Draw on buffer to apply to sprite

[Rick]

Rephrasing the question: How can I make the texture background transparent so the only thing I see is my text?

 

    local shader = Shader:Load("Shaders/model/diffuse.shader")
    local currentBuff = Buffer:GetCurrent()
    local mat = Material:Create()
    mat:SetShader(shader)
    local sprite = Sprite:Create()
    sprite:SetViewMode(0)
    sprite:SetMaterial(mat)
    local buffer = Buffer:Create(20, 20, 1, 1)
    
    -- draw the text on the buffer
    Buffer:SetCurrent(buffer)
    self.context:SetBlendMode(Blend.Alpha)
    self.context:SetColor(Vec4(1, 0, 0, 1))
    self.context:DrawText("Hello", 0, 0)
    local tex = buffer:GetColorTexture(0)
    mat:SetTexture(tex, 0)
    Buffer:SetCurrent(currentBuff)

 

[Ma-Shell]

The shader is the problem. Use "Shaders/model/diffuse+normal+alphamask.shader" instead of "diffuse.shader", then it should work.

[Rick]

So that kind of works. I see only the text but even though I changed color to red the text is black and can't really see it because of that.

[Ma-Shell]

For me the text is red (given, it's a very dark red...). You should be able to make it more visible by using "diffuse+normal+emission+alphamask.shader" and binding the texture to both, channels 0 (diffuse) and 4 (emission):

i.e.:

    local shader = Shader:Load("Shaders/model/diffuse+normal+emission+alphamask.shader")
    local currentBuff = Buffer:GetCurrent()
    local mat = Material:Create()
    mat:SetShader(shader)
    local sprite = Sprite:Create()
    sprite:SetViewMode(0)
    sprite:SetMaterial(mat)
    local buffer = Buffer:Create(20, 20, 1, 1)
    
    -- draw the text on the buffer
    Buffer:SetCurrent(buffer)
    self.context:SetBlendMode(Blend.Alpha)
    self.context:SetColor(Vec4(1, 0, 0, 1))
    self.context:DrawText("Hello", 0, 0)
    local tex = buffer:GetColorTexture(0)
    mat:SetTexture(tex, 0)
    mat:SetTexture(tex, 4)
    Buffer:SetCurrent(currentBuff)

That should make it more crisp.

[Rick]

That worked thank you much.

Any ideas on how to fade out the text? I can change the alpha of SetColor() but currently I clear the buffer but that results in a white buffer it seems as the sprite goes all white when I call buffer:Clear(). It's like I need to clear it with no color. Currently I call Clear() then SetColor() where the alpha is going down from 1 to 0 and redrawing the text. However, as stated all I see is white.