From 302896d4884896128ffe59257bb64b4f5af8aae5 Mon Sep 17 00:00:00 2001 From: ocornut Date: Thu, 27 Aug 2020 12:19:13 +0200 Subject: [PATCH] Basic optimization for ShadeVertsLinearColorGradientKeepAlpha() - especially for debug overhead - since it's used massively by some of our experiments. --- imgui_draw.cpp | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/imgui_draw.cpp b/imgui_draw.cpp index bb300e00..5b79a449 100644 --- a/imgui_draw.cpp +++ b/imgui_draw.cpp @@ -1599,13 +1599,19 @@ void ImGui::ShadeVertsLinearColorGradientKeepAlpha(ImDrawList* draw_list, int ve float gradient_inv_length2 = 1.0f / ImLengthSqr(gradient_extent); ImDrawVert* vert_start = draw_list->VtxBuffer.Data + vert_start_idx; ImDrawVert* vert_end = draw_list->VtxBuffer.Data + vert_end_idx; + const int col0_r = (int)(col0 >> IM_COL32_R_SHIFT) & 0xFF; + const int col0_g = (int)(col0 >> IM_COL32_G_SHIFT) & 0xFF; + const int col0_b = (int)(col0 >> IM_COL32_B_SHIFT) & 0xFF; + const int col_delta_r = ((int)(col1 >> IM_COL32_R_SHIFT) & 0xFF) - col0_r; + const int col_delta_g = ((int)(col1 >> IM_COL32_G_SHIFT) & 0xFF) - col0_g; + const int col_delta_b = ((int)(col1 >> IM_COL32_B_SHIFT) & 0xFF) - col0_b; for (ImDrawVert* vert = vert_start; vert < vert_end; vert++) { float d = ImDot(vert->pos - gradient_p0, gradient_extent); float t = ImClamp(d * gradient_inv_length2, 0.0f, 1.0f); - int r = ImLerp((int)(col0 >> IM_COL32_R_SHIFT) & 0xFF, (int)(col1 >> IM_COL32_R_SHIFT) & 0xFF, t); - int g = ImLerp((int)(col0 >> IM_COL32_G_SHIFT) & 0xFF, (int)(col1 >> IM_COL32_G_SHIFT) & 0xFF, t); - int b = ImLerp((int)(col0 >> IM_COL32_B_SHIFT) & 0xFF, (int)(col1 >> IM_COL32_B_SHIFT) & 0xFF, t); + int r = (int)(col0_r + col_delta_r * t); + int g = (int)(col0_g + col_delta_g * t); + int b = (int)(col0_b + col_delta_b * t); vert->col = (r << IM_COL32_R_SHIFT) | (g << IM_COL32_G_SHIFT) | (b << IM_COL32_B_SHIFT) | (vert->col & IM_COL32_A_MASK); } }