Sure.The code uses a fixed array of sprites and draws them in sequence. I'm not sorting them based on texture yet, but the performance on the xperia isn't great when just one texture is used. I'm wondering if set texture or set uniform value is an expensive operation I should only call infrequently (eg by sorting sprites based on texture into buckets)
// loop called every frame
// setup
graphics.SetShaderProgram( shader_program );
graphics.Enable( EnableMode.Blend );
graphics.SetBlendFunc( BlendFuncMode.Add, BlendFuncFactor.SrcAlpha, BlendFuncFactor.OneMinusSrcAlpha );
graphics.SetBlendFuncAlpha( BlendFuncMode.Add, BlendFuncFactor.SrcAlpha, BlendFuncFactor.OneMinusSrcAlpha );
// draw specific sprites
for( int loop = 0; loop < MAX_SPRITES; loop++ )
{
if( sprites[loop].active )
{
#region animation
switch( sprites[loop].anim_type )
{
case ANIM_INCREASE:
sprites[loop].frame+=sprites[loop].anim_amount;//*time_scale;
if( sprites[loop].frame >= sprites[loop].anim_max )
sprites[loop].frame = sprites[loop].frame - sprites[loop].anim_max;
break;
// other anim types snipped
case ANIM_NONE:
texcoords[0] = 0;
texcoords[1] = 0;
texcoords[2] = 0;
texcoords[3] = 1;
texcoords[4] = 1;
texcoords[5] = 0;
texcoords[6] = 1;
texcoords[7] = 1;
vertex_buffer.SetVertices( 1, texcoords );
break;
}
if( sprites[loop].anim_type != ANIM_NONE )
{
int span = sprite_info[sprites[loop].graphic].width/sprite_info[sprites[loop].graphic].draw_width;
float height = sprite_info[sprites[loop].graphic].height/sprite_info[sprites[loop].graphic].draw_height;
int dx,dy;
dx = (int)(sprites[loop].frame) % span;
dy = (int)(sprites[loop].frame) / span;
texcoords[0] = (float)dx/(float)span;
texcoords[1] = (float)dy/(float)height;
texcoords[2] = (float)dx/(float)span;
texcoords[3] = ((float)dy+1.0f)/height;
texcoords[4] = (float)(dx+1.0f)/(float)span;
texcoords[5] = (float)dy/(float)height;
texcoords[6] = (float)(dx+1.0f)/(float)span;
texcoords[7] = ((float)dy+1.0f)/height;
vertex_buffer.SetVertices( 1, texcoords );
}
#endregion
// texture
shader_program.SetUniformValue( 0, ref sprites[loop].trans_matrix );
graphics.SetTexture( 0, textures[ sprites[loop].graphic ] );
// colour region snipped for brevity
#region position and rotation
x = (sprites[loop].x*x_scaler) - ( (sprites[loop].width*sprites[loop].scale) / 2.0f );
y = (sprites[loop].y*y_scaler) - ( (sprites[loop].height*sprites[loop].scale) / 2.0f );
// get positions of all verteces. vertexes? virtices? corners. Get all four corners.
centre_x = (sprites[loop].x*x_scaler)/128.0f;
centre_y = (sprites[loop].y*y_scaler)/128.0f;
x1 = x / 128.0f;
y1 = y / 128.0f;
x2 = x / 128.0f;
y2 = (y / 128.0f) + ((sprites[loop].height*sprites[loop].scale)/128.0f);
x3 = (x / 128.0f) + ((sprites[loop].width*sprites[loop].scale)/128.0f);
y3 = y / 128.0f;
x4 = (x / 128.0f) + ((sprites[loop].width*sprites[loop].scale)/128.0f);
y4 = (y / 128.0f) + ((sprites[loop].height*sprites[loop].scale)/128.0f);
// rotate sprite if necessary. TODO: switch to matrix
if( sprites[loop].rotation != 0 )
{
Rotate_Point(ref x1, ref y1,centre_x, centre_y, sprites[loop].rotation);
Rotate_Point(ref x2, ref y2,centre_x, centre_y, sprites[loop].rotation);
Rotate_Point(ref x3, ref y3,centre_x, centre_y, sprites[loop].rotation);
Rotate_Point(ref x4, ref y4,centre_x, centre_y, sprites[loop].rotation);
}
// now set the vert.. corners.
vertices[0] = x1;
vertices[1] = y1;
vertices[2] = sprites[loop].z;
vertices[3] = x2;
vertices[4] = y2;
vertices[5] = sprites[loop].z;
vertices[6] = x3;
vertices[7] = y3;
vertices[8] = sprites[loop].z;
vertices[9] = x4;
vertices[10] = y4;
vertices[11] = sprites[loop].z;
vertex_buffer.SetVertices( 0, vertices );
#endregion
// draw
graphics.SetVertexBuffer( 0, vertex_buffer );
graphics.DrawArrays( DrawMode.TriangleStrip, 0, index_size );
}
}
Thanks for taking the time to look at this
Cheers,
Robin.
