// Here goes our drawing code
func drawGLScene(sector Sector) {
xtrans := gl.GLfloat(-xpos)
ztrans := gl.GLfloat(-zpos)
ytrans := gl.GLfloat(-walkbias - 0.25)
scenroty := gl.GLfloat(360.0 - yrot)
// Clear the screen and depth buffer
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
// reset the view
gl.LoadIdentity()
// Rotate up and down to look up and down
gl.Rotatef(float32(lookupdown), 1.0, 0.0, 0.0)
// Rotate depending on direction player is facing
gl.Rotatef(float32(scenroty), 0.0, 1.0, 0.0)
// translate the scene based on player position
gl.Translatef(float32(xtrans), float32(ytrans), float32(ztrans))
gl.BindTexture(gl.TEXTURE_2D, uint(textures[filter]))
for _, vertices := range sector {
gl.Begin(gl.TRIANGLES)
for _, triangle := range *vertices {
gl.Normal3f(0.0, 0.0, 1.0)
gl.TexCoord2f(float32(triangle.u), float32(triangle.v))
gl.Vertex3f(float32(triangle.x), float32(triangle.y), float32(triangle.z))
}
gl.End()
}
// Draw to the screen
sdl.GL_SwapBuffers()
// Gather our frames per second
frames++
t := sdl.GetTicks()
if t-t0 >= 5000 {
seconds := (t - t0) / 1000.0
fps := frames / seconds
fmt.Println(frames, "frames in", seconds, "seconds =", fps, "FPS")
t0 = t
frames = 0
}
}
// Here goes our drawing code
func drawGLScene() {
// Clear the screen and depth buffer
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
// Move left 1.5 units and into the screen 6.0 units.
gl.LoadIdentity()
gl.Translatef(0.0, 0.0, float32(z)) // translate by z
gl.Rotatef(float32(xrot), 1.0, 0.0, 0.0) /* Rotate On The X Axis */
gl.Rotatef(float32(yrot), 0.0, 1.0, 0.0) /* Rotate On The Y Axis */
/* Select Our Texture */
gl.BindTexture(gl.TEXTURE_2D, uint(textures[filter])) // based on filter
gl.Begin(gl.QUADS)
// Front face
gl.Normal3f(0.0, 0.0, 1.0) // Normal Pointing Towards Viewer
gl.TexCoord2f(0.0, 1.0); gl.Vertex3f(-1.0, -1.0, 1.0) // Bottom left
gl.TexCoord2f(1.0, 1.0); gl.Vertex3f( 1.0, -1.0, 1.0) // Bottom right
gl.TexCoord2f(1.0, 0.0); gl.Vertex3f( 1.0, 1.0, 1.0) // Top right
gl.TexCoord2f(0.0, 0.0); gl.Vertex3f(-1.0, 1.0, 1.0) // Top left
// Back Face
gl.Normal3f(0.0, 0.0, -1.0) // Normal Pointing Away From Viewer
gl.TexCoord2f(0.0, 0.0); gl.Vertex3f(-1.0, -1.0, -1.0) // Bottom right
gl.TexCoord2f(0.0, 1.0); gl.Vertex3f(-1.0, 1.0, -1.0) // Top right
gl.TexCoord2f(1.0, 1.0); gl.Vertex3f( 1.0, 1.0, -1.0) // Top left
gl.TexCoord2f(1.0, 0.0); gl.Vertex3f( 1.0, -1.0, -1.0) // Bottom left
// Top Face
gl.Normal3f(0.0, 1.0, 0.0) // Normal Pointing Up
gl.TexCoord2f(1.0, 1.0); gl.Vertex3f(-1.0, 1.0, -1.0) // Top left
gl.TexCoord2f(1.0, 0.0); gl.Vertex3f(-1.0, 1.0, 1.0) // Bottom left
gl.TexCoord2f(0.0, 0.0); gl.Vertex3f( 1.0, 1.0, 1.0) // Bottom right
gl.TexCoord2f(0.0, 1.0); gl.Vertex3f( 1.0, 1.0, -1.0) // Top right
// Bottom Face
gl.Normal3f(0.0, -1.0, 0.0) // Normal Pointing Down
gl.TexCoord2f(0.0, 1.0); gl.Vertex3f(-1.0, -1.0, -1.0) // Top right
gl.TexCoord2f(1.0, 1.0); gl.Vertex3f( 1.0, -1.0, -1.0) // Top left
gl.TexCoord2f(1.0, 0.0); gl.Vertex3f( 1.0, -1.0, 1.0) // Bottom left
gl.TexCoord2f(0.0, 0.0); gl.Vertex3f(-1.0, -1.0, 1.0) // Bottom right
// Right face
gl.Normal3f(1.0, 0.0, 0.0) // Normal Pointing Right
gl.TexCoord2f(0.0, 0.0); gl.Vertex3f(1.0, -1.0, -1.0) // Bottom right
gl.TexCoord2f(0.0, 1.0); gl.Vertex3f(1.0, 1.0, -1.0) // Top right
gl.TexCoord2f(1.0, 1.0); gl.Vertex3f(1.0, 1.0, 1.0) // Top left
gl.TexCoord2f(1.0, 0.0); gl.Vertex3f(1.0, -1.0, 1.0) // Bottom left
// Left Face
gl.Normal3f(-1.0, 0.0, 0.0) // Normal Pointing Left
gl.TexCoord2f(1.0, 0.0); gl.Vertex3f(-1.0, -1.0, -1.0) // Bottom left
gl.TexCoord2f(0.0, 0.0); gl.Vertex3f(-1.0, -1.0, 1.0) // Bottom right
gl.TexCoord2f(0.0, 1.0); gl.Vertex3f(-1.0, 1.0, 1.0) // Top right
gl.TexCoord2f(1.0, 1.0); gl.Vertex3f(-1.0, 1.0, -1.0) // Top left
gl.End()
sdl.GL_SwapBuffers()
xrot += xspeed
yrot += yspeed
// Gather our frames per second
frames++
t := sdl.GetTicks()
if t-t0 >= 5000 {
seconds := (t - t0) / 1000.0
fps := frames / seconds
fmt.Println(frames, "frames in", seconds, "seconds =", fps, "FPS")
t0 = t
frames = 0
}
}
