DustEntity.m

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/*
 
DustEntity.m
 
Oolite
Copyright (C) 2004-2013 Giles C Williams and contributors
 
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 2
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, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
MA 02110-1301, USA.
 
*/
 
#import "DustEntity.h"
 
#import "OOMaths.h"
#import "Universe.h"
#import "MyOpenGLView.h"
#import "OOGraphicsResetManager.h"
#import "OODebugFlags.h"
#import "OOMacroOpenGL.h"
 
 
#if OO_SHADERS
#import "OOMaterial.h"      // For kTangentAttributeIndex
#import "OOShaderProgram.h"
#import "OOShaderUniform.h"
#endif
 
#import "PlayerEntity.h"
 
 
#define FAR_PLANE       (DUST_SCALE * 0.50f)
#define NEAR_PLANE      (DUST_SCALE * 0.25f)
 
 
// Declare protocol conformance
@interface DustEntity (Private) <OOGraphicsResetClient>
 
- (void) checkShaderMode;
 
@end
 
#if OO_SHADERS
enum
{
    kShaderModeOff,
    kShaderModeOn,
    kShaderModeUnknown
};
#endif
 
 
@implementation DustEntity
 
- (id) init
{
    int vi;
    
// this should be unnecessary
//  ranrot_srand((uint32_t)[[NSDate date] timeIntervalSince1970]);  // seed randomiser by time
    
    self = [super init];
    
    for (vi = 0; vi < DUST_N_PARTICLES; vi++)
    {
        vertices[vi].x = (ranrot_rand() % DUST_SCALE) - DUST_SCALE / 2;
        vertices[vi].y = (ranrot_rand() % DUST_SCALE) - DUST_SCALE / 2;
        vertices[vi].z = (ranrot_rand() % DUST_SCALE) - DUST_SCALE / 2;
        
        // Set up element index array for warp mode.
        indices[vi * 2] = vi;
        indices[vi * 2 + 1] = vi + DUST_N_PARTICLES;
        
#if OO_SHADERS
        vertices[vi + DUST_N_PARTICLES] = vertices[vi];
        warpinessAttr[vi] = 0.0f;
        warpinessAttr[vi + DUST_N_PARTICLES] = 1.0f;
#endif
    }
    
#if OO_SHADERS
    shaderMode = kShaderModeUnknown;
#endif
    
    dust_color = [[OOColor colorWithRed:0.5 green:1.0 blue:1.0 alpha:1.0] retain];
    [self setStatus:STATUS_ACTIVE];
 
    hasPointSprites = [[OOOpenGLExtensionManager sharedManager] haveExtension:@"GL_ARB_point_sprite"];
    
    if (hasPointSprites)
    {
        texture = [[OOTexture textureWithName:@"oolite-particle-dust.png"
                                                                 inFolder:@"Textures"
                                                                    options:kOOTextureMinFilterMipMap | kOOTextureMagFilterLinear | kOOTextureAlphaMask
                                                             anisotropy:kOOTextureDefaultAnisotropy / 2.0
                                                                    lodBias:0.0] retain];
    }   
 
    collision_radius = DUST_SCALE; // for draw pass calculations
 
    [[OOGraphicsResetManager sharedManager] registerClient:self];
 
    return self;
}
 
 
- (void) dealloc
{
    DESTROY(dust_color);
    [[OOGraphicsResetManager sharedManager] unregisterClient:self];
 
    DESTROY(texture);
#if OO_SHADERS
    DESTROY(shader);
    DESTROY(uniforms);
#endif
    
    [super dealloc];
}
 
 
- (void) setDustColor:(OOColor *) color
{
    if (dust_color) [dust_color release];
    dust_color = [color retain];
    [dust_color getRed:&color_fv[0] green:&color_fv[1] blue:&color_fv[2] alpha:&color_fv[3]];
}
 
 
- (OOColor *) dustColor
{
    return dust_color;
}
 
 
- (BOOL) canCollide
{
    return NO;
}
 
 
- (void) updateCameraRelativePosition
{
    HPVector c_pos = [PLAYER viewpointPosition];
    cameraRelativePosition = make_vector((OOScalar)-fmod(c_pos.x,DUST_SCALE),(OOScalar)-fmod(c_pos.y,DUST_SCALE),(OOScalar)-fmod(c_pos.z,DUST_SCALE));
}
 
 
- (void) update:(OOTimeDelta) delta_t
{
    // [self setPosition:position];
    zero_distance = 0.0;
            
#if OO_SHADERS
    if (EXPECT_NOT(shaderMode == kShaderModeUnknown))  [self checkShaderMode];
    
    // Shader takes care of repositioning.
    if (shaderMode == kShaderModeOn)  return;
#endif
    
    Vector offset = vector_flip(cameraRelativePosition);
    GLfloat  half_scale = DUST_SCALE * 0.50;
    int vi;
    for (vi = 0; vi < DUST_N_PARTICLES; vi++)
    {
        while (vertices[vi].x - offset.x < -half_scale)
            vertices[vi].x += DUST_SCALE;
        while (vertices[vi].x - offset.x > half_scale)
            vertices[vi].x -= DUST_SCALE;
        
        while (vertices[vi].y - offset.y < -half_scale)
            vertices[vi].y += DUST_SCALE;
        while (vertices[vi].y - offset.y > half_scale)
            vertices[vi].y -= DUST_SCALE;
        
        while (vertices[vi].z - offset.z < -half_scale)
            vertices[vi].z += DUST_SCALE;
        while (vertices[vi].z - offset.z > half_scale)
            vertices[vi].z -= DUST_SCALE;
    }
}
 
 
#if OO_SHADERS
- (OOShaderProgram *) shader
{
    if (shader == nil)
    {
        NSString *prefix = [NSString stringWithFormat:
                           @"#define OODUST_SCALE_MAX    (float(%g))\n"
                            "#define OODUST_SCALE_FACTOR (float(%g))\n"
                            "#define OODUST_SIZE         (float(%g))\n",
                            FAR_PLANE / NEAR_PLANE,
                            1.0f / (FAR_PLANE - NEAR_PLANE),
                            (float)DUST_SCALE];
        
        // Reuse tangent attribute ID for "warpiness", as we don't need a tangent.
        NSDictionary *attributes = [NSDictionary dictionaryWithObject:[NSNumber numberWithInt:kTangentAttributeIndex]
                                                               forKey:@"aWarpiness"];
        
        shader = [[OOShaderProgram shaderProgramWithVertexShaderName:@"oolite-dust.vertex"
                                                  fragmentShaderName:@"oolite-dust.fragment"
                                                              prefix:prefix
                                                   attributeBindings:attributes] retain];
        
        DESTROY(uniforms);
        OOShaderUniform *uWarp = [[OOShaderUniform alloc] initWithName:@"uWarp"
                                                         shaderProgram:shader
                                                         boundToObject:self
                                                              property:@selector(warpVector)
                                                        convertOptions:0];
        OOShaderUniform *uOffsetPlayerPosition = [[OOShaderUniform alloc] initWithName:@"uOffsetPlayerPosition"
                                                                   shaderProgram:shader
                                                                   boundToObject:self
                                                                        property:@selector(offsetPlayerPosition)
                                                                  convertOptions:0];
        
        uniforms = [[NSArray alloc] initWithObjects:uWarp, uOffsetPlayerPosition, nil];
        [uWarp release];
        [uOffsetPlayerPosition release];
    }
    
    return shader;
}
 
- (Vector) offsetPlayerPosition
{
    // used as shader uniform, so needs to be low precision
    HPVector c_pos = [PLAYER viewpointPosition];
    Vector offset = make_vector((OOScalar)fmod(c_pos.x,DUST_SCALE),(OOScalar)fmod(c_pos.y,DUST_SCALE),(OOScalar)fmod(c_pos.z,DUST_SCALE));
    return vector_subtract(offset, make_vector(DUST_SCALE * 0.5f, DUST_SCALE * 0.5f, DUST_SCALE * 0.5f));
}
 
 
- (void) checkShaderMode
{
    shaderMode = kShaderModeOff;
    if ([UNIVERSE detailLevel] >= DETAIL_LEVEL_SHADERS)
    {
        if ([[OOOpenGLExtensionManager sharedManager] useDustShader])
        {
            shaderMode = kShaderModeOn;
        }
    }
}
#endif
 
 
- (Vector) warpVector
{
    return vector_multiply_scalar([PLAYER velocity], 1.0f / HYPERSPEED_FACTOR);
}
 
 
- (void) drawImmediate:(bool)immediate translucent:(bool)translucent
{
    if ([UNIVERSE breakPatternHide] || !translucent)  return;   // DON'T DRAW
    
    PlayerEntity* player = PLAYER;
    assert(player != nil);
    
#ifndef NDEBUG
    if (gDebugFlags & DEBUG_NO_DUST)  return;
#endif
    
#if OO_SHADERS
    if (EXPECT_NOT(shaderMode == kShaderModeUnknown))  [self checkShaderMode];
    BOOL useShader = (shaderMode == kShaderModeOn);
#endif
    
 
    GLfloat *fogcolor = [UNIVERSE skyClearColor];
    float   idealDustSize = [[UNIVERSE gameView] viewSize].width / 800.0f;
    
    BOOL    warp_stars = [player atHyperspeed];
    float   dustIntensity;
    
    OO_ENTER_OPENGL();
    OOSetOpenGLState(OPENGL_STATE_OPAQUE);
    OOGL(glDisableClientState(GL_NORMAL_ARRAY));
 
    if (!warp_stars)
    {
        // Draw points.
        float dustPointSize = ceil(idealDustSize);
        if (dustPointSize < 1.0f)  dustPointSize = 1.0f;
        OOGL(GLScaledPointSize(dustPointSize));
        dustIntensity = OOClamp_0_1_f(idealDustSize / dustPointSize);
    }
    else
    {
        // Draw lines.
        float idealLineSize = idealDustSize * 0.5f;
        float dustLineSize = ceil(idealLineSize);
        if (dustLineSize < 1.0f)  dustLineSize = 1.0f;
        GLScaledLineWidth(dustLineSize);
        dustIntensity = OOClamp_0_1_f(idealLineSize / dustLineSize);
    }
    if (fogcolor[3] > 0.0)
    {
        // fade out dust when entering atmosphere (issue #100)
        dustIntensity = OOClamp_0_1_f(dustIntensity-(fogcolor[3]*3.0));
    }
 
 
    if (dustIntensity > 0.0)
    {
 
        float   *color = NULL;
        if (player->isSunlit)  color = color_fv;
        else  color = UNIVERSE->stars_ambient;
        OOGL(glColor4f(color[0], color[1], color[2], dustIntensity));
    
#if OO_SHADERS
        if (useShader)
        {
            [[self shader] apply];
            [uniforms makeObjectsPerformSelector:@selector(apply)];
        }
        else
#endif
        {
            OOGL(glEnable(GL_FOG));
            OOGL(glFogi(GL_FOG_MODE, GL_LINEAR));
            OOGL(glFogfv(GL_FOG_COLOR, fogcolor));
            OOGL(glHint(GL_FOG_HINT, GL_NICEST));
            OOGL(glFogf(GL_FOG_START, NEAR_PLANE));
            OOGL(glFogf(GL_FOG_END, FAR_PLANE));
        }
 
        OOGL(glEnable(GL_BLEND));
        OOGL(glDepthMask(GL_FALSE));
    
        if (warp_stars)
        {
            OOGL(glDisable(GL_TEXTURE_2D));
#if OO_SHADERS
            if (useShader)
            {
                OOGL(glEnableVertexAttribArrayARB(kTangentAttributeIndex));
                OOGL(glVertexAttribPointerARB(kTangentAttributeIndex, 1, GL_FLOAT, GL_FALSE, 0, warpinessAttr));
            }
            else
#endif
            {
                Vector  warpVector = [self warpVector];
                unsigned vi;
                for (vi = 0; vi < DUST_N_PARTICLES; vi++)
                {
                    vertices[vi + DUST_N_PARTICLES] = vector_subtract(vertices[vi], warpVector);
                }
            }
        
            OOGL(glVertexPointer(3, GL_FLOAT, 0, vertices));
            OOGL(glDrawElements(GL_LINES, DUST_N_PARTICLES * 2, GL_UNSIGNED_SHORT, indices));
        
#if OO_SHADERS
            if (useShader)
            {
                OOGL(glDisableVertexAttribArrayARB(kTangentAttributeIndex));
            }
#endif
            OOGL(glEnable(GL_TEXTURE_2D));
    
        }
        else
        {
            if (hasPointSprites)
            {
#if OO_SHADERS
                if (!useShader)
#endif
                {
                    OOGL(glBlendFunc(GL_SRC_ALPHA, GL_ONE));
                }
                OOGL(glEnable(GL_POINT_SPRITE_ARB));
                [texture apply];
                OOGL(glVertexPointer(3, GL_FLOAT, 0, vertices));
                OOGL(glDrawArrays(GL_POINTS, 0, DUST_N_PARTICLES));
                OOGL(glDisable(GL_POINT_SPRITE_ARB));
            }
            else
            {
                OOGL(glDisable(GL_TEXTURE_2D));
                OOGL(glVertexPointer(3, GL_FLOAT, 0, vertices));
                OOGL(glDrawArrays(GL_POINTS, 0, DUST_N_PARTICLES));
                OOGL(glEnable(GL_TEXTURE_2D));
            }
        }
    
        // reapply normal conditions
#if OO_SHADERS
        if (useShader)
        {
            [OOShaderProgram applyNone];
        }
        else
#endif
        {
            OOGL(glDisable(GL_FOG));
            OOGL(glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA));
        }
    
        OOGL(glDisable(GL_BLEND));
        OOGL(glDepthMask(GL_TRUE));
 
    }
    OOGL(glEnableClientState(GL_NORMAL_ARRAY));
    
    OOVerifyOpenGLState();
    OOCheckOpenGLErrors(@"DustEntity after drawing %@", self);
}
 
 
- (void) resetGraphicsState
{
#if OO_SHADERS
    DESTROY(shader);
    DESTROY(uniforms);
    
    shaderMode = kShaderModeUnknown;
    
    /*  Duplicate vertex data. This is only required if we're switching from
        non-shader mode to a shader mode, but let's KISS.
    */
    memcpy(vertices + DUST_N_PARTICLES, vertices, sizeof *vertices * DUST_N_PARTICLES);
#endif
}
 
 
#ifndef NDEBUG
- (NSString *) descriptionForObjDump
{
    // Don't include range and visibility flag as they're irrelevant.
    return [self descriptionForObjDumpBasic];
}
#endif
 
@end