Android OpenGL ES 3D space and glDrawArrays

1. Four pyramid: composed of four triangles. Ry: consists of six triangles. Difficulty: when constructing the vertex coordinates of a 3D space, to make the object rotate around its own axis, the central coordinates of the object must always be (0.0f, 0.0f, 0.0f ), and the triangles are drawn in a counter-clockwise order. 2.3D space painting: GL_APICALL void GL_APIENTRY glDrawArrays (GLenum mode, GLint first, GLsizei count); parameter description: mode, drawing method. The following parameters are provided after OpenGL2.0: GL_POINTS, GL_LINES, GL_LINE_LOOP, GL_LINE_STRIP, GL_TRIANGLES, GL_TRIANGLE_STRIP, and GL_TRIANGLE_FAN. First, which position in the array cache is drawn, generally 0. Count, number of vertices in the array. 3. draw the vertex array: // draw the triangle cone for (int I = 0; I <4; I ++) {gl. glDrawArrays (GL10.GL _ TRIANGLE_STRIP, I * 3, 3);} // draw a ry for (int I = 0; I <6; I ++) {gl. glDrawArrays (GL10.GL _ TRIANGLE_STRIP, I * 4, 4);} [appendix] Build a vertex array: [java] int one = 0x10000; // an array of four pyramid vertices: private IntBuffer triggerBuffer = IntBuffer. wrap (new int [] {0, one, 0,-one,-one, 0, one,-one, one, 0, one,-one, one, one,-one,-one, 0, one, 0, one,-one, 0, one, 0, -one, one}); // an array of Four-body vertices: private IntBuffer quaterBuffer = IntBuffer. wrap (new int [] {one, one,-one,-one, one,-one, one,-one,-one, one,-one, one,-one, one,-one,-one, one,-one, -one, one,-one, one, one,-one, one,-one, one ,});