Example #1
0
func initialize(c *opengl.Context) error {
	shaderVertexModelviewNative, err := c.NewShader(c.VertexShader, shader(c, shaderVertexModelview))
	if err != nil {
		return err
	}
	defer c.DeleteShader(shaderVertexModelviewNative)

	shaderVertexColorNative, err := c.NewShader(c.VertexShader, shader(c, shaderVertexColor))
	if err != nil {
		return err
	}
	defer c.DeleteShader(shaderVertexColorNative)

	shaderVertexColorLineNative, err := c.NewShader(c.VertexShader, shader(c, shaderVertexColorLine))
	if err != nil {
		return err
	}
	defer c.DeleteShader(shaderVertexColorLineNative)

	shaderFragmentTextureNative, err := c.NewShader(c.FragmentShader, shader(c, shaderFragmentTexture))
	if err != nil {
		return err
	}
	defer c.DeleteShader(shaderFragmentTextureNative)

	shaderFragmentSolidNative, err := c.NewShader(c.FragmentShader, shader(c, shaderFragmentSolid))
	if err != nil {
		return err
	}
	defer c.DeleteShader(shaderFragmentSolidNative)

	programTexture, err = c.NewProgram([]opengl.Shader{
		shaderVertexModelviewNative,
		shaderFragmentTextureNative,
	})
	if err != nil {
		return err
	}

	programSolidRect, err = c.NewProgram([]opengl.Shader{
		shaderVertexColorNative,
		shaderFragmentSolidNative,
	})
	if err != nil {
		return err
	}

	programSolidLine, err = c.NewProgram([]opengl.Shader{
		shaderVertexColorLineNative,
		shaderFragmentSolidNative,
	})
	if err != nil {
		return err
	}

	// 16 [bytse] is an arbitrary number which seems enough to draw anything. Fix this if necessary.
	const stride = 16
	c.NewBuffer(c.ArrayBuffer, 4*stride*quadsMaxNum, c.DynamicDraw)

	indices := make([]uint16, 6*quadsMaxNum)
	for i := uint16(0); i < quadsMaxNum; i++ {
		indices[6*i+0] = 4*i + 0
		indices[6*i+1] = 4*i + 1
		indices[6*i+2] = 4*i + 2
		indices[6*i+3] = 4*i + 1
		indices[6*i+4] = 4*i + 2
		indices[6*i+5] = 4*i + 3
	}
	indexBufferQuads = c.NewBuffer(c.ElementArrayBuffer, indices, c.StaticDraw)

	indices = make([]uint16, indicesNum)
	for i := 0; i < len(indices); i++ {
		indices[i] = uint16(i)
	}
	indexBufferLines = c.NewBuffer(c.ElementArrayBuffer, indices, c.StaticDraw)

	return nil
}