psppixelformat.h

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef PSP_PIXEL_FORMAT_H
#define PSP_PIXEL_FORMAT_H

#include "graphics/pixelformat.h"
#include "backends/platform/psp/trace.h"

struct PSPPixelFormat {
    enum Type {
        Type_None,
        Type_4444,
        Type_5551,
        Type_5650,
        Type_8888,
        Type_Palette_8bit,
        Type_Palette_4bit,
        Type_Unknown
    };

    Type format;
    uint32 bitsPerPixel;                    

    PSPPixelFormat() : format(Type_Unknown), bitsPerPixel(0) {}
    void set(Type type);
    static void convertFromScummvmPixelFormat(const Graphics::PixelFormat *pf,
            PSPPixelFormat::Type &bufferType,
            PSPPixelFormat::Type &paletteType,
        bool &fakeAlpha);
    static Graphics::PixelFormat convertToScummvmPixelFormat(PSPPixelFormat::Type type, bool fakeAlpha = false);

    inline uint32 rgbaToColor(uint32 r, uint32 g, uint32 b, uint32 a) const {
        uint32 color;

        switch (format) {
        case Type_4444:
            color = (((b >> 4) << 8) | ((g >> 4) << 4) | ((r >> 4) << 0) | ((a >> 4) << 12));
            break;
        case Type_5551:
            color = (((b >> 3) << 10) | ((g >> 3) << 5) | ((r >> 3) << 0) | ((a >> 7) << 15));
            break;
        case Type_5650:
            color = (((b >> 3) << 11) | ((g >> 2) << 5) | ((r >> 3) << 0));
            break;
        case Type_8888:
            color = (((b >> 0) << 16) | ((g >> 0) << 8) | ((r >> 0) << 0) | ((a >> 0) << 24));
            break;
        default:
            color = 0;
            break;
        }
        return color;
    }

    inline void colorToRgba(uint32 color, uint32 &r, uint32 &g, uint32 &b, uint32 &a) const {
        switch (format) {
        case Type_4444:
            a = (color >> 12) & 0xF; // Interpolate to get true colors
            b = (color >> 8)  & 0xF;
            g = (color >> 4)  & 0xF;
            r = (color >> 0)  & 0xF;
            a = a << 4 | a;
            b = b << 4 | b;
            g = g << 4 | g;
            r = r << 4 | r;
            break;
        case Type_5551:
            a = (color >> 15) ? 0xFF : 0;
            b = (color >> 10) & 0x1F;
            g = (color >> 5)  & 0x1F;
            r = (color >> 0)  & 0x1F;
            b = b << 3 | b >> 2;
            g = g << 3 | g >> 2;
            r = r << 3 | r >> 2;
            break;
        case Type_5650:
            a = 0xFF;
            b = (color >> 11) & 0x1F;
            g = (color >> 5)  & 0x3F;
            r = (color >> 0)  & 0x1F;
            b = b << 3 | b >> 2;
            g = g << 2 | g >> 4;
            r = r << 3 | r >> 2;
            break;
        case Type_8888:
            a = (color >> 24) & 0xFF;
            b = (color >> 16) & 0xFF;
            g = (color >> 8)  & 0xFF;
            r = (color >> 0)  & 0xFF;
            break;
        default:
            a = b = g = r = 0;
            break;
        }
    }

    inline uint32 setColorAlpha(uint32 color, byte alpha) {
        switch (format) {
        case Type_4444:
            color = (color & 0x0FFF) | (((uint32)alpha >> 4) << 12);
            break;
        case Type_5551:
            color = (color & 0x7FFF) | (((uint32)alpha >> 7) << 15);
            break;
        case Type_8888:
            color = (color & 0x00FFFFFF) | ((uint32)alpha << 24);
            break;
        case Type_5650:
        default:
            break;
        }
        return color;
    }

    inline uint32 pixelsToBytes(uint32 pixels) const {
        switch (bitsPerPixel) {
        case 4:
            pixels >>= 1;
            break;
        case 16:
            pixels <<= 1;
            break;
        case 32:
            pixels <<= 2;
            break;
        case 8:
            break;
        default:
            PSP_ERROR("Incorrect bitsPerPixel value[%u]. pixels[%u]\n", bitsPerPixel, pixels);
            break;
        }
        return pixels;
    }

    // Return whatever color we point at
    inline uint32 getColorValueAt(byte *pointer) const {
        uint32 result;

        switch (bitsPerPixel) {
        case 4: // We can't distinguish a 4 bit color with a pointer
        case 8:
            result = *pointer;
            break;
        case 16:
            result = *(uint16 *)pointer;
            break;
        case 32:
            result = *(uint32 *)pointer;
            break;
        default:
            result = 0;
            PSP_ERROR("Incorrect bitsPerPixel value[%u].\n", bitsPerPixel);
            break;
        }
        return result;
    }
};

#endif /* PSP_PIXEL_FORMAT_H */