Java tutorial
/* * This file is part of SpoutcraftAPI (http://wiki.getspout.org/). * * SpoutcraftAPI is free software: you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * SpoutcraftAPI is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package org.spoutcraft.spoutcraftapi.gui; import org.lwjgl.opengl.GL11; import org.spoutcraft.spoutcraftapi.Spoutcraft; public final class RenderUtil { /** * Draws a symmetrical polygon. Large values of segments (>50) approximate a circle. * @param cx x coordinate or the center of the circle * @param cy y coordinate for the center of the circle * @param r radius of the circle * @param numSegments to draw (number of sides to the polygon. Large values > 50 approximate a circle) */ public static void drawSymmetricalPolygon(float cx, float cy, float r, int numSegments) { float theta = 2 * 3.1415926F / ((float) numSegments); float c = (float) Math.cos(theta);//precalculate the sine and cosine float s = (float) Math.sin(theta); float t; float x = r;//we start at angle = 0 float y = 0; GL11.glBegin(GL11.GL_LINE_LOOP); for (int ii = 0; ii < numSegments; ii++) { GL11.glVertex2f(x + cx, y + cy);//output vertex //apply the rotation matrix t = x; x = c * x - s * y; y = s * t + c * y; } GL11.glEnd(); } public static void drawRectangle(int x, int y, int width, int height, int color) { int temp; if (x < width) { temp = x; x = width; width = temp; } if (y < height) { temp = y; y = height; height = temp; } float alpha = (float) (color >> 24 & 255) / 255.0F; float red = (float) (color >> 16 & 255) / 255.0F; float green = (float) (color >> 8 & 255) / 255.0F; float blue = (float) (color & 255) / 255.0F; GL11.glEnable(GL11.GL_BLEND); GL11.glDisable(GL11.GL_TEXTURE_2D); GL11.glBlendFunc(770, 771); GL11.glColor4f(red, green, blue, alpha); MinecraftTessellator tessellator = Spoutcraft.getTessellator(); tessellator.startDrawingQuads(); tessellator.addVertex((double) x, (double) height, 0.0D); tessellator.addVertex((double) width, (double) height, 0.0D); tessellator.addVertex((double) width, (double) y, 0.0D); tessellator.addVertex((double) x, (double) y, 0.0D); tessellator.draw(); GL11.glEnable(GL11.GL_TEXTURE_2D); GL11.glDisable(GL11.GL_BLEND); } public static void drawGradientRectangle(int x, int y, int gradientX, int gradientY, int colorOne, int colorTwo) { float alphaOne = (float) (colorOne >> 24 & 255) / 255.0F; float redOne = (float) (colorOne >> 16 & 255) / 255.0F; float greenOne = (float) (colorOne >> 8 & 255) / 255.0F; float blueOne = (float) (colorOne & 255) / 255.0F; float alphaTwo = (float) (colorTwo >> 24 & 255) / 255.0F; float redTwo = (float) (colorTwo >> 16 & 255) / 255.0F; float greenTwo = (float) (colorTwo >> 8 & 255) / 255.0F; float blueTwo = (float) (colorTwo & 255) / 255.0F; GL11.glDisable(GL11.GL_TEXTURE_2D); GL11.glEnable(GL11.GL_BLEND); GL11.glDisable(GL11.GL_ALPHA_TEST); GL11.glBlendFunc(770, 771); GL11.glShadeModel(GL11.GL_SMOOTH); MinecraftTessellator tessellator = Spoutcraft.getTessellator(); tessellator.startDrawingQuads(); tessellator.setColorRGBAFloat(redOne, greenOne, blueOne, alphaOne); tessellator.addVertex((double) gradientX, (double) y, 0.0D); tessellator.addVertex((double) x, (double) y, 0.0D); tessellator.setColorRGBAFloat(redTwo, greenTwo, blueTwo, alphaTwo); tessellator.addVertex((double) x, (double) gradientY, 0.0D); tessellator.addVertex((double) gradientX, (double) gradientY, 0.0D); tessellator.draw(); GL11.glShadeModel(GL11.GL_FLAT); GL11.glDisable(GL11.GL_BLEND); GL11.glEnable(GL11.GL_ALPHA_TEST); GL11.glEnable(GL11.GL_TEXTURE_2D); } public static void drawTexturedModalRectangle(int x, int y, int var3, int modalX, int modalY, int modalZ, float zLevel) { float var7 = 0.00390625F; float var8 = 0.00390625F; MinecraftTessellator tessellator = Spoutcraft.getTessellator(); tessellator.startDrawingQuads(); tessellator.addVertexWithUV((double) x, (double) (y + modalZ), (double) zLevel, (double) ((float) (var3) * var7), (double) ((float) (modalX + modalZ) * var8)); tessellator.addVertexWithUV((double) (x + modalY), (double) (y + modalZ), (double) zLevel, (double) ((float) (var3 + modalY) * var7), (double) ((float) (modalX + modalZ) * var8)); tessellator.addVertexWithUV((double) (x + modalY), (double) (y), (double) zLevel, (double) ((float) (var3 + modalY) * var7), (double) ((float) (modalX) * var8)); tessellator.addVertexWithUV((double) x, (double) y, (double) zLevel, (double) ((float) (var3) * var7), (double) ((float) (modalX) * var8)); tessellator.draw(); } }