Unit CastleGLUtils

Check are any OpenGL errors recorded (in glGetError). If there are errors, our behavior depends on whether we were compiled with -dRELEASE. With -dRELEASE, we make WritelnWarning. This way eventual errors in release builds don't completely abort your program.

Note that the behavior on GL_OUT_OF_MEMORY is different. -dRELEASE does not matter here. Only GLOutOfMemoryError boolean dictates if we should raise an exception or merely make warning, regardless of -dRELEASE state.

Without -dRELEASE, we raise EOpenGLError. So a developer is strongly suggested to fix the code to not produce OpenGL errors, never ever.

Exceptions raised

EOpenGLError

Raise EOpenGLError for given OpenGL error code. This has calling convention suitable for registering this procedure as GLU_TESS_ERROR for gluTessCallback, or GLU_ERROR for gluQuadricCallback.

Comfortable wrappers for OpenGL glGet* that return a single value.

Guarantee that result is zero in case of OpenGL error. (Otherwise, OpenGL could leave them undefined and only set glGetError.)

Warning: this symbol is deprecated: use other methods to transform things, e.g. TUIControl position / anchors, or T3DTransform for TCastleScene, or TTransformNode in X3D

Warning: this symbol is deprecated: use other methods to transform things, e.g. TUIControl position / anchors, or T3DTransform for TCastleScene, or TTransformNode in X3D

Warning: this symbol is deprecated: use other methods to transform things, e.g. TUIControl position / anchors, or T3DTransform for TCastleScene, or TTransformNode in X3D

Warning: this symbol is deprecated: use other methods to transform things, e.g. TUIControl position / anchors, or T3DTransform for TCastleScene, or TTransformNode in X3D

Warning: this symbol is deprecated: use other methods to transform things, e.g. TUIControl position / anchors, or T3DTransform for TCastleScene, or TTransformNode in X3D

Warning: this symbol is deprecated: use other methods to transform things, e.g. TUIControl position / anchors, or T3DTransform for TCastleScene, or TTransformNode in X3D

Warning: this symbol is deprecated: instead of this, use drawing routines that take Color from parameters or properties, like TCastleFont.Print(X,Y,Color,...) or TGLImage.Color

Warning: this symbol is deprecated: instead of this, use drawing routines that take Color from parameters or properties, like TCastleFont.Print(X,Y,Color,...) or TGLImage.Color

Projection matrix ——————————————————–

Set ProjectionMatrix to given value.

For PerspectiveProjection, ZFar may have special ZFarInfinity value to create a perspective projection with far plane set at infinity. Useful e.g. for z-fail shadow volumes.

Warning: this symbol is deprecated: use DrawPrimitive2D

Draw vertical line using OpenGL. Uses current OpenGL color.

Deprecated, do not draw lines directly like this, instead use DrawPrimitive2D or UI interface drawing like Theme.Draw and TGLImageCore.Draw.

Warning: this symbol is deprecated: use DrawPrimitive2D

Draw horizontal line using OpenGL. Uses current OpenGL color.

Deprecated, do not draw lines directly like this, instead use DrawPrimitive2D or UI interface drawing like Theme.Draw and TGLImageCore.Draw.

Warning: this symbol is deprecated: use DrawPrimitive2D to draw shapes

Draw arrow shape. Arrow is placed on Z = 0 plane, points to the up, has height = 2 (from y = 0 to y = 2) and width 1 (from x = -0.5 to 0.5).

Everything is drawn CCW when seen from standard view (x grows right, y up). Uses current OpenGL color.

Warning: this symbol is deprecated: use TCastleScene to draw 3D stuff

Comfortable wrapper for gluNewQuadric. Sets all quadric parameters. Sets also the GLU_ERROR callback to ReportGLerror.

Exceptions raised

Exception

If gluNewQuadric fails (returns nil).

Warning: this symbol is deprecated: use TCastleScene to draw 3D stuff

Render sphere in OpenGL. Radius, Slices, Stacks have the same meaning as for gluSphere (in case they are not self-explanatory...). Other parameters set glu quadric parameters, see glu quadric documentation.

Warning: this symbol is deprecated: use TCastleScene to draw 3D stuff

Draw axis (3 lines) around given position. Nothing is generated besides vertex positions — no normal vectors, no texture coords, nothing.

Warning: this symbol is deprecated: instead of this, use drawing routines that take Color from parameters or properties, like TCastleFont.Print(X,Y,Color,...) or TGLImage.Color

Call glColor, taking Opacity as separate Single argument. Deprecated, do not use colors like that, instead pass TCastleColor to appropriate routines like TCastleFont.Print.

Warning: this symbol is deprecated: instead of this, use drawing routines that take Color from parameters or properties, like TCastleFont.Print(X,Y,Color,...) or TGLImage.Color

Warning: this symbol is deprecated: do not use display lists; they are not available on OpenGLES and modern OpenGL

Call glGenLists(range) and checks the result.

Exceptions raised

EOpenGLNoMoreDisplayLists

When glGenLists(Range) returned zero for non-zero Range. The exception's Message shows Place, which may describe where this is called — makes it easier to debug.

Warning: this symbol is deprecated: do not use display lists; they are not available on OpenGLES and modern OpenGL

If List <> 0 then it does glDeleteList on List and sets List to 0. In other words this is simply glDeleteList but

1. only if List really should be deleted

2. sets List to 0 after deletion

If Buffer <> 0 then it does glDeleteBuffers and sets Buffer to 0.

Set color and depth buffers writeable or not. This is just a shortcut for

    glDepthMask(Writeable);
    glColorMask(Writeable, Writeable, Writeable, Writeable);
  

Warning: this symbol is deprecated: instead of this, use drawing routines that take position as parameters, like TGLImageCore.Draw(X,Y) or TCastleFont.Print(X,Y,...)

Draw the 2D GUI stuff (like following GUI images and TCastleFont) with lower-left corner in the X,Y pixel.

Warning: this symbol is deprecated: instead of this, use drawing routines that take position as parameters, like TGLImageCore.Draw(X,Y) or TCastleFont.Print(X,Y,...)

Warning: this symbol is deprecated: instead of this, use drawing routines that take position as parameters, like TGLImageCore.Draw(X,Y) or TCastleFont.Print(X,Y,...)

Warning: this symbol is deprecated: instead of this, use drawing routines that take position as parameters, like TGLImageCore.Draw(X,Y) or TCastleFont.Print(X,Y,...)

Warning: this symbol is deprecated: instead of this, use drawing routines that take position as parameters, like TGLImageCore.Draw(X,Y) or TCastleFont.Print(X,Y,...)

Enable exactly one (or none, for Target=etNone) OpenGL texture target. Always use this instead of manually calling glDisable(GL_TEXTURE_2D), glEnable(GL_TEXTURE_2D) and such. This makes sure to have at most one texture target enabled, and disable others.

Remember that this state is different for every texture unit in OpenGL, in case you use multi-texturing.

Remember that not all texture targets are guaranteed to be supported by OpenGL. Target=etNone and Target=et2D are always supported. For the rest, check appropriate GLFeatures property (before even creating a texture with such type). If you pass an unsupported target type to this procedure, it will be ignored (all targets will be disabled, like for Target=etNone).

Note that this is only for fixed-function OpenGL pipeline. Shader pipeline completely ignores the enabled state of texture units.

Initialize GLVersion and GLUVersion and GLFeatures.

Draw a rectangle filled with a color.

Like with DrawPrimitive2D: Blending is automatically used if Color alpha < 1. ForceBlending forces the usage of blending. When it is False, we use blending only if Color[3] (alpha) < 1.

Draw a rectangle frame.

Like with DrawPrimitive2D: Blending is automatically used if Color alpha < 1. ForceBlending forces the usage of blending. When it is False, we use blending only if Color[3] (alpha) < 1.

Draw a circle. It may be scaled differently in X than Y, thus resembling an ellipse.

Like with DrawPrimitive2D: Blending is automatically used if Color alpha < 1. ForceBlending forces the usage of blending. When it is False, we use blending only if Color[3] (alpha) < 1.

Draw a circle outline. It may be scaled differently in X than Y, thus resembling an ellipse.

Like with DrawPrimitive2D: Blending is automatically used if Color alpha < 1. ForceBlending forces the usage of blending. When it is False, we use blending only if Color[3] (alpha) < 1.

Draw a simple 2D primitive with a given color. This can be used to draw a series of points, lines or triangles, depending on the Mode parameter.

Blending is automatically used if Color alpha < 1. ForceBlending forces the usage of blending. When it is False, we use blending only if Color[3] (alpha) < 1.

Parameters

LineWidth

Line width, only used when Mode indicates lines.

Note that values other than 1 are not guaranteed to be supported. While it's a fast method to have thick lines, it is implementation-limited in case of

1. desktop OpenGL with anti-aliasing, see https://www.opengl.org/sdk/docs/man/html/glLineWidth.xhtml

2. mobile OpenGLES, with or without anti-aliasing, see https://www.khronos.org/opengles/sdk/docs/man/xhtml/glLineWidth.xml

PointSize

Point size, only used when Mode indicates points.

Note that values other than 1 are not guaranteed to be supported. Mobile OpenGLES does not support setting point size like this. And desktop OpenGL limits point size in case anti-aliasing is used, see https://www.opengl.org/sdk/docs/man2/xhtml/glPointSize.xml .

Draw a rectangle that modulates colors underneath, making nice animation to AFadeColor while FadeIntensity changes from 1.0 down to 0.0.

The GLFadeRectangleLight version makes a flash to AFadeColor, then goes back to normal. It works reasonably with any color (light or dark).

The GLFadeRectangleDark version makes additional flash to blackness in the middle (so it goes from no modulation, to AFadeColor, to pure black, and then back to normal). So the "Dark" version is a little more impressive when you're flashing with a dark color.

These are nice as a screen effect, to flash some color (e.g. flash red color when the player is hurt).

Only RGB portion of AFadeColor is used.

Warning: this symbol is deprecated: use GLFadeRectangleDark, or TCastleFlashEffect with Dark = true

Warning: this symbol is deprecated: use GLFadeRectangleDark, or TCastleFlashEffect with Dark = true

Warning: this symbol is deprecated: use DrawRectangle

Draw a rectangle with blending. Deprecated, use DrawRectangle instead.

Warning: this symbol is deprecated: use DrawRectangle

Multiline string describing attributes of current OpenGL library. This simply queries OpenGL using glGet* functions about many things. Does not change OpenGL state in any way.

Note that the last line of returned string does not terminate with a newline character (so e.g. you may want to do Writeln(GLInformationString) instead of just Write(GLInformationString)).

Is GenerateMipmap avaiable. This checks some GL extensions/versions that give us glGenerateMipmap or glGenerateMipmapEXT call, used by GenerateMipmap.

Call glGenerateMipmap (or analogous function from some OpenGL extension).

Exceptions raised

EGenerateMipmapNotAvailable

If no glGenerateMipmap version is available on this OpenGL version. If you don't want to get this exception, you can always check HasGenerateMipmap before calling this.

Warning: this symbol is deprecated: use RenderContext.Clear

Possible values of DepthRange.

Values

• drFull:  
• drNear:  
• drFar:  

Values

• etNone:  
• et2D:  
• etCubeMap:  
• et3D:  

Part of CastleGLUtils unit: TGLFeatures and friends.

Values

• gsNone:  
• gsExtension:  
• gsStandard:  

Primitive to draw using DrawPrimitive2D. The modes correspond to OpenGL drawing modes, see https://www.opengl.org/wiki/Primitive https://www.opengl.org/sdk/docs/man2/xhtml/glBegin.xml

Values

• pmPoints:  
• pmLineStrip:  
• pmLineLoop:  
• pmLines:  
• pmTriangleStrip:  
• pmTriangleFan:  
• pmTriangles:  

Values

• bsSrcAlpha:  
• bsOneMinusSrcAlpha:  
• bsZero:  
• bsOne:  
• bsDstColor:  
• bsSrcColor: As a source factor only since GL 1.4, check GLFeatures.Version_1_4
• bsDstAlpha:  
• bsOneMinusDstColor:  
• bsOneMinusSrcColor: As a source factor only since GL 1.4, check GLFeatures.Version_1_4
• bsOneMinusDstAlpha:  
• bsSrcAlphaSaturate:  
• bsConstantColor:  
• bsOneMinusConstantColor:  
• bsConstantAlpha:  
• bsOneMinusConstantAlpha:  

Values

• bdSrcAlpha:  
• bdOneMinusSrcAlpha:  
• bdZero:  
• bdOne:  
• bdDstColor: As a destination factor only since GL 1.4, check GLFeatures.Version_1_4
• bdSrcColor:  
• bdDstAlpha:  
• bdOneMinusDstColor: As a destination factor only since GL 1.4, check GLFeatures.Version_1_4
• bdOneMinusSrcColor:  
• bdOneMinusDstAlpha:  
• bdConstantColor:  
• bdOneMinusConstantColor:  
• bdConstantAlpha:  
• bdOneMinusConstantAlpha:  

Part of CastleGLUtils unit: TRenderContext and friends.

Values

• cbColor:  
• cbDepth:  
• cbStencil:  

When GPU runs out of memory, raise exception (EOpenGLOutOfMemoryError) or merely make a warning. Merely making a warning is very risky (you risk all kinds of rendering artifacts), but sometimes the rendering is actually smooth even though GPU complains.

Warning: this symbol is deprecated.

Current color, set by glColorv and used for TCastleFont font printing (in case you use deprecated TCastleFont.Print overloads without explicit colors).

Instead of this, use drawing routines that take Color from parameters or properties, like TCastleFont.Print(X,Y,Color,...) or TGLImage.Color.

Current projection matrix.

For OpenGLES, this is merely a global ProjectionMatrix variable. It must be passed to various shaders to honour the projection.

For desktop OpenGL, setting this also sets fixed-function projection matrix. The OpenGL matrix mode is temporarily changed to GL_PROJECTION, then changed back to GL_MODELVIEW.

Viewport size for 2D rendering functions: DrawRectangle and TGLImageCore.Draw. UI container (like TCastleWindowCustom or TCastleControlCustom) must take care to set this before rendering.

Warning: this symbol is deprecated.

Global position for drawing 2D stuff. Do this use this. Instead of this, use drawing routines that take position as parameters, like TGLImageCore.Draw(X,Y) or TCastleFont.Print(X,Y,...).

Use this to operate on OpenGL glDepthRange. For now, our engine has very simple use for this, for TPlayer.RenderOnTop.

Current OpenGL / OpenGLES context state. Only access it during the rendering, i.e. in TUIControl.Render.