Custom shaders during a shadow pass.

[NickHardeman]

This allows using custom shaders during a shadow pass. The materials do not support custom shadow passes yet. Maybe that can be addressed in the next minor release. I tested using the shadow and material examples but could probably use a bit more.

Shadow shader functions have been added, so you can setup a shader using a function within the shadow class
shadow.setupShadowDepthShader(ofShader& ashader, const std::string aShaderMain);

The shader function for sending to the frag shader accepts a world position

vec3 worldPosition = (modelMatrix * vec4(position.xyz, 1.0)).xyz;
sendShadowDepthWorldPosition(worldPosition);

An example vert shader based on the MaterialPBRAdvanced Example

#if defined(SHADOW_DEPTH_PASS)
uniform mat4 modelMatrix;
in vec4 position;
uniform float iElapsedTime;
#else
OUT vec3 v_localPos;
#endif

void main (void){
	vec4 npos = position;
	npos.xyz += 3.0 * vec3( cos(iElapsedTime+position.y*1.25), 0.0, 0.0);
#if defined(SHADOW_DEPTH_PASS)
	vec3 worldPosition = (modelMatrix * vec4(npos.xyz, 1.0)).xyz;
	sendShadowDepthWorldPosition(worldPosition);
#else
	v_localPos = position.xyz;
	sendVaryings(npos);
	gl_Position = modelViewProjectionMatrix * npos;
#endif
	
}

Example usage:

if( light.shouldRenderShadowDepthPass() ) {
	int numShadowPasses = light.getNumShadowDepthPasses();
	light.beginShadowDepthPass();
	mDepthShader.begin();
	mDepthShader.setUniform1f("iElapsedTime", ofGetElapsedTimef());
	renderScene(true);
	mDepthShader.end();
	light.endShadowDepthPass();
}

[NickHardeman]

Addresses issue #7555

[ofTheo]

the broken arm check is fixed now in apothecary will re-run in a sec to confirm