue Bar
+        for (int i = 0; i < 6; ++i)
+            draw_list->AddRectFilledMultiColor(ImVec2(bar0_pos_x, picker_pos.y + i * (sv_picker_size / 6)), ImVec2(bar0_pos_x + bars_width, picker_pos.y + (i + 1) * (sv_picker_size / 6)), hue_colors[i], hue_colors[i], hue_colors[i + 1], hue_colors[i + 1]);
+        float bar0_line_y = (float)(int)(picker_pos.y + H * sv_picker_size + 0.5f);
+        RenderFrameBorder(ImVec2(bar0_pos_x, picker_pos.y), ImVec2(bar0_pos_x + bars_width, picker_pos.y + sv_picker_size), 0.0f);
+        RenderArrowsForVerticalBar(draw_list, ImVec2(bar0_pos_x - 1, bar0_line_y), ImVec2(bars_triangles_half_sz + 1, bars_triangles_half_sz), bars_width + 2.0f);
+    }
+
+    // Render cursor/preview circle (clamp S/V within 0..1 range because floating points colors may lead HSV values to be out of range)
+    float sv_cursor_rad = value_changed_sv ? 10.0f : 6.0f;
+    draw_list->AddCircleFilled(sv_cursor_pos, sv_cursor_rad, col32_no_alpha, 12);
+    draw_list->AddCircle(sv_cursor_pos, sv_cursor_rad+1, IM_COL32(128,128,128,255), 12);
+    draw_list->AddCircle(sv_cursor_pos, sv_cursor_rad, IM_COL32_WHITE, 12);
 
     // Render alpha bar
     if (alpha_bar)