129 lines
4.5 KiB
C++
129 lines
4.5 KiB
C++
/* ScummVM - Graphic Adventure Engine
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*
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* ScummVM is the legal property of its developers, whose names
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* are too numerous to list here. Please refer to the COPYRIGHT
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* file distributed with this source distribution.
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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*/
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#include "common/std/memory.h"
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#include "ags/shared/core/platform.h"
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#include "ags/engine/gfx/gfx_util.h"
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#include "ags/engine/gfx/blender.h"
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namespace AGS3 {
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namespace AGS {
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namespace Engine {
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using namespace Shared;
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namespace GfxUtil {
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Bitmap *ConvertBitmap(Bitmap *src, int dst_color_depth) {
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int src_col_depth = src->GetColorDepth();
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if (src_col_depth != dst_color_depth) {
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int old_conv = get_color_conversion();
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// TODO: find out what is this, and why do we need to call this every time (do we?)
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set_color_conversion(COLORCONV_KEEP_TRANS | COLORCONV_TOTAL);
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Bitmap *dst = BitmapHelper::CreateBitmapCopy(src, dst_color_depth);
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set_color_conversion(old_conv);
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return dst;
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}
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return src;
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}
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struct BlendModeSetter {
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// Blender setter for destination with and without alpha channel;
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// assign kRgbToRgbBlender if not supported
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BlenderMode AllAlpha; // src w alpha -> dst w alpha
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BlenderMode AlphaToOpaque; // src w alpha -> dst w/o alpha
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BlenderMode OpaqueToAlpha; // src w/o alpha -> dst w alpha
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BlenderMode OpaqueToAlphaNoTrans; // src w/o alpha -> dst w alpha (opt-ed for no transparency)
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BlenderMode AllOpaque; // src w/o alpha -> dst w/o alpha
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};
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// Array of blender descriptions
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// NOTE: set kRgbToRgbBlender to fallback to common image blitting
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static const BlendModeSetter BlendModeSets[kNumBlendModes] = {
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{ kRgbToRgbBlender, kRgbToRgbBlender, kRgbToRgbBlender, kRgbToRgbBlender, kRgbToRgbBlender }, // kBlendMode_NoAlpha
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{ kArgbToArgbBlender, kArgbToRgbBlender, kRgbToArgbBlender, kOpaqueBlenderMode, kRgbToRgbBlender }, // kBlendMode_Alpha
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// NOTE: add new modes here
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};
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bool SetBlender(BlendMode blend_mode, bool dst_has_alpha, bool src_has_alpha, int blend_alpha) {
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if (blend_mode < 0 || blend_mode >= kNumBlendModes)
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return false;
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const BlendModeSetter &set = BlendModeSets[blend_mode];
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BlenderMode blender;
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if (dst_has_alpha)
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blender = src_has_alpha ? set.AllAlpha :
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(blend_alpha == 0xFF ? set.OpaqueToAlphaNoTrans : set.OpaqueToAlpha);
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else
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blender = src_has_alpha ? set.AlphaToOpaque : set.AllOpaque;
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set_blender_mode(blender, 0, 0, 0, blend_alpha);
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return true;
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}
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void DrawSpriteBlend(Bitmap *ds, const Point &ds_at, Bitmap *sprite,
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BlendMode blend_mode, bool dst_has_alpha, bool src_has_alpha, int blend_alpha) {
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if (blend_alpha <= 0)
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return; // do not draw 100% transparent image
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if (// support only 32-bit blending at the moment
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ds->GetColorDepth() == 32 && sprite->GetColorDepth() == 32 &&
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// set blenders if applicable and tell if succeeded
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SetBlender(blend_mode, dst_has_alpha, src_has_alpha, blend_alpha)) {
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ds->TransBlendBlt(sprite, ds_at.X, ds_at.Y);
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} else {
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GfxUtil::DrawSpriteWithTransparency(ds, sprite, ds_at.X, ds_at.Y, blend_alpha);
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}
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}
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void DrawSpriteWithTransparency(Bitmap *ds, Bitmap *sprite, int x, int y, int alpha) {
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if (alpha <= 0) {
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// fully transparent, don't draw it at all
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return;
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}
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const int surface_depth = ds->GetColorDepth();
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const int sprite_depth = sprite->GetColorDepth();
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// Allegro does not support masked blit or blend between different formats
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// *except* when drawing 8-bit sprites onto a higher dest.
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std::unique_ptr<Bitmap> conv_bm;
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if ((surface_depth != sprite_depth) && (sprite_depth > 8)) {
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// use ConvertBitmap in order to keep mask pixels
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conv_bm.reset(ConvertBitmap(sprite, surface_depth));
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sprite = conv_bm.get();
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}
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if ((alpha < 0xFF) && (surface_depth > 8) && (sprite_depth > 8)) {
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set_trans_blender(0, 0, 0, alpha);
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ds->TransBlendBlt(sprite, x, y);
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} else {
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ds->Blit(sprite, x, y, kBitmap_Transparency);
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}
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}
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} // namespace GfxUtil
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} // namespace Engine
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} // namespace AGS
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} // namespace AGS3
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