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Finalize ParticleSystemTransformFeedback sample.
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@danginsburg
danginsburg committed Sep 13, 2013
1 parent f56b33a commit ab36548
Showing 1 changed file with 15 additions and 15 deletions.
30 changes: 15 additions & 15 deletions Chapter_14/ParticleSystemTransformFeedback/ParticleSystemTransformFeedback.c
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Original file line number Diff line number Diff line change
Expand Up @@ -19,9 +19,9 @@
#include "esUtil.h"
#include "Noise3D.h"

#define NUM_PARTICLES 500
#define NUM_PARTICLES 200
#define EMISSION_RATE 0.3f
#define ACCELERATION -9.8f // Gravity
#define ACCELERATION -1.0f

#define ATTRIBUTE_POSITION 0
#define ATTRIBUTE_VELOCITY 1
Expand Down Expand Up @@ -110,7 +110,7 @@ void InitEmitParticles ( ESContext *esContext )

char vShaderStr[] =
"#version 300 es \n"
"#define NUM_PARTICLES 500.0 \n"
"#define NUM_PARTICLES 200 \n"
"#define ATTRIBUTE_POSITION 0 \n"
"#define ATTRIBUTE_VELOCITY 1 \n"
"#define ATTRIBUTE_SIZE 2 \n"
Expand All @@ -134,20 +134,21 @@ void InitEmitParticles ( ESContext *esContext )
" \n"
"float randomValue( inout float seed ) \n"
"{ \n"
" float vertexId = float( gl_VertexID ) / NUM_PARTICLES; \n"
" float vertexId = float( gl_VertexID ) / float( NUM_PARTICLES ); \n"
" vec3 texCoord = vec3( u_time, vertexId, seed ); \n"
" seed += 0.1; \n"
" return texture( s_noiseTex, texCoord ).r; \n"
"} \n"
"void main() \n"
"{ \n"
" float seed = u_time; \n"
" if( randomValue(seed) < u_emissionRate ) \n"
" float lifetime = a_curtime - u_time; \n"
" if( lifetime <= 0.0 && randomValue(seed) < u_emissionRate ) \n"
" { \n"
" v_position = vec2( randomValue(seed) * 0.1 - 0.05, -1.0 ); \n"
" v_velocity = vec2( randomValue(seed) * 2.0 - 1.0, \n"
" randomValue(seed) * 4.0 + 4.0 ); \n"
" v_size = randomValue(seed) * 2.5 + 20.0; \n"
" v_position = vec2( 0.0, -1.0 ); \n"
" v_velocity = vec2( randomValue(seed) * 2.0 - 1.00, \n"
" randomValue(seed) * 0.4 + 2.0 ); \n"
" v_size = randomValue(seed) * 20.0 + 60.0; \n"
" v_curtime = u_time; \n"
" v_lifetime = 2.0; \n"
" } \n"
Expand Down Expand Up @@ -231,7 +232,7 @@ int Init ( ESContext *esContext )
" vec2 velocity = a_velocity + deltaTime * u_acceleration; \n"
" vec2 position = a_position + deltaTime * velocity; \n"
" gl_Position = vec4( position, 0.0, 1.0 ); \n"
" gl_PointSize = a_size; \n"
" gl_PointSize = a_size * ( 1.0 - deltaTime / a_lifetime ); \n"
" } \n"
" else \n"
" { \n"
Expand Down Expand Up @@ -346,14 +347,14 @@ void EmitParticles ( ESContext *esContext, float deltaTime )
// Set transform feedback buffer
glBindBufferBase( GL_TRANSFORM_FEEDBACK_BUFFER, 0, dstVBO );

// Turn off rasterization -we are not drawing
// Turn off rasterization - we are not drawing
glEnable( GL_RASTERIZER_DISCARD );

// Set uniforms
glUniform1f( userData->emitTimeLoc, userData->time );
glUniform1f( userData->emitEmissionRateLoc, EMISSION_RATE );

// Bind the 3D nosei texture
// Bind the 3D noise texture
glActiveTexture( GL_TEXTURE0 );
glBindTexture( GL_TEXTURE_3D, userData->noiseTextureId );
glUniform1i( userData->emitNoiseSamplerLoc, 0 );
Expand All @@ -363,11 +364,10 @@ void EmitParticles ( ESContext *esContext, float deltaTime )
glDrawArrays( GL_POINTS, 0, NUM_PARTICLES );
glEndTransformFeedback();

// Restore state
glDisable( GL_RASTERIZER_DISCARD );
glUseProgram ( 0 );

glBindBufferBase ( GL_TRANSFORM_FEEDBACK_BUFFER, 0, 0 );

glBindTexture( GL_TEXTURE_3D, 0 );

// Ping pong the buffers
Expand Down Expand Up @@ -408,7 +408,7 @@ void Draw ( ESContext *esContext )

// Set uniforms
glUniform1f( userData->drawTimeLoc, userData->time );
glUniform4f( userData->drawColorLoc, 1.0f, 0.25f, 0.0f, 1.0f );
glUniform4f( userData->drawColorLoc, 1.0f, 1.0f, 1.0f, 1.0f );
glUniform2f( userData->drawAccelerationLoc, 0.0f, ACCELERATION );

// Blend particles
Expand Down

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