Пример #1
0
// generateMipmaps will generate mipmaps for the gl texture
func (texture *Texture) generateMipmaps() {
	// The GL_GENERATE_MIPMAP texparameter is set in loadVolatile if we don't
	// have support for glGenerateMipmap.
	if texture.mipmaps {
		// Driver bug: http://www.opengl.org/wiki/Common_Mistakes#Automatic_mipmap_generation
		if runtime.GOOS == "windows" || runtime.GOOS == "linux" {
			gl.Enable(gl.TEXTURE_2D)
		}

		gl.GenerateMipmap(gl.TEXTURE_2D)
	}
}
Пример #2
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// StencilExt operates like stencil but with access to change the stencil action,
// value, and keepvalues.
//
// action: How to modify any stencil values of pixels that are touched by what's
// drawn in the stencil function.
//
// value: The new stencil value to use for pixels if the "replace" stencil action
// is used. Has no effect with other stencil actions. Must be between 0 and 255.
//
// keepvalues: True to preserve old stencil values of pixels, false to re-set
// every pixel's stencil value to 0 before executing the stencil function. Clear
// will also re-set all stencil values.
func StencilExt(stencil_func func(), action StencilAction, value int32, keepvalues bool) {
	gl_state.writingToStencil = true
	if !keepvalues {
		gl.Clear(gl.STENCIL_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
	}
	if gl_state.currentCanvas != nil {
		gl_state.currentCanvas.checkCreateStencil()
	}
	gl.Enable(gl.STENCIL_TEST)
	gl.ColorMask(false, false, false, false)
	gl.StencilFunc(gl.ALWAYS, int(value), 0xFF)
	gl.StencilOp(gl.KEEP, gl.KEEP, gl.Enum(action))

	stencil_func()

	gl_state.writingToStencil = false
	SetColorMask(states.back().colorMask)
	SetStencilTest(states.back().stencilCompare, states.back().stencilTestValue)
}
Пример #3
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// SetStencilTest configures or disables stencil testing. When stencil testing is
// enabled, the geometry of everything that is drawn afterward will be clipped/stencilled
// out based on a comparison between the arguments of this function and the stencil
// value of each pixel that the geometry touches. The stencil values of pixels are
// affected via Stencil/StencilEXT.
func SetStencilTest(compare CompareMode, value int32) {
	if gl_state.writingToStencil {
		return
	}

	states.back().stencilCompare = compare
	states.back().stencilTestValue = value
	if compare == COMPARE_ALWAYS {
		gl.Disable(gl.STENCIL_TEST)
		return
	}

	if gl_state.currentCanvas != nil {
		gl_state.currentCanvas.checkCreateStencil()
	}

	gl.Enable(gl.STENCIL_TEST)
	gl.StencilFunc(gl.Enum(compare), int(value), 0xFF)
	gl.StencilOp(gl.KEEP, gl.KEEP, gl.REPLACE)
}
Пример #4
0
// SetScissor Sets or disables scissor. The scissor limits the drawing area to a
// specified rectangle. This affects all graphics calls, including Clear.  The
// dimensions of the scissor is unaffected by graphical transformations
// (translate, scale, ...). if no arguments are given it will disable the scissor.
// if x, y, w, h are given it will enable the scissor
func SetScissor(args ...int32) {
	if args == nil {
		gl.Disable(gl.SCISSOR_TEST)
		states.back().scissor = false
	} else if len(args) == 4 {
		x, y, width, height := args[0], args[1], args[2], args[3]
		gl.Enable(gl.SCISSOR_TEST)
		if gl_state.currentCanvas != nil {
			gl.Scissor(x, y, width, height)
		} else {
			// With no Canvas active, we need to compensate for glScissor starting
			// from the lower left of the viewport instead of the top left.
			gl.Scissor(x, gl_state.viewport[3]-(y+height), width, height)
		}
		states.back().scissorBox = []int32{x, y, width, height}
		states.back().scissor = true
	} else {
		panic("incorrect number of arguments to setscissor")
	}
}
Пример #5
0
// InitContext will initiate the opengl context with a viewport in the size of
// w x h. This is generally called from the game loop and wont generally need to
// be called unless you are rolling your own game loop.
func InitContext(w, h int32) {
	if gl_state.initialized {
		return
	}

	// Okay, setup OpenGL.
	gl.ContextWatcher.OnMakeCurrent(nil)

	//Get system info
	opengl_version = gl.GetString(gl.VERSION)
	opengl_vendor = gl.GetString(gl.VENDOR)
	gl_state.defaultFBO = gl.GetBoundFramebuffer()
	gl.GetIntegerv(gl.VIEWPORT, gl_state.viewport)
	// And the current scissor - but we need to compensate for GL scissors
	// starting at the bottom left instead of top left.
	gl.GetIntegerv(gl.SCISSOR_BOX, states.back().scissorBox)
	states.back().scissorBox[1] = gl_state.viewport[3] - (states.back().scissorBox[1] + states.back().scissorBox[3])

	initMaxValues() //check shim code

	glcolor := []float32{1.0, 1.0, 1.0, 1.0}
	gl.VertexAttrib4fv(attrib_color, glcolor)
	gl.VertexAttrib4fv(attrib_constantcolor, glcolor)
	useVertexAttribArrays(0)

	// Enable blending
	gl.Enable(gl.BLEND)
	SetBlendMode(BLENDMODE_ALPHA)
	// Auto-generated mipmaps should be the best quality possible
	gl.Hint(gl.GENERATE_MIPMAP_HINT, gl.NICEST)
	// Make sure antialiasing works when set elsewhere
	enableMultisample() //check shim code
	// Set pixel row alignment
	gl.PixelStorei(gl.UNPACK_ALIGNMENT, 1)

	//default matricies
	gl_state.projectionStack = matstack.NewMatStack()
	gl_state.viewStack = matstack.NewMatStack() //stacks are initialized with ident matricies on top

	SetViewportSize(w, h)
	SetBackgroundColor(0, 0, 0, 255)

	gl_state.boundTextures = make([]gl.Texture, maxTextureUnits)
	curgltextureunit := gl.GetInteger(gl.ACTIVE_TEXTURE)
	gl_state.curTextureUnit = int(curgltextureunit - gl.TEXTURE0)
	// Retrieve currently bound textures for each texture unit.
	for i := 0; i < len(gl_state.boundTextures); i++ {
		gl.ActiveTexture(gl.Enum(gl.TEXTURE0 + uint32(i)))
		gl_state.boundTextures[i] = gl.Texture{Value: uint32(gl.GetInteger(gl.TEXTURE_BINDING_2D))}
	}
	gl.ActiveTexture(gl.Enum(curgltextureunit))
	createDefaultTexture()
	setTextureUnit(0)

	// We always need a default shader.
	defaultShader = NewShader()

	gl_state.initialized = true

	loadAllVolatile()

	//have to set this after loadallvolatile() so we are sure the  default shader is loaded
	SetShader(nil)
}