diff options
| -rw-r--r-- | progs/trivial/tri-scissor-tri.c | 58 |
1 files changed, 47 insertions, 11 deletions
diff --git a/progs/trivial/tri-scissor-tri.c b/progs/trivial/tri-scissor-tri.c index d65502d91b..1bb15501bb 100644 --- a/progs/trivial/tri-scissor-tri.c +++ b/progs/trivial/tri-scissor-tri.c @@ -31,10 +31,14 @@ #define CI_OFFSET_1 16 #define CI_OFFSET_2 32 -GLint Width = 250, Height = 250; +GLint Width = 300, Height = 300; GLenum doubleBuffer; +/* scissor bounds */ +static GLint Left, Right, Bottom, Top; + + static void Init(void) { fprintf(stderr, "GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER)); @@ -47,26 +51,57 @@ static void Init(void) static void Reshape(int width, int height) { - glViewport(0, 0, (GLint)width, (GLint)height); glMatrixMode(GL_PROJECTION); glLoadIdentity(); glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0); glMatrixMode(GL_MODELVIEW); + + Width = width; + Height = height; + + Left = Width / 4; + Right = Width * 3 / 4; + Bottom = Height / 4; + Top = Height * 3 / 4; } static void Key(unsigned char key, int x, int y) { + int step = 2; + switch (key) { + case 'l': + Left -= step; + break; + case 'L': + Left += step; + break; + case 'r': + Right -= step; + break; + case 'R': + Right += step; + break; + case 'b': + Bottom -= step; + break; + case 'B': + Bottom += step; + break; + case 't': + Top -= step; + break; + case 'T': + Top += step; + break; + case 27: + exit(1); + default: + ; + } - switch (key) { - case 27: - exit(1); - default: - break; - } - - glutPostRedisplay(); + glutPostRedisplay(); } static void Draw(void) @@ -82,7 +117,8 @@ static void Draw(void) glVertex3f(-0.9, 0.0, -30.0); glEnd(); - glScissor(Width / 4, Height / 4, Width / 2, Height / 2); + printf("Scissor %d, %d .. %d, %d\n", Left, Bottom, Right, Top); + glScissor(Left, Bottom, Right-Left, Top-Bottom); glEnable(GL_SCISSOR_TEST); glBegin(GL_TRIANGLES); |